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What are some key differences between the sympathetic and parasympathetic nervous systems? The cell bodies of all preganglionic sympathetic neurons are in the spinal cord, while some parasympathetic preganglionic cell bodies are in the brainstem. Sympathetic ganglia are typically far from autonomic end‐organs, while parasympathetic ganglia are typically close to or in end‐organs. Norepinephrine is the transmitter of most sympathetic postganglionic neurons while acetylcholine is the transmitter of parasympathetic postganglionic neurons. Sympathetic and parasympathetic postganglionic neurons typically have opposite effects on an end‐organ; for example, sympathetic input increases heart rate while parasympathetic input decreases it. 0 0 5 1. What are some key differences between the sympathetic and parasympathetic nervous systems? 0 0 0 0 0 0 308791817.71522301435470581055 0 0 308597742.07191497087478637695 5 75D71887-95F5-45EB-B538-FA02CED45AB7-7588-000149A6371FD670 1. How does the functional organization of the cerebral cortex facilitate information processing? There is a laminar structure which organizes inputs and outputs of a particular cortical area. Information comes in to layer 4 and goes out to specific other areas from other layers. There is often a columnar organization within a cortical area (e.g. somatosensory, primary visual) that is related to the lamination, such that all of the cells in the various layers within a column are involved in processing information from one part of the receptive sheet. Also, as you’ve learned in other lectures, different areas of the cortex deal with different types of information. For example, the precentral gyrus and adjacent areas are involved in motor control, and there is a hierarchical processing of information within the motor areas. 0 0 5 1. How does the functional organization of the cerebral cortex facilitate information processing? 0 0 0 0 0 0 308791817.71979802846908569336 0 0 308599289.04445999860763549805 5 42101901-4AA4-4966-98F4-ACBFE0FCFE18-7588-000149A63699BADC 1. How do the hair cells sense head movement? Head movement causes movement of endolymph relative to hair cells. Hair cells detect movement of endolymph as deflections of the hair bundle. These deflections cause potassium channels to open or close, which depolarizes or hyperpolarizes the hair cell and causes a change in the release of neurotransmitter. 0 0 5 1. How do the hair cells sense head movement? 0 0 0 0 0 0 308791817.71101200580596923828 0 0 308597174.06127202510833740234 5 B544BEAB-B610-403E-AAFF-9C401B0E019B-7588-000149A6370A40D1 4. What brain mechanisms may mediate the enhancement of memory formation for events that occur when you are emotionally aroused? The amygdala is known to mediate enhancement of emotional memory formation via projections to the hippocampal formation and cortex. Emotional arousal leads to neurochemical and hormonal release of compounds like norepinephrine and glucocorticoids. Blocking the actions of these compounds in the basolateral amygdala impairs the enhancement of memory formation that normally occurs. 0 0 5 4. What brain mechanisms may mediate the enhancement of memory formation for events that occur when you are emotionally aroused? 0 0 0 0 0 0 308791817.71828800439834594727 0 0 308598298.09611201286315917969 5 1A7B3E02-B13F-4774-993D-B7AF2D0EE4AD-7588-000149A6361C8321 2. Describe two differences between feedback and feed‐forward control of movements. Feedback control reacts to sensory information that is subject to delays. Feed‐forward control is predictive. Feed‐forward control generates motor commands that take delays into account, and thus makes it possible to anticipate changes in the environment (for example, to move the arm to the position where a moving ball will be by the time the arm actually starts moving). 0 0 5 2. Describe two differences between feedback and feed‐forward control of movements. 0 0 0 0 0 0 308791817.70270699262619018555 0 0 308504159.67798101902008056641 5 518852AA-45D9-4F8E-8DE1-C6EEAAF63C1D-7588-000149A6370618AA 3. Why are dopaminergic neurons thought to be important for learning about CS‐US associations? Dopaminergic neurons encode reward prediction errors, i.e. they fire when a reward occurs unexpectedly. When a reward occurs unexpectedly, one must learn how to predict it accurately based on the available sensory information. This process is thought to be driven by dopaminergic neurons. 0 0 5 3. Why are dopaminergic neurons thought to be important for learning about CS‐US associations? 0 0 0 0 0 0 308791817.71801400184631347656 0 0 308598280.82336199283599853516 5 00749FF5-692F-4BF5-8521-360781EFBB1F-7588-000149A6364B8F8D 1. Define posture and locomotion. Posture is the position of body parts relative to each other and to the environment. Locomotion is the muscle‐powered movement of the body through space. 0 0 5 1. Define posture and locomotion. 0 0 0 0 0 0 308791817.70588600635528564453 0 0 308517256.64056599140167236328 5 20CB6860-621B-4EDE-BACA-D2BA06DC6EAC-7588-000149A636320D2A 3. Outline the neuronal players involved in the stretch reflex and how they contribute to limb movement. When a skeletal muscle is stretched, it activates muscle spindles which subsquently increase the firing rate of Ia primary afferent sensory fibers. The Ia sensory fibers make monosynaptic excitatory connections with motor neurons innervating the same or synergistic muscles. Depolarization (over the firing threshold) of the homonymous (and synergistic) motor neurons results in contraction of the muscle that has been stretched. At the same time, antagonistic muscles are relaxed via activation of the Ia inhibitory interneuron which hyperpolarizes the motor neurons that innervate the antagonistic muscle. 0 0 5 3. Outline the neuronal players involved in the stretch reflex and how they contribute to limb movement. 0 0 0 0 0 0 308791817.70411801338195800781 0 0 308504762.70880299806594848633 5 83FAFA56-9B3E-4F28-9485-027185CDBDCF-7588-000149A636287F95 1. A single motor neuron makes synaptic contacts with several muscle fibers, forming a motor unit. Explain why the muscle fibers innervated by the motor neuron should be of the same twitch fiber type. The muscle fibers should be of the same twitch‐fiber type (i.e. slow or FF or FFR) because different muscle fiber types produce different forces and have different metabolic demands. If precise motor control is to be achieved, a single motor neuron should activate muscle fiber types that respond identically. 0 0 5 1. A single motor neuron makes synaptic contacts with several muscle fibers, forming a motor unit. Explain why the muscle fibers innervated by the motor neuron should be of the same twitch fiber type. 0 0 0 0 0 0 308791817.70359098911285400391 0 0 308504741.31925600767135620117 5 22EFB3F3-81F2-4B68-B4B3-AED5622E7F83-7588-000149A637657A25 4. If you decide to continue an antidepressant medication beyond the initial treatment period, how long should you continue it? Effective treatment should be maintained for six months. Patients in their first episode should then be tapered off and carefully observed. Patients with a history of multiple prior episodes should usually be continued on effective treatment indefinitely, as should patients with very chronic depressive illness. 0 0 5 4. If you decide to continue an antidepressant medication beyond the initial treatment period, how long should you continue it? 0 0 0 0 0 0 308791817.72426599264144897461 0 0 308621435.19483798742294311523 5 0 5 0 0 0 0 7638D7BE-65F9-4686-9AA9-C16A94F5FBA2-7588-000149A636C2379D 0 0 100 43-Sleep 0 308597524.60914498567581176758 1 5 D98092FA-DA02-41D0-9B0B-160F90EA24A5-7588-000149A6363A188E 1. Which classes of therapeutic strategy are potentially useful for both ALS and SMA, and which are more likely to be disease‐specific? Strategies that target general cellular features of the disease process – axonal dieback, selective motor neuron death, unfolded protein response – may be considered to have a chance of success in both diseases. Those that target the specific upstream events that lead to each disease – mutant SOD1 knockdown, SMN upregulation, SMN splicing – are more likely to be disease‐specific. 0 0 5 1. Which classes of therapeutic strategy are potentially useful for both ALS and SMA, and which are more likely to be disease‐specific? 0 0 0 0 0 0 308791817.70474302768707275391 0 0 308516955.34459000825881958008 5 0 5 0 0 0 0 5E10B18C-6BA0-4618-A50E-4C10FB78A3BB-7588-000149A63789E19F 0 0 100 61-Axonal 0 308667527.52953201532363891602 1 5 B09041D0-8C6A-4E33-B369-581C0AAE0561-7588-000149A637AEDF7F 1. One important distinction between short‐ and long‐term synaptic plasticity is that the latter requires new protein synthesis. Is the involvement of cAMP another important distinction? Yes and no. An elevation of cAMP is important for short‐ as well as long‐term plasticity. However, in long‐term plasticity, the sustained elevation of cAMP affects transcription factors, which change gene expression. In short‐term plasticity, cAMP doesn’t have nuclear effects, but rather has briefer effects, such as triggering phosphorylation of ion channels. 0 0 5 1. One important distinction between short‐ and long‐term synaptic plasticity is that the latter requires new protein synthesis. Is the involvement of cAMP another important distinction? 0 0 0 0 0 0 308791817.72917801141738891602 0 0 308777817.16580301523208618164 5 0A980E17-DCA7-4DA9-B99E-62AFDF197013-7588-000149A636B8A2F4 2. The ascending arousal system is composed of the (A) raphe nuclei (B) locus coeruleus (C) tuberomammilary nucleus (D) basal nucleus of Meynert (E) all of the above (E) 0 0 5 2. The ascending arousal system is composed of the (A) raphe nuclei (B) locus coeruleus (C) tuberomammilary nucleus (D) basal nucleus of Meynert (E) all of the above 0 0 0 0 0 0 308791817.71293801069259643555 0 0 308597394.63087397813796997070 5 D820DE1C-0FEC-406E-8045-8886CAF40833-7588-000149A6371BD855 4. Describe the deficit caused by a stroke which obliterates left occipital cortex and the posterior part of the corpus callosum. The patient cannot get information from the right occipital cortex to the speech area, so he cannot read or name colors. He can write to dictation but cannot read what he has written. 0 0 5 4. Describe the deficit caused by a stroke which obliterates left occipital cortex and the posterior part of the corpus callosum. 0 0 0 0 0 0 308791817.71944099664688110352 0 0 308598602.74776601791381835938 5 11316571-717E-4CE3-8009-669CC30E2C71-7588-000149A636E36973 3. Heavy smokers sometimes develop Horner syndrome, when a lung tumor damages the superior cervical ganglion. What symptoms would you expect to see in this syndrome and why? A solution of cocaine can be used to help diagnose the syndrome; explain its use. (See the lecture on “Adrenergic Drugs” in Molecular Mechanisms of Health and Disease course for the mechanism of action of cocaine.) The superior cervical ganglion provides the sympathetic innervation of the head. Since sympathetic input causes pupil dilation, the pupil on the affected side will be smaller than on the normal side (anisocoria) and this difference will be enhanced in the dark, with only the unaffected pupil dilating. Instillation of a cocaine solution into the unaffected eye will produce pupil dilation, since cocaine causes norepinephrine released from sympathetic nerve terminals to accumulate extracellularly. However, cocaine will be ineffective in the affected eye, whose sympathetic input is impaired. Another typical symptom of Horner syndrome is reduced facial sweating. 0 0 5 3. Heavy smokers sometimes develop Horner syndrome, when a lung tumor damages the superior cervical ganglion. What symptoms would you expect to see in this syndrome and why? A solution of cocaine can be used to help diagnose the syndrome; explain its use. (See the lecture on “Adrenergic Drugs” in Molecular Mechanisms of Health and Disease course for the mechanism of action of cocaine.) 0 0 0 0 0 0 308791817.71574002504348754883 0 0 308597771.51972699165344238281 5 FEE4F6B8-4EE9-4CFC-AD31-71FF94A4F6FA-7588-000149A636C602AA 2. Several neurotransmitters are involved in sleep and wakefulness. Which 3 neurotransmitters are the driving forces in the hypothalamus? hypocretin/orexin, histamine, GABA 0 0 5 2. Several neurotransmitters are involved in sleep and wakefulness. Which 3 neurotransmitters are the driving forces in the hypothalamus? 0 0 0 0 0 0 308791817.71381497383117675781 0 0 308597553.51152902841567993164 5 7DEB1CB7-A182-49B9-9D3F-A13B669D206E-7588-000149A637618BD6 3. When should you continue current medication vs. augmenting it with additional treatment vs. switching to a different treatment? Patients who have remitted (i.e., no longer have depressive symptoms) should be continued on effective treatment at the same effective dose. Patients who have improved without remitting should also be continued but have the dose increased if tolerated and not yet at the PDR maximal dose; if still unremitted, another medication should be added as an augmenter until remission is achieved (Augment). Patients who have not experienced benefit should be discontinued and another antidepressant treatment tried (Switch). 0 0 5 3. When should you continue current medication vs. augmenting it with additional treatment vs. switching to a different treatment? 0 0 0 0 0 0 308791817.72400701045989990234 0 0 308621425.15716898441314697266 5 3012282D-3CCD-48FE-B3E8-261296451266-7588-000149A637C9FB4D 5. Gen wants to create mice that lack the ability to smell one particular odor (odor Y) but otherwise have normal olfaction. Can she do this and if so, how? Unfortunately, Gen is not likely to succeed. The best she can do is find the precise combination of odor receptors or glomeruli that respond to odor Y and ablate these receptors or glomeruli. But since these receptors also participate in the coding of other odors, the altered mice will have broader deficits that go beyond sensing odor Y. Unlike taste, odor coding is combinatorial and does not rely on labeled lines. 0 0 5 The following question is about Gen and Fran, twin sisters in Themadscientist family. They recently learned about smell and taste and immediately went to the lab to put their knowledge to test. 5. Gen wants to create mice that lack the ability to smell one particular odor (odor Y) but otherwise have normal olfaction. Can she do this and if so, how? 0 0 0 0 0 0 308791817.73085099458694458008 0 0 308779976.54938900470733642578 5 58FDF593-3A17-4878-A601-F58241D282A4-7588-000149A6367C083D 3. List the excitatory vs. inhibitory nature of the following synaptic connections: striatum to GPi (direct pathway); striatum to GPe to STN to GPi (indirect pathway); SNc to striatum striatum to GPi – inhibitory; striatum to GPe – inhibitory; GPe to STN – inhibitory; STN to GPi – excitatory; SNc to striatum ‐‐ excitatory onto direct pathway, inhibitory onto indirect pathway 0 0 5 3. List the excitatory vs. inhibitory nature of the following synaptic connections: striatum to GPi (direct pathway); striatum to GPe to STN to GPi (indirect pathway); SNc to striatum 0 0 0 0 0 0 308791817.70896500349044799805 0 0 308517832.34749501943588256836 5 0 5 0 0 0 0 9EA72EC2-0B57-4CDC-8C3C-0694905BCA1B-7588-000149A637BA2E12 0 0 100 23-Smell\u2600Taste 0 308779540.38030302524566650391 1 5 0 5 0 0 0 0 9D23171F-9697-4932-B810-A93A155887C1-7588-000149A6364D3804 0 0 100 35-Posture\u2600Loco 0 308517233.20570600032806396484 1 5 9956C79E-8337-40E3-98AC-29DD5F0BF646-7588-000149A63780565A 2. Why would knockout of Nogo not be expected to permit good regeneration in the CNS? What other single protein knockout should be more effective? Other molecules expressed by oligodendrocytes would still be available to suppress axonal growth. In theory, it would be more effective to eliminate the Nogo receptor, since these other molecules also bind to it. In fact, elimination of the Nogo receptor is not that effective in promoting regeneration, perhaps because of the presence of other receptors, like PirB. 0 0 5 2. Why would knockout of Nogo not be expected to permit good regeneration in the CNS? What other single protein knockout should be more effective? 0 0 0 0 0 0 308791817.72602498531341552734 0 0 308667590.91175299882888793945 5 17942641-0A5D-4114-A586-2A4169B538F2-7588-000149A636EB5985 5. Which cell in the circuitry of the peristaltic reflex codes for the polarity of the muscle response, where muscle oral to the food mass contracts while muscle on the other side relaxes? A. enterochromaffin cell B. IPAN C. interneuron D. motor neuron The correct answer is D. The motor neurons on the oral side are excitatory, releasing transmitters that cause contraction, while those on the anal side are inhibitory, releasing transmitters that cause relaxation. 0 0 5 5. Which cell in the circuitry of the peristaltic reflex codes for the polarity of the muscle response, where muscle oral to the food mass contracts while muscle on the other side relaxes? A. enterochromaffin cell B. IPAN C. interneuron D. motor neuron 0 0 0 0 0 0 308791817.71626102924346923828 0 0 308597798.68511599302291870117 5 8D72954A-632E-4226-B936-2270C69DAA85-7588-000149A6373AB303 4. An 8 year old boy is reported to be frequently inattentive and non‐responsive in class. Resisting an inclination to dismiss this as normal behavior, you recommend neurological testing and an EEG reveals frequent brief bouts of abnormal firing throughout the brain. Your initial thought is to prescribe phenytoin, but you hesitate because you remember that it tends to cause gingival hyperplasia. Is your thinking correct? Phenytoin does tend to cause gingival hyperplasia in children, but that is not the major reason why you shouldn’t use it here. The boy is apparently suffering absence seizures, which phenytoin will not suppress. The generalized seizures for which it is effective are tonic‐clonic seizures. Here you would probably prescribe ethosuximide, which specifically prevents absence seizures. 0 0 5 4. An 8 year old boy is reported to be frequently inattentive and non‐responsive in class. Resisting an inclination to dismiss this as normal behavior, you recommend neurological testing and an EEG reveals frequent brief bouts of abnormal firing throughout the brain. Your initial thought is to prescribe phenytoin, but you hesitate because you remember that it tends to cause gingival hyperplasia. Is your thinking correct? 0 0 0 0 0 0 308791817.72146201133728027344 0 0 308599601.94999802112579345703 5 3A8BD95F-BA4A-4B22-AA6F-6558E5F2D3F5-7588-000149A6363F911F 2. Name some ways in which reduction in levels of the SMN complex, involved in splicing in all cells, might lead to selective degeneration of motor neurons in SMA patients. SMN may be responsible for the correct splicing of a gene with a specific function in motor neurons. Motor neurons may be selectively sensitive to the loss of a ubiquitous protein whose levels are reduced by SMN loss of function. Motor neurons express naturally high levels of SMN and so may be more sensitive than other cell types to even relatively minor reductions in SMN activity. 0 0 5 2. Name some ways in which reduction in levels of the SMN complex, involved in splicing in all cells, might lead to selective degeneration of motor neurons in SMA patients. 0 0 0 0 0 0 308791817.70500397682189941406 0 0 308517038.61664098501205444336 5 85B3FA89-0773-40EC-A7E0-F955177DD43D-7588-000149A636CA0E60 3. List the stages of sleep with a one or two word descriptive term. stage 1 – light stage 2 – moderate stage 3 ‐ deep REM sleep – dream sleep 0 0 5 3. List the stages of sleep with a one or two word descriptive term. 0 0 0 0 0 0 308791817.71407902240753173828 0 0 308597557.60730302333831787109 5 A8DFC3BA-1BF4-48E5-B798-48095703BD4D-7588-000149A63695C6B4 5. What is the role of the cerebellum in the generation of saccades? The cerebellum adjusts for changes in muscular strength and differing orbital forces. 0 0 5 5. What is the role of the cerebellum in the generation of saccades? 0 0 0 0 0 0 308791817.71065300703048706055 0 0 308518123.40380299091339111328 5 3FD96012-E090-4569-8382-D303A41B1FF4-7588-000149A63758269F 1. Describe two hypotheses of why people get depressed and two reasons supporting each. Serotonin Deficiency Hypothesis ‐ there is a dearth of serotonin and its major metabolite (5‐HIAA) in the CSF, blood and post‐mortem brains of depressed patients ‐ many drugs that increase brain serotonin act as antidepressants ‐ artificial induction of serotonin deficiency produces depressed mood and depressive symptoms Norepinephrine Deficiency Hypothesis ‐ there is a dearth of norepinephrine and its major metabolite (MHPG) in the CSF, blood and post‐mortem brains of depressed patients ‐ many drugs that increase brain norepinephrine act as antidepressants ‐ artificial induction of norepinephrine deficiency produces depressed mood and depressive symptoms 0 0 5 1. Describe two hypotheses of why people get depressed and two reasons supporting each. 0 0 0 0 0 0 308791817.72348898649215698242 0 0 308621403.60133701562881469727 5 0 5 0 0 0 0 B2A842CC-3D35-4763-AAC1-80161696B4B4-7588-000149A6377C8B60 0 0 100 62-NervInj 0 308667558.30252802371978759766 1 5 79EF7293-D064-48CB-879A-0C6C9BB87099-7588-000149A63666D77A 2. What are microcomplexes? A small group of olivary cells sends climbing fibers to Purkinje cells arranged in longitudinal or sagittal zones in the cerebellar cortex. These Purkinje cells in turn converge on a small group of neurons in the DCN. Some of these DCN cells send inhibitory projections back to the same set of olivary cells that sent in the input. 0 0 5 2. What are microcomplexes? 0 0 0 0 0 0 308791817.70757699012756347656 0 0 308517666.36575800180435180664 5 FEDF7840-7511-4FCC-9EB0-35EDAEC05BE3-7588-000149A63736C0E0 3. A competitive antagonist at the GABA receptor should considerably reduce the activity of a barbiturate BECAUSE the antagonist should considerably reduce the binding of the barbiturate to the GABA receptor. A. Both statements are true and they are related. B. Both statements are true but they are not related. C. The first statement is true and the second statement is false. D. The first statement is false and the second statement is true. E. Both statements are false. The correct answer is C. A competitive antagonist will compete with GABA for binding to the receptor, so less GABA will bind. Since barbiturates work at the GABA receptor by enhancing the action of GABA, their activity will be reduced. Barbiturates bind to a different site on the GABA receptor complex than does GABA, which makes sense since barbiturates enhance, rather than mimic, the action of GABA. Therefore, the competitive antagonist should not affect their binding to the receptor. 0 0 5 3. A competitive antagonist at the GABA receptor should considerably reduce the activity of a barbiturate BECAUSE the antagonist should considerably reduce the binding of the barbiturate to the GABA receptor. A. Both statements are true and they are related. B. Both statements are true but they are not related. C. The first statement is true and the second statement is false. D. The first statement is false and the second statement is true. E. Both statements are false. 0 0 0 0 0 0 308791817.72120201587677001953 0 0 308599590.34028202295303344727 5 32D09B8D-67FA-4AF7-AEBF-65AB5916AA7B-7588-000149A637998BD5 5. Would inhibition of caspases affect neuronal survival in the NGF knockout mouse? The inhibition of caspases would prevent the large‐scale apoptosis of NGF‐dependent neurons expected in the NGF knockout mouse, since caspases are essential for the cell death cascade that NGF normally suppresses. 0 0 5 5. Would inhibition of caspases affect neuronal survival in the NGF knockout mouse? 0 0 0 0 0 0 308791817.72767597436904907227 0 0 308667754.96177297830581665039 5 01E239B6-65D8-447A-A45A-5880CC581891-7588-000149A637503B13 4. How has functional brain imaging been useful for research into the neurobiology of drug addiction? Advances in brain imaging let us view human brain activity in addiction at a level previously achieved only with invasive procedures in animal models. PET scans and fMRI can track neural activity and neurotransmitter function in living human addicts during drug use and treatment; previously, we could do so only in animal models, using depth microelectrodes to record neural activity and destructive one‐time procedures (autoradiography) for receptor mapping. Imaging also lets us correlate brain function directly to verbal reports about the addict’s internal state, providing psychological data about addiction (e.g. craving) that is inaccessible in animal models. Finally, functional imaging has aided translation of findings between animal models and human studies by demonstrating many cross‐species parallels in neural circuitry involved in the reinforcing effects of addictive drugs. 0 0 5 4. How has functional brain imaging been useful for research into the neurobiology of drug addiction? 0 0 0 0 0 0 308791817.72287398576736450195 0 0 308603296.81352299451828002930 5 4DED7F9A-3E38-4239-8FFF-47A321D32368-7588-000149A63795935D 4. Consider a genetically altered mouse in which the gene coding for NGF had been knocked out. 1) Most of its primary sensory neurons would die during development. 2) If a sensory target (let’s say the skin) were flooded with very large amounts of NGF as axons arrived, and that perfusion were maintained throughout development, the number of surviving axons innervating that target would be approximately the same as in a genetically unaltered, unperfused mouse. A. statement 1 is true, 2 is true B. statement 1 is true, 2 is false C. statement 1 is false, 2 is true D. statement 1 is false, 2 is false The correct answer is D. Different types of neuron depend on different neurotrophic factors. Many primary sensory neurons, e.g. muscle afferents, do not depend on NGF. If the skin were flooded with NGF during development, there would not be a competition for a limited supply as normally seen and there would be less cell death than normal. It would be equivalent to the Hamburger experiment in which he implanted an extra limb bud. 0 0 5 4. Consider a genetically altered mouse in which the gene coding for NGF had been knocked out. 1) Most of its primary sensory neurons would die during development. 2) If a sensory target (let’s say the skin) were flooded with very large amounts of NGF as axons arrived, and that perfusion were maintained throughout development, the number of surviving axons innervating that target would be approximately the same as in a genetically unaltered, unperfused mouse. A. statement 1 is true, 2 is true B. statement 1 is true, 2 is false C. statement 1 is false, 2 is true D. statement 1 is false, 2 is false 0 0 0 0 0 0 308791817.72741800546646118164 0 0 308667722.41914397478103637695 5 3A87A99D-910A-48D9-8097-5B6DE30E64AA-7588-000149A63654FF37 3. What are the different temporal events of the step cycle? First is the swing phase in which the leg projects forward. This involves flexion around several joints followed by extension. Contact of the foot with the ground starts the stance phase, which initially involves flexion at some joints followed by extension at all joints. 0 0 5 3. What are the different temporal events of the step cycle? 0 0 0 0 0 0 308791817.70641398429870605469 0 0 308517271.60699802637100219727 5 0 5 0 0 0 0 F7ECAC95-A31C-46B5-8BB0-CD9A15809916-7588-000149A6376B1DBB 0 0 100 58-AntiP 0 308620732.29839497804641723633 1 5 443B7B07-C26A-4817-807A-19ADAF205EAA-7588-000149A637295CB0 3. A patient was observed to have a generalized tonic‐clonic seizure without any focal features. However, an EEG showed focal spikes over the right frontal region. This patient most likely had A. an idiopathic generalized seizure. B. a secondarily generalized seizure. C. a seizure associated with Lennox Gastaut syndrome. D. an unclassified seizure. The seizure was most likely secondarily generalized. Seizures arising from the rostral frontal lobe are often “silent” until the discharge spreads into a clinically symptomatic area. Some seizures arising from the rostral frontal lobe spread posteriorly, and the initial manifestation may be a postural motor seizure from involvement of the supplementary motor area. Others spread down into the thalamus and then rapidly generalize. The combination of a clinically generalized convulsive seizure and an EEG indicating a focal discharge in the right frontal lobe suggests the latter pattern of spread: to the thalamus and then rapid generalization. Localizing information often comes from a combination of data, such as clinical characteristics of the seizure, EEG abnormalities, and MRI findings. 0 0 5 3. A patient was observed to have a generalized tonic‐clonic seizure without any focal features. However, an EEG showed focal spikes over the right frontal region. This patient most likely had A. an idiopathic generalized seizure. B. a secondarily generalized seizure. C. a seizure associated with Lennox Gastaut syndrome. D. an unclassified seizure. 0 0 0 0 0 0 308791817.72032600641250610352 0 0 308599326.86793100833892822266 5 22C4AA27-502C-450F-B010-F40958566506-7588-000149A63651036B 2. What are the different vestibular and neck reflexes that play a role in posture? vestibulospinal, vestibulocollic, cervicocollic, cervicospinal 0 0 5 2. What are the different vestibular and neck reflexes that play a role in posture? 0 0 0 0 0 0 308791817.70614701509475708008 0 0 308517261.99837899208068847656 5 402197F8-0269-4987-9FB3-844DE4C03C9A-7588-000149A63772DE28 3. Which of these medications are partial agonists? a. only aripiprazole b. both aripiprazole and risperidone c. only risperidone d. aripiprazole and D‐serine e. risperidone and D‐serine (D) 0 0 5 3. Which of these medications are partial agonists? a. only aripiprazole b. both aripiprazole and risperidone c. only risperidone d. aripiprazole and D‐serine e. risperidone and D‐serine 0 0 0 0 0 0 308791817.72514200210571289062 0 0 308621671.73519301414489746094 5 EFDB1391-3E4B-49B2-8499-D43C1C58F86D-7588-000149A6376EE8C0 2. You meet a young man with schizophrenia who has had trials of two antipsychotics, Risperidone and Olanzapine, at sufficient doses for sufficient periods of time with likely compliance but little effect on symptoms. a. What medication might you try next? b. What are the potential risks associated with this medication? a. Clozapine would be indicated as it has efficacy for psychotic symptoms which have proven refractory to treatment with other antipsychotics. b. Risks include agranulocytosis, cardiomyopathy, seizures, paralytic ileus, and diabetes. 0 0 5 2. You meet a young man with schizophrenia who has had trials of two antipsychotics, Risperidone and Olanzapine, at sufficient doses for sufficient periods of time with likely compliance but little effect on symptoms. a. What medication might you try next? b. What are the potential risks associated with this medication? 0 0 0 0 0 0 308791817.72488301992416381836 0 0 308621641.34220600128173828125 5 0 5 0 0 0 0 8441D46D-AA13-4C13-87F9-5AC9E2B19E61-7588-000149A6363BC75A 0 0 100 33-MotNeurDisease 0 308516937.86989599466323852539 1 5 0 5 0 0 0 0 71E29FEF-7568-438E-BB92-F0FFCD969394-7588-000149A636744C5C 0 0 100 38-BasGanglia 0 308517754.81776797771453857422 1 5 0 5 0 0 0 0 857AE987-534C-4C41-A6FA-C56F97243F1B-7588-000149A637B09DFD 0 0 100 66-Learning 0 308777736.28166300058364868164 1 5 4ED48070-1125-487F-92C1-4905E40894AD-7588-000149A6368DCEA1 3. What is the role of the substantia nigra pars reticulata in the generation of saccades? The substantia nigra pars reticulata sends a constant GABAergic inhibitory signal to the superior colliculus, unless it is inhibited by the frontal cortex via the caudate. This inhibition allows the colliculus to fire, driving the saccade. 0 0 5 3. What is the role of the substantia nigra pars reticulata in the generation of saccades? 0 0 0 0 0 0 308791817.71013200283050537109 0 0 308518096.25509899854660034180 5 0 5 0 0 0 0 4D9480E9-A5F4-40D8-815D-A5C9100E7E33-7588-000149A6372F004D 0 0 100 49-Barb\u2600AntiE 0 308599500.38358402252197265625 1 5 7F9FA3BF-B9DB-4D13-BDD9-158F5E46E0E3-7588-000149A637AAE42C 4. Define “critical period.” Name three factors that regulate the timing of the critical period for binocular interactions in the primary visual cortex. The critical period is the time window during which a developing neuronal circuit is especially malleable by environmental inputs. Inhibition by GABAergic basket cells, the perineuronal net and myelination are 3 factors that seem to contribute to the regulation of the timing of the critical period. 0 0 5 4. Define “critical period.” Name three factors that regulate the timing of the critical period for binocular interactions in the primary visual cortex. 0 0 0 0 0 0 308791817.72881501913070678711 0 0 308777774.98486000299453735352 5 95536226-960C-498A-9687-0A66FDB824E3-7588-000149A637254546 2. Focal seizures elicit symptoms and signs that reflect the function of both the area in which the seizure originates, and areas that may be subsequently involved as the seizure discharge spreads. What would likely be the initial manifestations of a seizure that arises in the A. primary visual cortex? B. uncus of the medial temporal lobe? C. supplementary motor area? D. superior temporal gyrus? Initial manifestations of seizures arising in the following cortical areas: A. Primary visual cortex: elementary visual hallucinations such as flashing or flickering lights, colored lights, weaving or zigzag patterns in the contralateral visual field. Sometimes there is dimming of vision or even complete blindness. B. Uncus of the medial temporal lobe: olfactory hallucinations, usually unpleasant (“burning rubber”); sometimes gustatory hallucinations, often bitter, metallic or acidic. C. Supplementary motor area: Postural seizures, classically abduction, elevation and external rotation of the contralateral arm with elbow flexed; head and eyes deviated as if looking at the arm; contralateral extension of the arm and leg – so‐called “Fencer’s posture” D. Superior temporal gyrus: simple sounds such as clicks, buzzing or drumming often identified as coming from the opposite ear; occasionally vertigo; rarely musical hallucinations 0 0 5 2. Focal seizures elicit symptoms and signs that reflect the function of both the area in which the seizure originates, and areas that may be subsequently involved as the seizure discharge spreads. What would likely be the initial manifestations of a seizure that arises in the A. primary visual cortex? B. uncus of the medial temporal lobe? C. supplementary motor area? D. superior temporal gyrus? 0 0 0 0 0 0 308791817.72006398439407348633 0 0 308599297.49461901187896728516 5 B0CC466B-1C4B-4EC0-9059-C42162E6B7BE-7588-000149A637022A1B 2. Why is the amygdala thought to mediate unconscious emotional processes? One example of unconscious emotional processing is the conditioning of autonomic responses. In patients with amygdala lesions, exposure to Pavlovian fear conditioning does not condition skin conductance responses, but the patients are consciously aware of the CS‐US pairing they have experienced. 0 0 5 2. Why is the amygdala thought to mediate unconscious emotional processes? 0 0 0 0 0 0 308791817.71775597333908081055 0 0 308598276.77811300754547119141 5 0 5 0 0 0 0 A011FF4B-44D8-44C6-ACDD-94DF168DCB70-7588-000149A6379F297B 0 0 100 65-SynapticConn 0 308777705.44300299882888793945 1 5 0 5 0 0 0 0 2F266620-BB2D-4DAD-BE83-FC8EDA89F62E-7588-000149A636F0F89D 0 0 100 45-Hypothalamus 0 308598065.86962300539016723633 1 5 D8AD7703-17D7-4FA2-AB90-102DE0D244B7-7588-000149A636801ADA 4. Complete the following sentences: a. Normal conditions: dopamine from the ___ causes ____ of the direct pathway and ____ of the indirect pathway. Because the direct pathway ______ movement and the indirect pathway _______ movement, the net effect of dopamine is to ____ movement. b. Parkinson's disease: reduced dopamine causes reduced activity in the _____ pathway, and reduced inhibition of the ____ pathway, leading to increased _____ activity and the reduction of movement. c. Huntington's disease: degeneration of striatal neurons in the ____ pathway leads to reduced activity in the _____, which results in the emergence of involuntary movements. a. SNc, excitation, inhibition, facilitates, inhibits, facilitate b. direct, indirect, GPi c. indirect, GPi 0 0 5 4. Complete the following sentences: a. Normal conditions: dopamine from the ___ causes ____ of the direct pathway and ____ of the indirect pathway. Because the direct pathway ______ movement and the indirect pathway _______ movement, the net effect of dopamine is to ____ movement. b. Parkinson's disease: reduced dopamine causes reduced activity in the _____ pathway, and reduced inhibition of the ____ pathway, leading to increased _____ activity and the reduction of movement. c. Huntington's disease: degeneration of striatal neurons in the ____ pathway leads to reduced activity in the _____, which results in the emergence of involuntary movements. 0 0 0 0 0 0 308791817.70923501253128051758 0 0 308517842.67112797498703002930 5 257A7AF2-3C28-4496-AAB8-C0118B381E55-7588-000149A636CE115A 4. List 3 characteristics of REM sleep that distinguish it from the other stages. eye movements, paralysis, distinctive EEG, variable heart and respiratory rates 0 0 5 4. List 3 characteristics of REM sleep that distinguish it from the other stages. 0 0 0 0 0 0 308791817.71434301137924194336 0 0 308597573.87071597576141357422 5 0 5 0 0 0 0 40B14909-A32A-4B6D-BB36-527470D61CBD-7588-000149A63662F9C9 0 0 100 37-Cerebellum 0 308517401.92256200313568115234 1 5 7697C7D3-9914-4562-AE81-DCB05EF7CD7E-7588-000149A636A33902 3. What is the brainstem pathway for the horizontal vestibuloocular reflex? Medial vestibular nucleus – contralateral abducens nucleus (VI) – ipsilateral oculomotor nucleus (III) 0 0 5 3. What is the brainstem pathway for the horizontal vestibuloocular reflex? 0 0 0 0 0 0 308791817.71153402328491210938 0 0 308597193.18776702880859375000 5 41D5F4A8-3E95-4625-9D0E-199C5C55BB6F-7588-000149A637844526 3. Does successful axonal regeneration in the PNS require that the distal part of the severed axon remain viable so that the outgrowing proximal part can reconnect with it? No. The distal part degenerates. Successful regeneration of the severed axon would involve growth and reconnection of the proximal part with targets. 0 0 5 3. Does successful axonal regeneration in the PNS require that the distal part of the severed axon remain viable so that the outgrowing proximal part can reconnect with it? 0 0 0 0 0 0 308791817.72628301382064819336 0 0 308667607.03135299682617187500 5 2904893B-E186-4FF2-BC23-38BBEE7BDB98-7588-000149A636614845 1. Compare and contrast the main inputs to the cerebellum in terms of their synaptic arrangement, physiological effects and possible functional roles. A Purkinje cell receives a powerful input from a single olivary neuron. This climbing fiber wraps around the dendrites of the Purkinje cell and evokes a large all‐or‐none depolarization and calcium spike known as a complex spike. It is the most powerful synapse in the brain, is infrequent, drives plasticity and may alter dendritic integration. Mossy fibers carry input from many sources in the brain. Their input is relayed by the parallel fiber axons of granule cells. Each Purkinje cell has many, many parallel fiber synapses on dendritic spines and each parallel fiber contacts hundreds of Purkinje cells, so there is both divergence and convergence of information originating in mossy fibers. The effect of an individual parallel fiber is very weak. Parallel fibers shape the simple spike output of Purkinje cells. 0 0 5 1. Compare and contrast the main inputs to the cerebellum in terms of their synaptic arrangement, physiological effects and possible functional roles. 0 0 0 0 0 0 308791817.70731800794601440430 0 0 308517629.67027199268341064453 5 A317254D-6D2B-49EE-B370-79013E4A0544-7588-000149A636AF3ABC 6. What is VOR plasticity and what controls it? VOR plasticity is a change in the gain of the VOR. It is controlled by the cerebellum. 0 0 5 6. What is VOR plasticity and what controls it? 0 0 0 0 0 0 308791817.71232002973556518555 0 0 308597235.47235900163650512695 5 DB2D520B-DB4E-4CBA-8109-69E175DFE0AE-7588-000149A6375D985C 2. What are three principles of treating depressed patients with antidepressant medication? Principle #1 ‐ treat to remission Principle #2 ‐ push dose to PDR maximum, if tolerated Principle #3 ‐ continue on PDR maximum or maximally tolerated dose for at least four weeks 0 0 5 2. What are three principles of treating depressed patients with antidepressant medication? 0 0 0 0 0 0 308791817.72374802827835083008 0 0 308621409.12572097778320312500 5 14C604D3-6AF1-4750-9456-A24DAF7D5154-7588-000149A637A2FA33 2. Suppose you blocked the synthesis of subunits of nAChRs shortly before a growing motor axon reached a muscle. Would this affect the pattern of nAChRs that developed? Yes, to an extent. nAChRs would still disappear from extrajunctional regions, as they moved into clusters at the junctional region. So the original small clusters at the junctional region would presumably enlarge. But they would not get nearly as large as normal, because insertion of newly synthesized receptors would be blocked. 0 0 5 2. Suppose you blocked the synthesis of subunits of nAChRs shortly before a growing motor axon reached a muscle. Would this affect the pattern of nAChRs that developed? 0 0 0 0 0 0 308791817.72829598188400268555 0 0 308777761.45356100797653198242 5 46051C2B-4F12-43D0-A3FA-2986C62EC817-7588-000149A636BC97EE 3. The vagus nerve innervates the (A) lung (B) heart (C) esophagus (D) stomach (E) all of the above (E) 0 0 5 3. The vagus nerve innervates the (A) lung (B) heart (C) esophagus (D) stomach (E) all of the above 0 0 0 0 0 0 308791817.71319699287414550781 0 0 308597463.62648701667785644531 5 9190AF7A-1493-4E18-AADA-4F716B91A9F1-7588-000149A6366EB2EB 4. What is the evidence for involvement of the cerebellum in non‐motor functions? Transneuronal tracing has revealed loops from prefrontal cortex to the pons to the lateral hemispheres and back to the prefrontal cortex via the thalamus. There are similar findings from diffusion tensor imaging in humans. FMRI studies have shown activity in the cerebellum in a variety of non‐motor tasks. There is some evidence for sensory, emotional, and cognitive deficits in cerebellar patients. 0 0 5 4. What is the evidence for involvement of the cerebellum in non‐motor functions? 0 0 0 0 0 0 308791817.70809197425842285156 0 0 308517684.27444899082183837891 5 0BE86F57-D045-4750-A4B1-04A52F518118-7588-000149A6378DABD1 2. An axon grows into an area where its growth cone is flanked on one side, at some distance away, by cells secreting netrin and on the other side, at a similar distance away, by cells secreting a neurotransmitter. The neurotransmitter causes the concentration of cAMP in the growth cone to decrease greatly. The growth cone has the DCC receptor for netrin on its surface. The axon will A. continue to grow straight ahead. B. turn to grow towards the cells secreting the neurotransmitter. C. turn to grow towards the cells secreting netrin. D. stop growing. The correct answer is B. Binding of netrin to the DCC receptor would normally have a positive effect, causing the axon to turn and grow towards the cells secreting it. However, the decrease in cAMP in the growth cone caused by the transmitter converts netrin into a repulsive cue. Thus, the axon turns and grows away from the cells secreting netrin, i.e. towards the cells secreting the transmitter. 0 0 5 2. An axon grows into an area where its growth cone is flanked on one side, at some distance away, by cells secreting netrin and on the other side, at a similar distance away, by cells secreting a neurotransmitter. The neurotransmitter causes the concentration of cAMP in the growth cone to decrease greatly. The growth cone has the DCC receptor for netrin on its surface. The axon will A. continue to grow straight ahead. B. turn to grow towards the cells secreting the neurotransmitter. C. turn to grow towards the cells secreting netrin. D. stop growing. 0 0 0 0 0 0 308791817.72689902782440185547 0 0 308667656.16365098953247070312 5 10B2E921-8B0F-4789-AE91-2DB944509967-7588-000149A6370E3E83 1. Describe the Wisconsin Card Sort test and the typical deficit patients show with this task. The subject is presented with a deck of cards, each of which has 1 to 4 synmbols on it, differing in number, color, and pattern. The subject is asked to sort the cards but is not told the criterion; the examiner just says right or wrong. The subject learns by trial and error what the criterion is (color, number, or pattern). Then the examiner changes the sorting criterion (e.g. from number to color), and the subject must change the strategy. Frontal patients have difficulty changing strategy once they have solved the problem the first time. 0 0 5 1. Describe the Wisconsin Card Sort test and the typical deficit patients show with this task. 0 0 0 0 0 0 308791817.71864497661590576172 0 0 308598411.72734701633453369141 5 58AEC856-B6C5-44F3-980D-6F7AF8D5D7CC-7588-000149A6367814A8 2. What are the main input and output nuclei of the basal ganglia? striatum (input), GPi (output) 0 0 5 2. What are the main input and output nuclei of the basal ganglia? 0 0 0 0 0 0 308791817.70870697498321533203 0 0 308517811.34020102024078369141 5 0 5 0 0 0 0 D28B7DE9-60D8-41FD-93A9-50257B72BE9A-7588-000149A636DBAB56 0 0 100 44-Autonomic 0 308597712.27217900753021240234 1 5 F8725464-C449-4008-9B8E-3DCF29669584-7588-000149A636438486 3. More than 140 mutations in different amino acids throughout the structure of the SOD1 enzyme trigger forms of ALS that are clinically similar. What conclusions can you draw from this? These findings make it unlikely that loss of a specific function, such as enzymatic dismutase activity, underlies the pathogenic nature of mutant SOD1 proteins. Even the idea that a specific protein‐protein interaction domain is lost is not supported by the widely scattered mutation sites. The most likely conclusion from this observation – and this is now supported by other experimental data – is that any small change in the tertiary structure of the SOD1 protein leads to a misfolded protein that can trigger an unfolded protein response (UPR). 0 0 5 3. More than 140 mutations in different amino acids throughout the structure of the SOD1 enzyme trigger forms of ALS that are clinically similar. What conclusions can you draw from this? 0 0 0 0 0 0 308791817.70526200532913208008 0 0 308517055.56611299514770507812 5 A13B8994-3606-4E12-AC43-E33489127B0B-7588-000149A6377AE099 1. Discuss the effects (positive or negative) of the various types of glial cells on nerve regeneration in the PNS and CNS. Schwann cells promote regeneration in the PNS by coating the walls of tubes through which regenerating axons grow. They provide a favorable substrate for growth by expressing on their surface molecules such as laminin. Also, they secrete growth‐promoting molecules. Oligodendrocytes inhibit growth in the CNS by expressing on their surface growth‐inhibiting molecules such as Nogo. Astrocytes and microglia proliferate at the site of injury, contributing to a glial scar rich in chondroitin sulfate, which inhibits axonal growth. 0 0 5 1. Discuss the effects (positive or negative) of the various types of glial cells on nerve regeneration in the PNS and CNS. 0 0 0 0 0 0 308791817.72576498985290527344 0 0 308667584.89300602674484252930 5 0 5 0 0 0 0 DAF6E3EB-E3F0-4D07-B133-668CBC454734-7588-000149A63685D35F 0 0 100 40-Occulomotor 0 308517960.01532900333404541016 1 5 F2955AFA-FB82-4C0C-8B0F-D02A67FF6FD3-7588-000149A637697225 1. Neurotransmitters known to be involved in the generation of psychotic symptoms include: a. only dopamine b. only dopamine and serotonin c. only dopamine and glutamate d. only dopamine, serotonin and glutamate e. only dopamine, serotonin, glutamate and norepinephrine (D) 0 0 5 1. Neurotransmitters known to be involved in the generation of psychotic symptoms include: a. only dopamine b. only dopamine and serotonin c. only dopamine and glutamate d. only dopamine, serotonin and glutamate e. only dopamine, serotonin, glutamate and norepinephrine 0 0 0 0 0 0 308791817.72462201118469238281 0 0 308621586.98953497409820556641 5 AD14E8BD-6A04-4D7B-92C5-AA7C4C26F3EE-7588-000149A637BE07BA 2. Gen Themadscientist surgically ablated the circumvallate papillae in several mice. She predicts that the mice will lose bitter sensation. Is she correct, and why? Gen is incorrect. Each papilla contains taste cells sensitive to all modalities (sweet, bitter, umami, etc.). Ablating the circumvallate papillae will impair taste sensation at the base (back) of the tongue but will do so in diffuse fashion, for all taste modalities. 0 0 5 The following question is about Gen and Fran, twin sisters in Themadscientist family. They recently learned about smell and taste and immediately went to the lab to put their knowledge to test. 2. Gen Themadscientist surgically ablated the circumvallate papillae in several mice. She predicts that the mice will lose bitter sensation. Is she correct, and why? 0 0 0 0 0 0 308791817.73006802797317504883 0 0 308779855.56452697515487670898 5 4B4836B8-0069-4338-8911-0732A0B02E25-7588-000149A6374C50E3 3. Describe some of the evidence that the nucleus accumbens (NAcc) and the ventral tegmental area (VTA) play an important role in addictive behavior. Evidence that the VTA‐NAcc system is important in addiction: • Olds and Milner discovered sites around the hypothalamus that strongly reinforced repeated electrical self‐stimulation, even to the point of ignoring food. These electrical stimulation sites were in the medial forebrain bundle, which is strongly connected to the VTA‐NAcc system. • Drug microinjection studies later provided direct evidence of reinforcing “hot spots” in the VTA and NAcc. • Most drugs of abuse have an impact on dopamine neurotransmission and dopamine is the major transmitter between the VTA and NAcc. • Consistent with these findings from laboratory animals, imaging studies show that in humans, NAcc activity correlates with drug‐induced “high” sensations. 0 0 5 3. Describe some of the evidence that the nucleus accumbens (NAcc) and the ventral tegmental area (VTA) play an important role in addictive behavior. 0 0 0 0 0 0 308791817.72261500358581542969 0 0 308603285.68243497610092163086 5 6905495C-C2FB-4DD3-83C6-9D60FCBC8EC4-7588-000149A636B32C5F 1. How does an organism generate a set of coordinated responses to an environmental challenge? (You may pick a specific example). One example would be the “fight or flight” response that engages the amygdala and downstream of it a series of brain stem nuclei such as the parabrachial nucleus, the locus coeruleus and the dorsal motor nucleus of the vagus. Another example would be the ascending arousal system that consists of several brain stem nuclei such as the locus coeruleus, the raphe nuclei and the parabrachial nucleus, as well as hypothalamic and basal forebrain nuclei, that determine levels of wakefulness and vigilance. 0 0 5 1. How does an organism generate a set of coordinated responses to an environmental challenge? (You may pick a specific example). 0 0 0 0 0 0 308791817.71267700195312500000 0 0 308597360.58887797594070434570 5 0 5 0 0 0 0 45BAC2EF-D37F-4F10-92BA-66EE8725F48C-7588-000149A636187CDD 0 0 100 30-IntroMotSys 0 308504068.64039999246597290039 1 5 0 5 0 0 0 0 F17A19EF-D0E9-49B9-A2C2-FB08FE577866-7588-000149A637218086 0 0 100 48-Epilepsy 0 308598743.33811700344085693359 1 5 F3825B1A-81E1-4292-B13B-2ABBBCDF25D5-7588-000149A6365D489E 5. List the supraspinal areas and their contribution to locomotion. The medullary reticular formation controls the speed of locomotion. The mesencephalic locomotor region regulates the gait and rate of stepping. The cerebellum fine tunes the locomotor pattern. The motor cortex is involved in path planning and obstacle avoidance. 0 0 5 5. List the supraspinal areas and their contribution to locomotion. 0 0 0 0 0 0 308791817.70695298910140991211 0 0 308517297.17203700542449951172 5 4FFC6088-1161-4921-8F5C-FCD9BC53DB49-7588-000149A636C08ACA 1. What about the sleep wake cycling makes it a circadian rhythm? What organizes that rhythm? Sleep and wakefulness cycle over about 24 hours and therefore comprise a circadian rhythm. Light impacting on the suprachiasmatic nucleus of the hypothalamus organizes the sleep wake cycle. 0 0 5 1. What about the sleep wake cycling makes it a circadian rhythm? What organizes that rhythm? 0 0 0 0 0 0 308791817.71355402469635009766 0 0 308597536.15892201662063598633 5 96E08CAC-D5E2-4292-A4A0-60F486199F8F-7588-000149A6373EA833 5. How is valproic acid unusual among mainstay antiepileptic drugs? Do its cellular and molecular mechanisms of action differ from the other drugs? In addition to a structure which is unlike other major antiepileptic drugs, valproic acid is unusual in suppressing absence seizures as well as tonic‐clonic and partial seizures. The mechanisms by which valproic acid prevents seizures are not clearly understood. 0 0 5 5. How is valproic acid unusual among mainstay antiepileptic drugs? Do its cellular and molecular mechanisms of action differ from the other drugs? 0 0 0 0 0 0 308791817.72171998023986816406 0 0 308599606.06591898202896118164 5 ABAC75C3-6545-4D02-BB92-BBF678336602-7588-000149A637883733 1. How do actin filaments advance the growth cone? Polymerization of actin filaments pushes the plasma membrane at the leading edge of the growth cone forward in the form of filopodia and veils. Also, coupling of the substrate to the retrogradely flowing network of actin filaments creates tension, which promotes the advance of microtubules and their associated organelles. 0 0 5 1. How do actin filaments advance the growth cone? 0 0 0 0 0 0 308791817.72663801908493041992 0 0 308667649.36489701271057128906 5 9CDD846E-B868-4FF2-8238-FCD8567C1937-7588-000149A63742CB68 1. Describe the three phases of the addiction cycle in terms of observable behavior. Then describe the internal/psychological state associated with each of these three phases. The three phases of the addiction cycle and their accompanying internal/psychological states (in parentheses) are: • Drug taking (intoxication: euphoria, “rush”; loss of control over intake) • Cessation of intake (tolerance to intoxicating effects, aversive withdrawal effects; impaired social, family, work interests) • Drug seeking (craving, preoccupation with obtaining more drug despite physical or psychological problems caused by drug use) 0 0 5 1. Describe the three phases of the addiction cycle in terms of observable behavior. Then describe the internal/psychological state associated with each of these three phases. 0 0 0 0 0 0 308791817.72208899259567260742 0 0 308603221.64974802732467651367 5 8AF46766-6423-4923-AB04-1CB2D8FC3567-7588-000149A6364793D0 4. Expression of mutant SOD1 in all tissues of transgenic mice causes a disease very similar to ALS. When the mutant SOD1 is selectively removed from activated microglia of these mice, the disease starts at the usual time but progresses much more slowly. What does this result tell us about: a. the role of mutant SOD1 in inflammation? b. the pathogenic role of SOD1 expressed by activated microglia? c. the pathogenic role of SOD1 expressed by microglia in general? 4a. Nothing. In fact, in these animals, inflammation proceeds as normal, but lifespan is prolonged. This suggests that the role of inflammation per se is relatively minor. 4b. The mutant SOD1 expressed in activated microglia does not contribute to the pre‐ symptomatic stages of the disease but plays a key role in the catastrophic breakdown of the neuromuscular system later in the disease. One likely hypothesis is that activated microglia may secrete a toxic factor that contributes to this breakdown. 4c. This result may underestimate the role of mutant SOD1 in microglia in general. If mutant microglia also contribute to the early stages of the disease, this would not be detected in these experiments because the gene ablation of the mutant SOD1 only occurs once each microglial cell becomes activated. 0 0 5 4. Expression of mutant SOD1 in all tissues of transgenic mice causes a disease very similar to ALS. When the mutant SOD1 is selectively removed from activated microglia of these mice, the disease starts at the usual time but progresses much more slowly. What does this result tell us about: a. the role of mutant SOD1 in inflammation? b. the pathogenic role of SOD1 expressed by activated microglia? c. the pathogenic role of SOD1 expressed by microglia in general? 0 0 0 0 0 0 308791817.70552897453308105469 0 0 308517067.21370697021484375000 5 2285E6D2-44B2-47C3-97A6-5742804C3569-7588-000149A63776E455 4. Which of these is NOT evidence in support of glutamate being related to psychosis? a. PCP challenge leads to transient psychotic symptoms b. The clinical efficacy of antipsychotics is related to their binding at the NMDA receptor. c. Increased cerebral blood volume is characteristic of schizophrenia and its risk states, and related to severity of psychotic symptoms d. Preliminary evidence suggests LY404039 as an effective antipsychotic. e. D‐serine may treat psychotic and other symptoms of schizophrenia. (B) 0 0 5 4. Which of these is NOT evidence in support of glutamate being related to psychosis? a. PCP challenge leads to transient psychotic symptoms b. The clinical efficacy of antipsychotics is related to their binding at the NMDA receptor. c. Increased cerebral blood volume is characteristic of schizophrenia and its risk states, and related to severity of psychotic symptoms d. Preliminary evidence suggests LY404039 as an effective antipsychotic. e. D‐serine may treat psychotic and other symptoms of schizophrenia. 0 0 0 0 0 0 308791817.72540801763534545898 0 0 308621696.60841602087020874023 5 C7375630-F295-4AA0-A4A6-0F18102B39A1-7588-000149A637485763 2. Describe the difference between the concepts of “reward” and “reinforcement” as explanations for continued drug use. See “What drives drug use?” in synopsis. One essential difference is that “reward” refers to an internal state that is hard to specify and hard to compare between humans and laboratory animal models. By contrast, reinforcement is a behavioral quality: a drug is reinforcing if it promotes behavior that leads to further intake of the drug. Such behavior (e.g. lever pressing to obtain drug) can be easily quantified, in both animal and human laboratory studies. Reinforcement has had much more utility in explaining drug addiction and providing insight into its neurobiology than has the concept of reward. 0 0 5 2. Describe the difference between the concepts of “reward” and “reinforcement” as explanations for continued drug use. 0 0 0 0 0 0 308791817.72235602140426635742 0 0 308603260.36738801002502441406 5 E4BEF0B5-9F7E-47B5-A598-05974B6A4BEA-7588-000149A63713B53D 2. Describe primitive reflexes which reemerge when there is frontal damage. The primitive reflexes include the grasp reflex – grasping an object or the examiner’s hand despite being told not to do it.; oral reflexes including suck and root which resemble an infant’s finding the nipple; failure to stop blinking in response to repetitive taps to the forehead. 0 0 5 2. Describe primitive reflexes which reemerge when there is frontal damage. 0 0 0 0 0 0 308791817.71890598535537719727 0 0 308598490.35931998491287231445 5 9115E635-4808-4A69-BA46-424AB41AE45E-7588-000149A63691CE8B 4. What cortical areas are important in the generation of smooth pursuit? Smooth pursuit is triggered by the frontal pursuit area of the frontal eye fields. The motion sensitive areas (V1, MT and MST) are necessary to determine the needed eye velocity. 0 0 5 4. What cortical areas are important in the generation of smooth pursuit? 0 0 0 0 0 0 308791817.71039301156997680664 0 0 308518113.23369699716567993164 5 8A3549A5-F3E4-4187-87D0-5D3E932A4135-7588-000149A6366AC695 3. What is the difference between a forward model and an inverse model? Describe an experiment that might help determine which type of modeling the cerebellum does. Forward models take motor commands and sensory information as input and make predictions about the changes in state or sensory input that will be caused by the motor command. An inverse model computes the motor commands needed to accomplish a desired goal (e.g. sensory state). It was shown that Purkinje cells do not change their firing when a monkey makes the same movement in different force fields. So, even though the needed motor commands were different, the Purkinje cell output was not. Hence Purkinje cell output observed in these experiments would not be suitable for shaping the different motor commands that would be needed to move accurately in the force fields, as would be expected of an inverse model. 0 0 5 3. What is the difference between a forward model and an inverse model? Describe an experiment that might help determine which type of modeling the cerebellum does. 0 0 0 0 0 0 308791817.70783400535583496094 0 0 308517671.97555100917816162109 5 0 5 0 0 0 0 AA163204-5112-4BB4-8C22-A0B082C92FF7-7588-000149A6369B6C3B 0 0 100 41-Vestibular 0 308597097.60401499271392822266 1 5 0281800E-3548-4C96-82BB-D9940989F9CD-7588-000149A637C6075B 4. Gen divided her mice into two groups. In group A she genetically ablated T1R3 receptors, and in group B she ablated T1R2 receptors. She predicted that group A mice will lose sweet and umami sensation but group B will lose only sweet sensation. Is she correct, and why? Gen got it right this time. Sweet sensation depends on dimers [T1R2+T1R3], and umami on dimers [T1R1+T1R3]. So T1R3 is necessary for both taste modalities, while T1R2 is only involved in sweet sensation. 0 0 5 The following question is about Gen and Fran, twin sisters in Themadscientist family. They recently learned about smell and taste and immediately went to the lab to put their knowledge to test. 4. Gen divided her mice into two groups. In group A she genetically ablated T1R3 receptors, and in group B she ablated T1R2 receptors. She predicted that group A mice will lose sweet and umami sensation but group B will lose only sweet sensation. Is she correct, and why? 0 0 0 0 0 0 308791817.73059302568435668945 0 0 308779944.86619502305984497070 5 85DFE23D-DE61-4CBB-A0F8-1EA5A67AC038-7588-000149A636D20861 5. Sleep deprivation takes a toll on our ability to think clearly and on our bodies. Please explain briefly. When we are sleep deprived, we cannot think as quickly or as clearly and we make more errors. Our glucose metabolism changes, thyroid function can be altered, stress hormones are elevated, our immune system is altered and cardiac risk factors are increased. 0 0 5 5. Sleep deprivation takes a toll on our ability to think clearly and on our bodies. Please explain briefly. 0 0 0 0 0 0 308791817.71460098028182983398 0 0 308597578.18258500099182128906 5 0CC8B821-7EFD-470F-A6D0-6E2087C335D4-7588-000149A6375430E9 5. Several brain structures regulate the function of the VTA‐NAcc system. Name two such structures and describe what sort of information they convey to the VTA‐NAcc system. How are the structures you named involved in drug relapse? A number of brain regions are connected to the VTA‐NAcc system and regulate its function in addiction. These areas send information to the VTA‐NAcc system representing the individual’s emotional state, prior experience and current context. The VTA‐NAcc system integrates this data with a drug’s intrinsic reinforcement properties to shape drug‐oriented behavior. Brain areas involved: amygdala, bed nucleus of the stria terminalis (BNST), hippocampus, anterior cingulate, orbitofrontal, dorsolateral prefrontal, and insular cortex. The synopsis describes what type of information each of these structures conveys to the VTA‐ NAcc system, and provides examples of how such areas function selectively during drug relapse under different “trigger” situations. 0 0 5 5. Several brain structures regulate the function of the VTA‐NAcc system. Name two such structures and describe what sort of information they convey to the VTA‐NAcc system. How are the structures you named involved in drug relapse? 0 0 0 0 0 0 308791817.72313201427459716797 0 0 308603306.84745901823043823242 5 C43C009D-3B5B-498B-817F-BC08DD09CEBF-7588-000149A636A731FE 4. What are vestibular and optokinetic nystagmus, and how do they compensate for each other’s deficiencies? Both reduce retinal image motion, but the VOR works when image motion is caused by head movement, while OKN works for any image motion. VOR does not work well at slow rotational frequencies (\u3c000.1 Hz). OKN complements the VOR during these slow rotations. 0 0 5 4. What are vestibular and optokinetic nystagmus, and how do they compensate for each other’s deficiencies? 0 0 0 0 0 0 308791817.71179497241973876953 0 0 308597207.49211198091506958008 5 55C844AE-457C-4645-B5C3-9A303C14378E-7588-000149A636FCAAF1 1. What key pieces of data indicate that the amygdala is important for fear conditioning? Lesions of the amygdala impair the learning and expression of conditioned fear. The key site for learning is thought to be the lateral nucleus where at the level of single neurons information about CSs and USs converge. Indeed, CS responses increase with learning. 0 0 5 1. What key pieces of data indicate that the amygdala is important for fear conditioning? 0 0 0 0 0 0 308791817.71749800443649291992 0 0 308598247.55871999263763427734 5 D31FD211-3578-49AD-BEA4-DCAA9A5A2BEF-7588-000149A636F4C340 2. Does the hypothalamus receive input about body temperature through humoral or neural pathways? What is the evidence that it mediates temperature homeostasis? Does the hypothalamus regulate temperature through humoral or neural pathways? Information about peripheral body temperature is transmitted to the hypothalamus through a neural pathway. However, just changing the temperature within the hypothalamus, e.g. by infusing saline, also alters behavior which changes temperature. Thus changes in both external and internal (hypothalamic) temperature can lead to changes to maintain homeostasis, and the hypothalamus receives this information both through neural pathways (external) and humoral (blood) input (internal). The most direct evidence for the involvement of the hypothalamus in temperature homeostasis is that stimulation of the hypothalamus can lead to behaviors that either increase or decrease body temperature. The hypothalamus uses autonomic and somatic neural pathways to regulate temperature. In addition, the hypothalamus can modulate thyroid function, a longer‐term manipulation which can lead to increased metabolic rate, which also affects body temperature. 0 0 5 2. Does the hypothalamus receive input about body temperature through humoral or neural pathways? What is the evidence that it mediates temperature homeostasis? Does the hypothalamus regulate temperature through humoral or neural pathways? 0 0 0 0 0 0 308791817.71687799692153930664 0 0 308598126.01701599359512329102 5 5EC328C4-F421-4FA0-8FAB-8555A6481057-7588-000149A63615F05B 1. List three differences among reflex, rhythmic, and voluntary movements. Reflex and rhythmic movements are stereotyped, whereas voluntary movements depend on a particular goal and can be changed. Rhythmic movements are cyclical, whereas reflex and voluntary movements generally occur as single instances. Reflex movements are mediated by one or a few spinal synapses, rhythmic movements are largely mediated by local spinal circuits, and voluntary movements require cerebral circuits. 0 0 5 1. List three differences among reflex, rhythmic, and voluntary movements. 0 0 0 0 0 0 308791817.70244300365447998047 0 0 308504134.67964500188827514648 5 F0EB49EF-61E2-4AB2-A87C-C051E81CBAD0-7588-000149A6372D52E7 1. Which of the following drugs would be the first choice to treat a young woman experiencing seizures in which abnormal electrical activity is largely confined to the temporal lobe? A. phenytoin B. phenobarbital C. ethosuximide D. carbamazepine E. gabapentin The correct answer is D. These are partial seizures, so all of the drugs except ethosuximide could be useful. Gabapentin will typically be used as an add‐on rather than a first choice for monotherapy. Carbamazepine is preferable to phenobarbital because it should cause less sedation and has less potential for interactions with other concurrently administered drugs. It is preferable to phenytoin for this particular patient because it does not cause excessive hair growth. 0 0 5 1. Which of the following drugs would be the first choice to treat a young woman experiencing seizures in which abnormal electrical activity is largely confined to the temporal lobe? A. phenytoin B. phenobarbital C. ethosuximide D. carbamazepine E. gabapentin 0 0 0 0 0 0 308791817.72068297863006591797 0 0 308599530.21430397033691406250 5 0 5 0 0 0 0 19C76E05-E277-4718-AEFA-5917E4F00F49-7588-000149A6362A3129 0 0 100 31-MotUnit 0 308504294.36016201972961425781 1 5 C896DCD4-9C0B-4B79-9368-F1DE050F7CCD-7588-000149A63689CA29 2. Describe the two different neuronal types in the abducens nucleus. Abducens motor neurons project desired eye position and velocity to the lateral rectus muscle. Abducens interneurons project the identical signals to the medial rectus motor neurons in the oculomotor nucleus in the midbrain. Their axons travel in the medial longitudinal fasciculus. 0 0 5 2. Describe the two different neuronal types in the abducens nucleus. 0 0 0 0 0 0 308791817.70986998081207275391 0 0 308518081.19414097070693969727 5 54C2EAA2-53E3-46B9-8E6D-97FDEC73C222-7588-000149A636D5F89E 6. Sleep walking behaviors can occur out of non‐REM sleep and out of REM sleep. Briefly explain. Classical somnambulism of childhood occurs out of non‐REM sleep and usually out of deep sleep, stage 3. REM sleep behavior disorder occurs out of REM sleep and is a disorder of the elderly. 0 0 5 6. Sleep walking behaviors can occur out of non‐REM sleep and out of REM sleep. Briefly explain. 0 0 0 0 0 0 308791817.71485900878906250000 0 0 308597587.85741901397705078125 5 8B0CDA49-60C4-4411-B4D2-2986B7AC8DF4-7588-000149A636E75883 4. “Parasympathetic and sympathetic inputs to the bladder have opposite effects on bladder emptying because parasympathetic input contracts, while sympathetic input relaxes, muscles of the bladder.” This is not an entirely true statement. Which part(s) is(are) true and which false? Explain. It is true that they have opposite effects, with parasympathetic activity promoting bladder emptying and sympathetic activity inhibiting it. While parasympathetic activity does contract the detrusor muscle, it also relaxes the internal sphincter. Sympathetic activity has the opposite effects on those muscles. 0 0 5 4. “Parasympathetic and sympathetic inputs to the bladder have opposite effects on bladder emptying because parasympathetic input contracts, while sympathetic input relaxes, muscles of the bladder.” This is not an entirely true statement. Which part(s) is(are) true and which false? Explain. 0 0 0 0 0 0 308791817.71600002050399780273 0 0 308597780.76172399520874023438 5 016B5537-139F-4BB7-BC60-BAC00A0765B3-7588-000149A63672A5DE 1. What are the four main nuclei of the basal ganglia? striatum, globus pallidus, subthalamic nucleus, substantia nigra 0 0 5 1. What are the four main nuclei of the basal ganglia? 0 0 0 0 0 0 308791817.70844697952270507812 0 0 308517803.39809602499008178711 5 0 5 0 0 0 0 225BE78B-2303-4734-9A0B-859FB8D53531-7588-000149A63759D32E 0 0 100 57-AntiD 0 308620139.20091700553894042969 1 5 16560A51-1DFE-4458-84B5-E0EC02E9F91E-7588-000149A636DF7B0A 2. Orthostatic hypotension is a large drop in blood pressure upon standing from a supine position, resulting in faintness. It is caused by gravity‐induced pooling of blood in the lower part of the body, which reduces venous return to the heart and, thereby, cardiac output. Usually, these physiological changes are rapidly compensated for by actions of the baroreceptor reflex. Orthostatic hypotension is a common symptom of pure autonomic failure. Would you expect diminished sympathetic or parasympathetic functioning to be more important in causing orthostatic hypotension? Why? Probably the diminished sympathetic functioning is more important. Sympathetic input to the heart increases cardiac output by affecting the force as well as the rate of contraction, while the parasympathetic system basically only affects rate. Also, the sympathetic system can increase blood pressure by causing vasoconstriction, whereas the parasympathetic system has relatively little direct effect on blood vessels. 0 0 5 2. Orthostatic hypotension is a large drop in blood pressure upon standing from a supine position, resulting in faintness. It is caused by gravity‐induced pooling of blood in the lower part of the body, which reduces venous return to the heart and, thereby, cardiac output. Usually, these physiological changes are rapidly compensated for by actions of the baroreceptor reflex. Orthostatic hypotension is a common symptom of pure autonomic failure. Would you expect diminished sympathetic or parasympathetic functioning to be more important in causing orthostatic hypotension? Why? 0 0 0 0 0 0 308791817.71548300981521606445 0 0 308597758.38252198696136474609 5 9354C313-BFC6-4D0F-ABB4-46DC850CD55C-7588-000149A6369F3D2F 2. What are the different functions of canals and otolith organs? Canals detect angular (rotational) acceleration. Otoliths detect linear acceleration and gravity. 0 0 5 2. What are the different functions of canals and otolith organs? 0 0 0 0 0 0 308791817.71127402782440185547 0 0 308597188.98785299062728881836 5 6142821E-99ED-4AA2-8AF5-39EC08D6A331-7588-000149A636841990 1. What are the signals which drive the vestibuloocular reflex, smooth pursuit, and saccades? The VOR is driven by head velocity, smooth pursuit is driven by target velocity, and saccades are driven by the position of the desired target. 0 0 5 1. What are the signals which drive the vestibuloocular reflex, smooth pursuit, and saccades? 0 0 0 0 0 0 308791817.70959597826004028320 0 0 308518029.68045502901077270508 5 23FC1101-00FC-41E7-922A-576F56EF79A3-7588-000149A637CDEE4F 6. Fran wants to create mice that perceive a normally tasteless substance (substance X) as being sweet. Can she do this and if so, how? If she can do it, what does this say about taste coding? Finally, if she could do it, what would she have to worry about with the altered mice? Fran can succeed. She has to co‐express a receptor for substance X in taste cells that carry T1 receptors. By activating T1‐containing cells, the substance‐X receptor will elicit a sweet sensation and approach behavior. This is strong evidence that a taste sensation is determined by a cell type and not by a particular receptor. Fran will have to be careful about the metabolic effects of substance X: the mice will ingest this substance whenever given the chance and may overdo it if their bodies do not have the appropriate feedback mechanisms for regulating its intake. 0 0 5 The following question is about Gen and Fran, twin sisters in Themadscientist family. They recently learned about smell and taste and immediately went to the lab to put their knowledge to test. 6. Fran wants to create mice that perceive a normally tasteless substance (substance X) as being sweet. Can she do this and if so, how? If she can do it, what does this say about taste coding? Finally, if she could do it, what would she have to worry about with the altered mice? 0 0 0 0 0 0 308791817.73110997676849365234 0 0 308779982.60130798816680908203 5 02243BD6-BB77-4C69-8F07-02EBAC1820C0-7588-000149A636592738 4. Describe the half‐center model of locomotion. The half‐center model involves reciprocal inhibition between an interneuron that excites a flexor motor neuron on the ipsilateral (stimulated) side and an interneuron that excites an extensor motor neuron. Stimulation of flexor reflex afferents excites the flexor interneuron, which excites the flexor motor neuron and inhibits the extensor interneuron, reducing the drive on the extensor motor neuron. This inhibition fatigues, allowing the extensor interneuron to fire, exciting the extensor motor neuron and inhibiting the flexor interneuron. The flexor and extensor “half‐centers” alternate activity, producing alternating flexion and extension. 0 0 5 4. Describe the half‐center model of locomotion. 0 0 0 0 0 0 308791817.70668500661849975586 0 0 308517282.56157797574996948242 5 0 5 0 0 0 0 7FDA5579-750A-4C1E-B1D6-7D33B0B6D29D-7588-000149A637447705 0 0 100 51-NeurobioAddict 0 308603188.34877300262451171875 1 5 957B5F62-314D-43B4-B602-359295145D2D-7588-000149A636361C1D 4. What is the main function of the Renshaw cell? Renshaw cells are inhibitory interneurons that receive excitatory synaptic inputs from motor neuron axon collaterals. Renshaw cells send their axons back to motor neurons to inhibit them and hence provide a negative feedback pathway which is thought to regulate motor neuron firing. 0 0 5 4. What is the main function of the Renshaw cell? 0 0 0 0 0 0 308791817.70438498258590698242 0 0 308504774.18149101734161376953 5 3BF530C0-B955-4C2F-851E-2A944D3217D3-7588-000149A637A6F2D8 3. Based on what you heard in the lecture, is it likely that neuroligin is important in establishing the topographical segregation of excitatory from inhibitory synapses on CNS neurons? No. Restriction of excitatory synapses to dendritic spines, where few inhibitory synapses are found, probably results to a considerable degree from the formation of stable contacts between postsynaptic filopodia and glutamatergic, but not GABAergic, axons. The filopodia probably transform into spines. Neuroligin does not seem to be important for the formation of the initial contact, but rather for the maturation of the synapse. 0 0 5 3. Based on what you heard in the lecture, is it likely that neuroligin is important in establishing the topographical segregation of excitatory from inhibitory synapses on CNS neurons? 0 0 0 0 0 0 308791817.72855502367019653320 0 0 308777771.27701199054718017578 5 0 5 0 0 0 0 B4B5A802-EE59-41D1-A56C-005099D71F7A-7588-000149A636B4D881 0 0 100 42-BrainStem 0 308597346.29203397035598754883 1 5 07A5C34E-CEE4-40B8-86E7-FFF959ACBD6B-7588-000149A637B48E6E 2. What is a feature of the NMDA receptor that allows it to play a key role in L‐LTP? It is highly permeable to Ca++; influx of Ca++ leads to elevation of cAMP. The fact that, to open, the NMDA receptor channel requires depolarization (to expel Mg++ from the channel) as well as the binding of glutamate renders it particularly useful as a mediator of the synaptic plasticity underlying associative learning. 0 0 5 2. What is a feature of the NMDA receptor that allows it to play a key role in L‐LTP? 0 0 0 0 0 0 308791817.72944700717926025391 0 0 308777822.56559902429580688477 5 F7292B89-01BD-4D01-B735-0B95B7AFA9FE-7588-000149A637B88431 1. How does the problem of sensory transduction differ for olfaction vs. vision? To encode light, peripheral receptors have to be sensitive to a small number of primary attributes including wavelength and location. In contrast, the set of odorants has no simple classification. Odorants differ greatly in chemical composition (molecular composition, size, solubility) and are not easy to categorize: compounds with different structures elicit similar odors and those with similar structures can elicit very different odors. Thus odorant coding relies on a large number of odorant receptors and combinatorial coding. 0 0 5 1. How does the problem of sensory transduction differ for olfaction vs. vision? 0 0 0 0 0 0 308791817.72980898618698120117 0 0 308779825.03304600715637207031 5 8B8FE613-EA57-471B-94FE-C248DE9B1863-7588-000149A63791A135 3. An experiment is performed in which the eyeball of a frog is rotated 180° in its socket and the retinal axons are allowed to regrow into the optic tectum. However, before the regenerating axons arrive in the tectum, an antibody is applied which blocks the functioning of ephrins throughout the optic tectum except close to the anterior pole. Retinal axons originating from what is now the anterior half of the retina will A. form synapses in the anterior half of the optic tectum. B. form synapses in the posterior, as well as the anterior, half of the optic tectum. C. form synapses in the posterior, as well as the anterior, half of the optic tectum, but then the axons innervating the posterior half will die as their parent cells undergo apoptosis. D. be unable to grow into the optic tectum. The correct answer is B. Rotation of the eyeball means that neurons that were originally in the posterior half of the retina are now in the anterior half. The axons of those neurons now at the anterior pole express the most eph kinase on their growth cones and will stop growing at the anterior pole of the tectum, because enough growth inhibitory signal is generated even with the relatively low levels of ephrin expression at that place in the tectum. Other axons from the anterior half of the retina would be expected to stop growing somewhere in the anterior half of the tectum, where ephrin levels are high enough to generate sufficient inhibitory signal. But, with ephrin functioning blocked, these axons should continue to grow, invading the posterior half of the tectum. 0 0 5 3. An experiment is performed in which the eyeball of a frog is rotated 180° in its socket and the retinal axons are allowed to regrow into the optic tectum. However, before the regenerating axons arrive in the tectum, an antibody is applied which blocks the functioning of ephrins throughout the optic tectum except close to the anterior pole. Retinal axons originating from what is now the anterior half of the retina will A. form synapses in the anterior half of the optic tectum. B. form synapses in the posterior, as well as the anterior, half of the optic tectum. C. form synapses in the posterior, as well as the anterior, half of the optic tectum, but then the axons innervating the posterior half will die as their parent cells undergo apoptosis. D. be unable to grow into the optic tectum. 0 0 0 0 0 0 308791817.72715801000595092773 0 0 308667684.04659402370452880859 5 C7A19FD6-A37F-499C-B7AE-08428F4D36A8-7588-000149A636AB2C0D 5. What are the vestibulospinal and vestibulocolic reflexes? The vestibulocolic reflex keeps the head still in space or on a level plane when you walk. The vestibulospinal reflex adjusts posture for rapid changes in position. 0 0 5 5. What are the vestibulospinal and vestibulocolic reflexes? 0 0 0 0 0 0 308791817.71205502748489379883 0 0 308597226.25660699605941772461 5 071F5330-67FA-4D0A-BF66-23E8568D30DD-7588-000149A637C20EF9 3. Fran Themadscientist adopted a more sophisticated technique, genetically ablating 4 of the 30 types of T2 receptors in her mice. She predicted that the mice will lose the ability to taste quinine but will detect all other bitter substances normally. Is she correct, and why? Fran is also incorrect. T2 receptors code bitter taste combinatorially, meaning that the 4 T2 receptors she ablated participated in the coding of multiple substances, not just quinine. 0 0 5 The following question is about Gen and Fran, twin sisters in Themadscientist family. They recently learned about smell and taste and immediately went to the lab to put their knowledge to test. 3. Fran Themadscientist adopted a more sophisticated technique, genetically ablating 4 of the 30 types of T2 receptors in her mice. She predicted that the mice will lose the ability to taste quinine but will detect all other bitter substances normally. Is she correct, and why? 0 0 0 0 0 0 308791817.73033398389816284180 0 0 308779906.43168598413467407227 D2E810F6-B907-4C62-81A2-279D7830C53A-7588-000149A637D6A12D 50 0 50 NS_Q\u2600A2 0 308504037.64058399200439453125 1 5 26A2B197-41D5-475D-BB55-32944CF0EA6F-7588-000149A636EF4F9A 1. How does leptin affect anabolic and catabolic pathways in the brain? Is it secreted in response to satiety or adiposity? Leptin is secreted by fat cells and is considered an adiposity signal. Leptin has opposite effects on the anabolic and catabolic pathways in the hypothalamus. Catabolic and anabolic pathways are distinct within the hypothalamus and leptin, through a multi‐ step process, increases catabolic activity and decreases anabolic activity. This means increasing energy expenditure and decreasing food intake. Some evidence indicates that the sensitivity of the catabolic and anabolic pathways to leptin may play a role in determining one’s biological set point for body weight. 0 0 5 1. How does leptin affect anabolic and catabolic pathways in the brain? Is it secreted in response to satiety or adiposity? 0 0 0 0 0 0 308791817.71661800146102905273 0 0 308598117.11519098281860351562 5 114AF0EE-BBAE-45C0-A3D0-0BF42B68BC58-7588-000149A6379D7CD5 1. Give an example of one cue released from the motor neuron terminal that positively affects the development of the postsynaptic side of the NMJ and one that negatively affects it. Both cues are released from the terminal, yet positive effects predominate close to the terminal and negative effects predominate away from the terminal. Why? Agrin is a positive cue and acetylcholine is a negative cue. The positive cue is stronger than the negative cue. However, it signals only locally, through the MuSK signaling complexes that form at the site of agrin binding. Acetylcholine is converted into an electrical signal which spreads all along the muscle cell. Away from the terminal, this negative signal is unopposed by the positive signal. 0 0 5 1. Give an example of one cue released from the motor neuron terminal that positively affects the development of the postsynaptic side of the NMJ and one that negatively affects it. Both cues are released from the terminal, yet positive effects predominate close to the terminal and negative effects predominate away from the terminal. Why? 0 0 0 0 0 0 308791817.72803401947021484375 0 0 308777745.77911400794982910156 5 ED407E7B-79A6-48BC-AC53-39F81344807F-7588-000149A63717CBA6 3. Describe the deficit caused by bilateral medial temporal lobe damage. Patients with bilateral medial temporal lobe deficits lose the ability to lay down new declarative memory, although they have some ability to learn motor tasks. 0 0 5 3. Describe the deficit caused by bilateral medial temporal lobe damage. 0 0 0 0 0 0 308791817.71917498111724853516 0 0 308598556.69103199243545532227 5 0 5 0 0 0 0 E960404B-BC00-4E0D-A25C-7EB618CE52A9-7588-000149A6370FE82B 0 0 100 47-CerebralCortex 0 308598370.92610597610473632812 1 5 CB4B6D41-7F55-474B-ACE6-B895C9245ABC-7588-000149A63732C751 2. A patient has only recently started having seizures, for which you will prescribe phenytoin. Would you expect to initially see a problem with dose‐dependent elimination? Why? You would not expect to see a problem initially because you would start with a relatively low dose of phenytoin and dose‐dependent elimination only becomes a problem at higher doses. You would progressively increase the dose of phenytoin if the initial doses were not satisfactory. 0 0 5 2. A patient has only recently started having seizures, for which you will prescribe phenytoin. Would you expect to initially see a problem with dose‐dependent elimination? Why? 0 0 0 0 0 0 308791817.72094297409057617188 0 0 308599571.55084902048110961914 5 C6C11D4B-C7D3-4BA2-8DEF-33F0CFBE155C-7588-000149A6362DFF83 2. If two motor neurons of different cell body size receive the same excitatory synaptic input, which is likely to produce an action potential first as the input increases? Why? If the motor neurons have similar resting potentials, the smaller motor neuron will reach its firing threshold first. This is due to its higher input resistance. The resistance of the cell is inversely proportional to the size of its cell body. That is, the smaller the cell body size the higher the resistance, and according to Ohm's Law the same synaptic current will result in a larger excitatory postsynaptic potential in the smaller neuron and hence it will be more likely to reach its firing threshold and elicit an action potential. 0 0 5 2. If two motor neurons of different cell body size receive the same excitatory synaptic input, which is likely to produce an action potential first as the input increases? Why? 0 0 0 0 0 0 308791817.70385700464248657227 0 0 308504746.57584601640701293945 5 661E8236-26AB-4196-A9F5-B79810C7C9AA-7588-000149A6362082BC 3. What do these two psychophysical principles tell us about motor control: motor equivalence and the speed‐accuracy trade‐off? Motor equivalence suggests that the brain has abstract representations of movements (motor programs), not just commands specific to each joint or muscles. The speed‐accuracy trade‐off suggests that the motor system must handle the effects of its own variability when selecting how fast to move. 0 0 5 3. What do these two psychophysical principles tell us about motor control: motor equivalence and the speed‐accuracy trade‐off? 0 0 0 0 0 0 308791817.70296901464462280273 0 0 308504206.94399899244308471680 5 A19114EA-FF60-4781-B60B-610002B2B24E-7588-000149A636247D88 4. How is the distinction between control of axial and of distal (limb) muscles reflected in anatomical pathways? List these differences for spinal neurons, descending brain stem pathways and the corticospinal tract. Neurons and axons related to the control of axial musculature generally reside or travel along more medial pathways than those related to distal (limb) muscles. For spinal neurons, this distinction corresponds to the ventromedial vs. dorsolateral nuclei. For pathways that originate in the brainstem, the distinction is between medial (vestibulospinal, reticulospinal, tectospinal tracts) and lateral (rubrospinal) pathways. For the corticospinal tract, the distinction is between ventral and lateral corticospinal tracts. 0 0 5 4. How is the distinction between control of axial and of distal (limb) muscles reflected in anatomical pathways? List these differences for spinal neurons, descending brain stem pathways and the corticospinal tract. 0 0 0 0 0 0 308791817.70323097705841064453 0 0 308504249.57255798578262329102 5 2EE4FDB6-13AC-4AA5-94C9-A50B5F0FE3E4-7588-000149A636F8B7BF 3. What is the evidence that leptin may be involved in determining biological set points for body weight? In leptin‐deficient mice, it has been shown that there are changes in the number and strength of excitatory and inhibitory synapses in the hypothalamic feeding circuitry, with the projections from the arcuate nucleus to the PVN particularly affected. Restoring leptin can restore the growth of these projections. 0 0 5 3. What is the evidence that leptin may be involved in determining biological set points for body weight? 0 0 0 0 0 0 308791817.71713602542877197266 0 0 308598142.42943197488784790039