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BIOL 415 Nerve cell mechanisms in behavior
Test 2 Thursday May 10, 2018 ­p; Prof. Stark
All questions are short answer. 65 points total

1. Why would motor control of the lower part of the face be more susceptible to nerve damage than the upper part?

not bilaterally innervated

2. "In a sense, Huntington's is the opposite of Parkinson's." Rationalize this statement on the basis of either (1) thalamic input to cortex, or (2) behavior of the afflicted person.

excitatory input to cortex is lower in Parkinson's, explaining hypokinesia, higher in Huntington's explaining choreo-athetosis

3. Which nerve innervates more than one extraocular muscle?

occulomotor (III)

4. What cell, a well-known cell type, is the output to the deep cerebellar nuclei?


5. "The thalamus is a major motor relay station." Justify this statement when the pyramidal motor system does not synapse in the thalamus.

extrapyramidal system feeds back to cortex via thalamus

6. "Polyglutamine repeat." Translate.

glutamine is an amino acid. polyglutamine repeat is a string of them, with a low number in normals and a high number in Huntington's

7. What part of the brain is especially altered in the ataxic weaver mouse mutant?


8. "Inside the larva are these pieces of tissue that are determined to become adult structures but are not yet differentiated. Say something about them (e.g., What are they called? When do they differentiate?).

imaginal disks have cell proliferation in larvae then they differentiate into adult structures in the pupa case

9. What is the function of the protein that is abnormal in Huntington's disease?

unknown, but interacts with many proteins and is toxic when mutated

10. What parts of the brain are most affected in Huntington's disease's motor abnormalities?


11. Give a cause of death in Huntington's disease.

falls, accidents, suicide, pneumonia, heart disease

12. Sevenless is a receptor tyrosine kinase. Name another protein in the sevenless signal transduction pathway.

boss, downstream of receptor kinase, sos, ras, MAP kinase,

13. Why are the first genes to guide Drosophila embryology referred to as "maternal genes?"

the mRNA is active in, and the protein laid down by, the mother, not the zygote

14. Ligands such as shh, RA, FGF, BMP and Wnt eventually control transcrption. Name one receptor corresponding to any of these ligands.

patched, retinoic acid binding protein, receptor tyrosine kinase, receptor serine kinase, frizzled

15. The genes involved in homeotic mutants-- answer either (1) What shape is the critical domain of the protein they encode? or (2) What is the function of that protein?

helix turn helix, bind DNA to activate transcription

16. In addition to nuclear receptors for estrogen in the brainANSWER EITHER (1) Where else are estrogen receptors? OR (2) What is the molecular nature of these other estrogen receptors?

membrane, G-protein coupled

17. In embryonic neural precursor cells, what is enhanced with estrogen treatment?

neurite outgrowth

18. In adult synapses, increased estrogen levels during the cycle apparently increase what structural specialization?


19. Dogma has it that there is no regeneration of neurons in the mammalian central nervous system. Describe how post-mitotic cells exit from the cell cycle.

arrest in G1

20. In between ectoderm and the neural groove are cells whose fate is very different from those of the neural groove. In what way?

neural crest will become components of peripheral n.s.

21. The optic vesicle, an outpocket of the diencephalon, eventually forms the retina. What do these induce the overlying ectoderm to form?

lens and anterior portion of eye

22. Rotating the frog eye up-side-down gives opposite results if done in the adult vs. a few days before Harrison stage 28. What is the behavior in the adult after EARLY rotation?

animal will flick its tongue (to catch an insect) in the correct direction

23. Filopodia protrude from what important structural specialization in axon path finding?

growth cone

24. The conventional wisdom (until recently) was that neurogenesis did not occur in the adult brain. Then what does mediate most of the structural and functional neuroplasticity in the adult brain?


25. What particular ion is proposed to interact with a kinase in mediating long term potentiation?

26. For the above, ANSWER EITHER (1) What neurotransmitter is involved? OR (2) What neurotransmitter receptor is involved?

glutamate NMDA

27. Why is habituation of the gill withdrawal considered to be a simple model of learning instead of sensory adaptation or muscle fatigue?

it is change in synapse, not sensory receptor or muscle

28. Even though it has been over 50 years since his famous textbook, Donald Hebb is still mentioned frequently in neuroscience. In what context?

reverberating circuits of excitation for short term memory

29. How does transcription of ubiquitin hydrolase promote long -erm sensitization?

breaks down regulatory (inhibitory) subunits of PKA

30. A Schaffer collateral is stimulated to "tetanus" to show long-term potentiation at the synapse with a CA1 pyramidal neuron. What is the control for this experiment?

another collateral is not prestimulated but it is tested (and shows no LTP)

31. Why did RP, our hemispatial neglect syndrome subject, think it was important to relate his experience with pulmonary embolism?

clots cause stroke and p.e.

32. Following up on that last question, when would a previously healthy person be most at risk for a pulmonary embolism?

after sitting still like when on an overseas flight

33. Why does RP and his friend who also had a stroke need to be very careful walking?

because the foot tends to drop, it is easy to trip; might not be able to stand back up; always thinking about what (s)he might crash into when falling

34. A subject stares at a fixation point in front of his or her nose. An object to the right of the fixation point is displayed. Say why the subject can (or cannot) say what is seen.

right visual field = left retinal field, goes to left hemisphere the side with language

35. In a subject with a severed corpus callosum, can the right hemisphere "know" what stimulus was presented to it?

yes but it cannot say

36. Describe the performance on the cancel the line task in a patient with hemispatial (contralateral) neglect syndrome.

turns ­p; to x only on the right side of the figure

37. Washoe, Sarah and Nim Chimsky were all used in a study of what capability?

language in chimps

38. Compared with stage 4 sleep ANSWER EITHER (1) What is the amplitude of the EEG in wakefulness (and REM sleep)?... OR (2) What is the frequency of the EEG in wakefulness (and REM sleep)?

low amplitude, high frequency

39. Which stage of sleep is accompanied by atonia (muscle paralysis)?

rem sleep

40. How can one side of the brain be anesthetized to study laterality of language?

circle of Willis notwithstanding, barbituate to one internal carotid goes preferentially to one side of the brain

41. When (in terms of sleep stage) does most dreaming occur?

rem sleep

42. A person put in the constant darkness after having been in a light-dark cycle of 12 hr on - 12 hr off will have an activity cycle that is not exactly 24 hr. Give details.

would go to >24 hrs, sleep in on Saturday morning

43. "It is like a sympathetic ganglion in the brain." Answer either (1) Why? Or (2) What structure?

puts out norepinephrine, locus coeruleus

44. What is cryptochrome used for?

blue light receptor interacts with other proteins for circadian rhythm

45. Very recent literature demonstrated that mice lacking rod and cone photoreceptors are blind but they still could be entrained to a photoperiod. What is the photoreceptor (pigment and cell type)?

melanopsin ganglion cells

46. Describe the situation for declarative vs nondeclarative memory for patient HM with the hippocampal lesion.

could not form new memories but could pick up skills

47. In addition to tangles of tau, what is another organic brain problem in Alzheimers disease?

beta-amyloid plaques (also nerve cell damage and death)

48. Why did the memory presentation focus on autobiography on several subjects?

they have highly superior autobiographical memory

49. Why is a rat's performance in the radial 8-arm maze considered an example of "working memory?"

each time, it must remember which of the arms it has already visited

50. Storage oscilloscope fragments were sprinkled on a regular oscilloscope. The entire physiology department at Yale wrote this spoof to criticize what published "finding?"

that RNA from a flat worm that had "learned" (or cannibalism) could transfer the memory

51. Money's attempt to demonstrate that upbringing predominated over chromosomal makeup in gender identity backfired. How?

boy surgically changed to girl was never adjusted

52. What differences did Simon LeVay find among men in the interstitial nucleus of the anterior hypothalamus?

homosexual vs heterosexual men differ, the homosexual males have a higher cell count and volume, resembling those of women

53. Name at least one of the substances in early male development contributing to sexual dimorphism.

testicular determining factor, testosterone, Mullerian Inhibiting Factor

54. In the rod, rhodopsin activates transducin which activates phosphodiesterase which affects a cGMP gated channel. In Drosophila, say something about EITHER (1) the enzyme used instead of phosphodiesterase OR (2) the name or property of the channel.

phospholipase, transient receptor potential

55. With a technique as crude as the ERG (electroretinogram), how is it possible to make conclusions about the specific properties of R1-6, R7 and R8 when the electrode records the responses of all of those receptors?

mutants like sevenless and rdgB, the latter eliminating R1-6 systematically simplify the retina

56. In Drosophila, autophagy via coated vesicles, multivesicular bodies and lysosomes characterizes turnover of photoreceptive membrane. Say something about how turnover in vertebrate photoreceptors is handled.

tips of rods are shed, phagocytosed by pigment epithelium, undigested turns to lipofuscin, new disks are made at base of rod

57. People and flies get vitamin A (and other important molecules) through dietary carotenoids. Name one.

beta carotene, lutein, zeaxanthin

58. What visual capability do Drosophila and people missing a lens have (that you do not have)?

sensitivity to ultraviolet light

59. Under what circumstances would a rat give itself electrical stimulation of the brain?

electrode in hypothalamus, stimulation is reinforcement (reward), will press bar in Skinner box

60. Why would paralysis be a more likely consequence of stroke in the lower portion of the face than in the upper portion?

upper is bilaterally innervated, lower is not

61. A graduate of a neuroscience course is required to be able to say who Phineas Gage was.

a guy who had a spike blown through his brain and acted strangely after that

62. "If you put the position and momentum of every particle in the universe into a big computer, you should be able to predict all events." What scientific principle says this is not possible?

the Heisenberg uncertainty principle

63. According to Sperry, why MIGHT one think that "real mental freedom to act and choose is only an illusion?"

"materialistic science holds that a complete explanation of brain function is possible in purely objective physiological and biophysical terms."

64. In rationalizing free will, what relationship does Nobelist Sperry assign to physical laws vs emergent properties?

physical laws still operate, but emergent properties outclass (supercede) them

65. Explain, in terms of the general interpretation of Lloyd Morgan's cannon, where he stood on the materialist vs mentalist dichotomy.

he was mechanistic and did not feel the need to invoke an animal's mental capacity to explain its behavior

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last revised 4/2/18