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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?
4. What cell, a well-known cell type, is the output to the deep cerebellar
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
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
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
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
the mRNA is active in, and the protein laid down by, the mother, not the
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
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
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?
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?
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
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
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)?
40. How can one side of the brain be anesthetized to study laterality of
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?
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
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
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)
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