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BIOL 415 Nerve cell mechanisms in behavior
Final exam Thursday May 5, 2016 ­p; Prof. Stark
All questions are short answer. 65 points total

1. For either the t-tubule or the sarcoplasmic reticulum, give the pharmacological name for the calcium channel.

dihydropyridine receptor, ryanodine receptor

2. How is it that stretch in the bicep would lead to inhibition in the tricep?

there is an inhibitory interneuron in the reflex arc

3. In one figure, the axon of the alpha motor neuron is shown connecting to "extrafusal" muscle fibers. ANSWER EITHER (1) What other type of efferent motor neuron is shown? (2) What type of muscle do these other nerves innervate? OR (3) What is the name of the compartment that houses these other muscles?

gamma motor neuron, intrafusal muscle cells, muscle spindles

4. Say something about mototopic organization of motor neurons in the ventral horn.

proximal muscles are medial, flexors are dorsal

5. There is a lumbar enlargement in the spinal cord. ANSWER EITHER (1) What is the other enlargement? OR (2) What makes the spinal cord larger in these two areas?

cervical, more motor neurons for limbs

6. What cells are affected by ALS (Lou Gehrig's disease)?

spinal motor neurons

7. Where are the cells that form the lateral and medial tracts of the pyramidal motor system?

precentral gyrus

8. What is a major difference in how the primary motor cortex vs the cingulate motor area innervates the face?

lower face from primary motor cortex is contralateral, upper face from cingulate is bilateral

9. Cerebral cortex, red nucleus, superior colliculus and reticular formation. What brain nucleus is missing from this list of structures that send innervation to the spinal motor neurons?

vestibular nucleus

10. The basal ganglia do not send a tract down the spinal cord. How, then, do they exert their motor control?

via thalamus and motor cortex

11. For extrapyramidal motor control, the substantia nigra and the pars compacta feed to the caudate and the putamen. What other major brain area feeds to the caudate and putamen for monitoring?

cerebral cortex

12. In a block diagram for Parkinson's disease, there are arrows. For instance, a small arrow with a minus sign indicates diminished inhibition of the subthalamic nucleus from the external segment of the globus pallidus. In this whole cascade, only one change is primary, all the others are consequences. What is that primary defect?

decreased dopamine from substantia nigra to caudate and putamen

13. What do we mean by "genetic anticipation" for the triplet repeat diseases?

they can get worse from generation to generation, more triplet repeats

14. In Huntington's disease ANSWER EITHER (1) In what direction is the input from the thalamus to the cortex affected? OR (2) Is this input excitatory or inhibitory?

increased, excitation

15. The superior cerebellar peduncle (brachium conjunctivum) carries information from deep cerebellar nuclei to (where?).

vl complex (thalamus)

17. What is inside a Drosophila larva that becomes adult structures?

imaginal discs

18. Why was it so politically controversial to use embryonic stem cells in human therapy?

embryos must be created and destroyed

19. Mutants like antennapedia (that puts legs where the antennae should be) or bithorax (that puts a second thoracic segment with wings next to the normal one) are called (what?).

homeotic mutants

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

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

21. Give one of the fates of neural crest.

sensory ganglia, autonomic ganglia, adrenal medulla, non-neural cells like melanocytes

22. "CNS neurons do not regenerate by mitosis." This was said in the very first lecture. At what stage in the cell cycle do neuroblasts become postmitotic?

they are arrested in G1

23. Embryologists tell us that the retina and optic "nerve" are part of the central nervous system. You were told that earlier in this course too. Now add some details that justify that position.

optic vesicle becomes optic cup, outpocket from diencephalon

24. If you tried Sperry's experiment, turning the eye up-side-down and letting it reconnect to the tectum, before stage 28, how would the frog respond to a moving fly presented to the side of its visual field?

it would flick its tongue to the correct place

25. Agrin and its receptor does (what?) in the development of (what model of the synapse?).

it is involved in gathering the nicotinic receptors to the end plate of the neuromuscular junction

26. What finding led to the conclusion that apoptosis reduced the number of spinal motor neurons to the right number to innervate a limb?

there were enough precursors of cells to innervate two limb buds

27. Brain-derived neurotrophic factor (BDNF), neurotrophin-3 (NT-3), and neurotrophins 4 and 5 (NT-4/5). What is missing from this list of neurotrophins?

nerve growth factor

28. "Potentiating GABA inhibition with diazepam widens columns." Why was this statement offered in the context of cellular bases of learning?

applies to the (re) establishment of ocular dominance columns

29. Why do they call classical (Pavlovian) and operant (instrumental) conditioning "associative learning?"

stimulus and response are paired repeatedly

30. What is the modification of PKA that characterizes the difference between short term sensitization and long term sensitization?

ubiquitin hydrolase breaks down regulatory (inhibitory) subunits, making the activation persistent.

31. The fruit fly Drosophila is given electrical shock repeatedly in the presence of a specific odor, and it learns to avoid the area where that odor is present. Eventually, it was found that the cAMP signal transduction pathway was important in this learning. What strategy allowed them to make this conclusion?

obtain mutants with learning defects

32. Draw or describe the bisect the line task for a patient with hemispatial (contralateral) neglect syndrome.

the line is definitely not cut in half

33. 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.

34. 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

35. 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 in to when falling

36. Describe or draw how the neglect syndrome patient would do on a cancel the line test.

a lot of little dashes are turned into x's only on the right side of the page

37. Patients with damage to what brain area have difficulty with the line bisection task?

parietal, temporal, frontal, superior occipitofrontal fasciculus

38. "After a train of stimuli to axons of CA3 pyramidal axons (Schaffer collaterals) the response of the postsynaptic cell (CA1 pyramidal neuron) is larger." Answer either (1) What is this simple kind of learning called? or (2) What part of the brain was being studied?

long term (lasting) potentiation, hippocampus

39. If excitation of the climbing fiber and the parallel fiber are paired, there is a decrease in the effectiveness of the glutaminergic AMPA receptor. Answer either (1) What is the postsynaptic cell? or (2) What is this simple model of learning called?

purkinje cell, long term depression

40. What do you do to present a visual stimulus to only the left cerebral cortex in a patient whose corpus callosum has been severed?

right visual field (keep eye fixation) crosses (for both eyes) since optic chiasm is not severed

41. Chimps cannot speak. Why did some researchers believe that they did, however, have some rudiments of language?

with sign language or a key board of symbols, they can communicate

42. What is the evidence that language is localized on the left side of the brain even in left-handed people?

wada procedure, anesthetize one side of the brain by injection into one carotid

43. What place in the brain has photoreceptors that are important in entraining circadian rhythms in vertebrates with small heads?

pineal

44. "PGO" spikes at the onset of REM. Say what ONE of the letters (PGO) stands for.

pontine, geniculate, occipital

45. During the work week, your rhythm is entrained by light and other cues, and it is 24 hours. Give one of the expressions describing your rhythm if the zeitgeber is removed.

you are free-running, your biological clock is endogenous, your rhythm is about a day (circadian), your rhythm is longer than 24 hours

46. How is the superior cervical ganglion of the sympathetic chain related to biological rhythms in humans?

it is on the pathway from the hypothalamus to the pineal

47. For mice OR for Drosophila, state the name of a visual pigment molecule involved in entrainment that is not rhodopsin.

melanopsin, cryptochrome

48. How do you prepare a rat, surgically, to show that electrical stimulation of the brain is rewarding, and what is the behavioral paradigm?

survival stereotaxic surgery, double electrode in hypothalamus on plug in head mount in a Skinner box where electrical stimulation is the reinforcement for bar press

49. "The 'pyramidal smile' (voluntary facial paresis) results from an inability to voluntarily move the lower facial muscles on one side due to a unilateral lesion. Answer either how you could over-ride this distorted smile or what the symmetrical smile is called.

in the involuntary response, say, to humor, one gets the Duchenne smile

50. Who was the famous railroad researcher who got a spike driven through his brain?

phineas Gage

51. There are two enzymes that convert testosterone into important hormones. Five alpha reductase forms DHT. ANSWER EITHER (1) What is the other enzyme? OR (2) What is its hormone product?

aromatase, 17 beta estradiol

52. Testosterone under the skin of a female rat pup would do what to the feeding behavior when she is an adult?

feeding would be more like that of a male, animal would get heavier than a female

53. "Circulating testosterone is what makes 5 year old boys' behavior different from that of 5 year old girls." Support or contest that statement.

there is none, it is perinatal levels that had a permanent organizing effect

54. How is the somatosensory cortex different for non-lactating vs lactating female rats?

there is a larger representation for the ventrum (where the nipples are) if lactation

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

beta carotene, lutein, zeaxanthin

56. Why do human retinal pigment epithelial cells accumulate lipofuscin, the aging pigment?

for a lifetime (since RPE cells are not replenished by mitosis), they phagocytose the sloughed tips of rods, and lipofuscin is the indigestible residue of the phagolysosomal system

57. 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

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

sensitivity to ultraviolet light

59. "The human lens absorbs about 4 log units of light at 350 nm." How did Prof. Stark and Scott Griswold, his undergraduate premedical student, determine this noninvasively?

compare spectral sensitivities of subjects with vs without a lens


60. A pigeon learns well in a Skinner box and then is retired for many years in a home cage. Placed back in the Skinner box for the first time after many years, what is the performance like and why?

it is at the level years earlier suggesting that forgetting is not as important as extinction

61. Subject HM, studied by Brenda Milner, could learn a mirror drawing task. Does that mean he is cured?

no, procedural memory may be present, but declarative is gone

62. How does the radial 8-arm maze show that a rat has a special appreciation of the space in which it lives in its working memory?

quickly learns to visit all 8 arms

63. Beta and gamma secretases cut (what?) into (what?) relevant to memory.

amyloid precursor protein into beta amyloid

64. 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

65. 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

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