1. With your "orange stick," you scrape all the gray matter out
of one sulcus. Answer either (1) How can you tell what direction the myelinated
axons run? or (2) Where do the first axons you find come from and go to?
stick glides in axon direction and scrapes across the grain, from and to
the adjacent gyri
2. In the corticospinal tract, these motor cells in the precentral gyrus
make their first synapse (where?).
to the spinal motor neuron in the ventral horn
3. You have a rat brain atlas and your anesthetized rat (in an approved
protocol) is mounted in a stereotactic device with the skull exposed. Say
something about what you need to do to get the tip of an electrode into
the ventromedial nucleus of the hypothalamus.
measure from the bone sutures*, drill a hole, lower the electrode to the
correct depth*, *=requires consulting the atlas
4. Before Pruissinger's prion hypothesis... answer either (1) What kind
of disease? was explained by Nobelist Gadjusec by a virus? (2) A virus with
what special kind of properties?
spongiform encephalitis, CJD, kuru, etc.; slow
5. The medial forebrain bundle goes through the lateral hypothalamus and
includes [answer either] (what famous tract?) that is disupted in (what
nigrostriatal tract, Parkinson's
6. What do you have to cut off to see the floor of the fourth ventricle?
7. The left side of the cerebellum controls which side of the body?
8. "Massa intermedia" is an operational term for what major relay
structure in the brain?
9. If you miss the midsagittal cut a tiny bit... Name one of the three tracts
you would see where the thalamus is located.
fornix, mamillothalamic tract, habenulopeduncular tract
For questions 10-13, see this
10. Name this structure (or give it's cranial nerve number)
olfactory bulb, I
11. This white matter is seen in the midsaggital view as... (name either
of the two tracts).
fornix, hippocampal comisure
12. What is this artery that feeds the circle of Willis?
13. What is this structure?
lateral geniculate nucleus (thalamus)
For questions 14-21, see this
14. These fibers, hidden as they pass under the pons, form what tract?
15. Here it is called the pons. What do you call these fibers, on the "other
side," in the dissection of the 3 components of the cerebellar peduncle?
brachium pontis or middle cerebellar peduncle
16. This one nucleus is in a system with two others. Name one of the two
putamen, globis pallidus
17. What is the frog's equivalent of this structure?
18. What is this major body of white matter called?
19. What was revealed after you removed this important limbic structure
wrapped in myelinated axons (i.e. under the structure you removed)?
20. The brains provided for your dissection still had this white "membrane"
(called what?) that you were required to remove before proceeding.
21. For this figure, answer either (1) What is it called when the entire
white matter under the cortical layers is exposed? or (2) What is the term
used for these particular axons?
corona radiata, arcuate fibers
22. After C-type sensory afferents arrive in the spinal cord, the projection
of this information ought to ascend in what portion of the spinal cord?
23. Why would you expect a Pacinian corpuscle to have a large receptive
since it is deep, deflection of a large area of skin would stimulate it
24. For either (1) Group I and II afferent axons or (2) Gamma motor neurons,
state what is feeding into it (for 1) or what it feeds to (for (2).
stretch receptors, intrafusal muscles
25. Capsaicin stimulates the VR-1 receptor. Answer either (1) What would
be the "normal" (biologically relevant) stimulus? (2) What related
Drosophila mutant was discovered much earlier? or (3) Say something about
the molecular structure of this receptor.
heat, transient receptor potential, channel
26. What is the difference between the gracile and cuneate tracts?
gracile is information from lower limbs, cuneate from upper
27. Why isn't the face included in the diagram of dermatomes?
trigeminal cranial nerve input is separate from segmented spinal cord input
28. In terms of axon type, what is the difference in the neospinothalamic
tract vs the paleospinothalamic tract?
neo A delta, paleo C
29. Most pain from the lower body travels in the anterolateral tracts. For
the exception, answer either (1) What kind of pain travels elsewhere? (2)
Where does it travel?
viceral pain, dorsal columns
30. The two point discrimination threshold is 3 mm for the index finger
and 45 mm for the calf. The tongue was not in the textbook figure, but you
should be able to give me that number here.
probably about 3 like the finger
31. The trigeminothalamic tract carries what particular type of information?
touch, pain, etc from the face
32. Your coverage in this course gave you only one neuron that releases
eckephalin. Where is it located?
dorsal horn, substantia gelatinosa
33. In what way is Planck's constant relevant to calculations concerning
used to calculate energy of one photon
34. Say something about why vision, as we know it, would not work for wavelengths
far below or above "visible wavelengths."
too short is ionizing (also cut off by ozone layer), just right excites
electrons, too long vibrates molecules (heat is waste)
35. "The cornea is the strongest lens in the eye." Explain this
in terms of relative indices of refraction.
the air to cornea interface is the only large difference in index of refraction,
so the corneal curve has a profound effect
36. For what visual disorder is angiogenesis an underlying cause?
37. "Foveal cones are protected from blue light" (by what?).
macular pigments (zeaxanthin and lutein)
38. A paper published in 1942 demonstrated that a rod can respond to a single
photon of light. Say something about the methodology in this study.
human subject answered if he could see carefully calibrated 500 nm light;
6-14 quanta were absorbed by a 500 rod area (psychophysics)
39. Histological autoradiography demonstrated that a radioactive amino acid
was incorporated into those disks of the outer segment nearest to the inner
segment. What eventually happened to this band of radioactivity?
over a few weeks, it moved up the outer segment until those disks were shed
and phagocytosed by the RPE
40. Say something about how there came to be genes for two of the cone rhodopsins
on the X chromosome in people.
in reevolution of mammalian colover fision after it was lost in an evolutionary
bottleneck, unequal crossing over in meiosis happened along the line, a
difference from old to new world monkeys
41. It might be better to say that "Light stops photoreceptor depolarization"
than to say "Light causes photoreceptors to hyperpolarize." Justify.
in the dark, cGMP keeps sodium-calcium channels open
42. Why is there lots of cGMP in a rod in the dark?
PDE is not activated
43. How was the horseshoe crab Limulus used to show how contrast detection
was enhanced by feature detection?
neural input from ommatidia at a light-dark boundry show a more accentuated
gradient of activity
44. Hubel and Wiesel referred to a cell in the striate cortex as "simple"
if it responded best to a line at an angle. Name one of the additional properties
of the cell's properties that earned it the designation of "complex"
line at an angle has to move in a preferred direction, or line must end
(have a corner)
45. On the way to the thalamus, what is different about axons from the nasal
vs the temporal retina at the optic chiasm?
temporal stays ipsilateral, nasal crosses to contralateral
46. For the ciliary ganglion, answer either (1) Where is the preganglionic
neuron's cell body? or (2) At the neuro-effector junction, what is the effector?
edinger-westfall nucleus, iris (or ciliary muscle)
47. What is different about layers 1,4 & 6 vs 2, 3, & 5 of the lateral
connected from contralateral vs ipsilateral retinas
48. A person is born with a cataract in one eye. What else will go wrong
if this situation is not remedied immediately?
the cortex will become blind to input from that eye
49. In a follow-up to Hubel and Wiesel's electrophysiology, what happened
to radioactive proteins made from an injection into one eye at the synapse
in the thalamus?
they crossed to postsynaptic cells
50. As an electrode is advanced across the primary visual cortex obliquely,
what changes in cell response properties are observed in addition to crossing
ocular dominance columns are observed?
preferred angle changes
51. Simple cells respond to a line at an angle. These cells presumably receive
inputs from an organized subset of lateral geniculate neurons whose receptive
field organization is (what?).
52. In the frequency discrimination demonstration, why was it important
to hold both tuning forks to one ear simultaneously?
to show, using beats, that they differed by just a few Hz
53. Why did Bekesy need to invoke lateral inhibition to make his data dovetail
with Helmholtz's place theory?
data showed that place localization on the basilar membrane was too crude
54. How does a kinocilium differ from a stereocilium?
kinocilium is a real cilium, not present in human adult hair cells, only
55. You have an electrode on a nerve in the auditory pathway and obtain
the data for a tuning curve. What are the axes of your graph?
X - frequency, Y dB
56. Mechanoreceptive channels in auditory hair cells are assisted by what
tip links, extracellular protein from one stereocilium to its neighbor
57. In addition to potassium channels, what other channels are important
in the transmission of input from the human auditory receptor cell?
calcium, also trp
58. Where is the first place in the auditory projection that receives bilateral
superior olive (mid-pons)
59. Say something about how a bat decides to cross paths with a moth but
does not make the mistake of crashing into a wall.
the moth would make a small echo that would vary in intensity
60. Name (or give the number for) an efferent cranial nerve that would mediate
eye movements controlled through the vestibular system.
occulomotor III, abducens VI (also trochlear IV)
61. How does a taste bud relate to a papilla?
there are many taste buds in a papilla
62. Bitter taste receptors are what kind of molecule?
g protein coupled receptor, T2R, TRA2R would be acceptable
63. The solitary nucleus gets input from nerves VII, IX and X, and it feeds
to the thalamus and (say another place).
64. In addition to the 5 primary taste receptors that input via nerves VII,
IX and X, say something about either the chemical ("tastant")
or the receptor type, or the nerve input mediating appreciation of food
at the level of watery stimulation in the mouth.
capsacin, polymodal niciceptive fibers, V = trigeminal
65. A male moth is excited by a female's sex attractant pheromone at a concentration
of one molecule per cubic foot. How does he know which way to fly?