1. What information (and in what direction) is carried by axons of the cells in the dorsal root ganglion?__

somatosensory (also muscle stretch, etc.) afferent

2. Why would a neuroscience snob tell you that the cell bodies that make the optic nerve should not be called "ganglion cells?"__

because they are part of the central nervous system (hence nuclear) would be the more accurate term

3. Occlusion of one internal carotid might not be fatal because of (what structural adaptation?)._ _

circle of Willis

4. In explaining fluorescence, why is the emission a longer wavelength than the excitation?__

energy is lost before a photon is re-emitted

5. "Fluorescent- or gold-labeled secondary body." Answer either (1) What specific molecule does the secondary antibody bind to? or (2) Why gold? (referring to immunocytochemistry)__

primary antibody, electron dense

6. How was Ramon y Cajal able to produce pictures of neurons in intricate detail?__

Golgi's technique fully stained one cell. Since surrounding cells were not stained, he could draw the ones that were stained__

7. "Histochemical fluorescence was used in the 1960's to trace the dopamine tracts from the substantia nigra." Answer either (1) What was it that fluoresced? Or (2) How did they (researchers in the 1960's) determine these tract pathways?__

(1) dopamine (reacted chemically) (2) histological sections allowed following the tracks that fluoresced

8. Lashley, concluding that memories were stored all over the cerebral cortex, came up with the term "equipotentiality." By contrast, textbooks colorize the cortex to present what alternative viewpoint on how the cortex represents specific sensory and motor systems?_ _

localization of function

9. What is the explanation for CMT subject JH not knowing that he ruptured his Achilles tendon?

loss of sensation

10. When JH, our subject with CMT (the peripheral neuropathy) showed us how small his calves are, he made an analogy to what famous viral demyelinating disease?


11. Even when CMT disease patient JH had high arches and hammer toes from an early age, how is it conceivable that he was not diagnosed until age 62?

doctors only look at feet if the patient is a diabetic

12. In the neurons and glia lecture, we referred to two components of the blood brain barrier between the blood and the cerebrospinal fluid. Identify one of these.

capillary endothelium plus astrocyte end foot

13. "Major and minor dense lines alternate in the layers of myelin." Answer either (1) What makes up the major line? (2) What makes up the minor line? Or (3) What is meant by dense?

(1) the two intracellular membrane sides (2) the two extracellular membrane sides (3) electron dense, dark in a transmission electron microscope

14. Relate the concept of the motor unit with Halstead's theory of the cause of post-polio syndrome.

one spinal motor neuron innervates multiple muscle cells. Surviving ones sprout to innervate more during recovery. These sprouts are lost in post-polio syndrome

15. EAE (experimental allergic [autoimmune] encephalitis) is an animal model for what disorder?


16. Ouabain is applied to the cell. Answer either (1) Why does the resting potential change by only a few mV? or (2) Why doesn't the resting potential go away completely?

3 sodiums to 2 potassiums make the pump electrogenic, otherwise potentials are based on huge reservoirs of ion gradients that would run down very slowly if the pump were blocked

17. If I were on the ordinate (Y axis) and V were on the abscissa (X axis), what electrical term is used to describe the slope of the line?

conductance (g)

18. In contrast with "all-or-none" give the general term for those smaller potentials of variable size that can be either depolarizing or hyperpolarizing. (One is for sensory receptor potentials the other for synaptic potentials.)

generator-sensory, graded-synaptic

19. After being open, sodium channels have something, and the word "close" does not fully convey the meaning of (what is the correct word)?


20. In Hodgkin and Keynes' classic experiment on the sodium pump, how did they obtain numbers for the Y-axis (ordinate) that relate to sodium efflux?

measured radioactivity after loading axon with radioactive sodium

21. People who thought vaccines caused autism sometimes blamed what mercury-based preservative?


22. Explain why the electrical potential calculated with the Nernst equation is called the equilibrium potential.

the assumption (electrical and chemical potentials equal and opposite, or total energies of both systems are equal) is tantamount to equilibrium

23. When the AC (fast) Wheatstone bridge of Cole and Curtis swung out of balance, what did that tell us about the membrane events at that moment?

resistance changed (decreased) during action potential

24. Loss of what hormone, from an adrenalectomy, would make a rat crave salt?


25. Why would long QT syndrome limit a person's ability to respond to stress?

inability to have shorter action potential in the ventricular myocardium would limit how fast the pulse can get

26. "The time constant is independent of radius." Then why are giant axons faster?

the space constant relates to the square root of the radius

27. To hold the voltage of a squid giant axon at a clamped level of 0 mV, Hodgkin and Huxley had to pump current out through the membrane at 0.5 ms (fairly early) to compensate for what?

sodium current

28. A certain voltage is applied at one place in an axon. On the basis of passive spread only (no action potentials) what would be the voltage (relative to the applied voltage) one space constant away? (Your answer can be very approximate.)

1/3 approximates 1/e

29. What would be the cause of death if you ate a puffer fish?

sodium channel block, no action potentials

30. Why was it useful to obtain conditional mutants (like temperature- or ether-sensitive mutants), rather than ordinary mutants, to isolate genes like shaker and ether-a-go-go in Drosophila?

channelopathy mutants would be lethal

31. Why do they distinguish Shaker vs Electrophorus channels as tetramer vs pseudotetramer?

it takes 4 shaker proteins, the electrophorus protein has all 4 domains in one big molecule

32. How does the shaker protein detect voltage?

s4, with it's positive charges, rotates

33. Some potassium channels do show inactivation. What part of the molecule is responsible?

stopper on the N-erminus

34. Why do they refer to "omega figures" in the ultrastructure of synapses?

vesicles in the process of release are shaped like Greek letter omega

35. What happens to the conductance at the postsynaptic ionotropic receptors for K+ and Cl- for the IPSP?

they go up

36. With very low Ca2+, upon stimulating the motor neuron's axon, the end plate potential (EPP) was usually 0.4, 0.8, 1.2, etc mV. What other size was observed?


37. "Silencing of synaptotagmin in PC12 cells inhibits Ca2+-evoked catecholamine release." Why does calcium elicit release if synaptotagmin is not inhibited?

calcium, coming in through calcium channels, mediates vesicle release

38. "Botulism and tetanus toxins cleave synaptobrevin." Precisely what membrane is synaptobrevin on?


39. Suppose you voltage clamp a postsynaptic neuron to a level negative to the reversal potential. What would you record (postsynaptically) if you activated a cell making a GABAergic synapse?

in this case it would depolarize

40. Name a protein involved in recycling of synaptic vesicle membrane.

clathrin, dynamin

41. Reuptake is the standard mechanism for the termination of neurotransmitter action. In contrast, how is the action of acetylcholine terminated?

breakdown by acetylcholinesterase

42. "The nicotinic receptor is ionotropic." Translate: What is the transmitter? What is the molecular structure of the receptor? (Answer both.)

acetylcholine gates a channel

43. How is POMT (proopiomenanocortin) processed to yield beta-endorphin?


44. Say something about how vesicles or enzymes for transmitter synthesis get from the cell body to the synaptic terminal.

axon transport along microtubules

45. Give one of the two possible reasons a diet high in tryptophan might make you sleepy.

precursor to serotonin and to melatonin

46. Acetylcholine and nicotinic receptors are used in parasympathetic ganglia. What transmitter and transmitter receptor would you find at sympathetic ganglia?


47. Cyclic GMP's breakdown is inhibited by what drug (or class of drugs)?

viagra (also Levitra Cialis) ED meds

48. On the news was the case of a defendant blaming the murder he committed on Zoloft (the Zoloft defense). Why would he have Zoloft in his system?

for depression

49. Excitotoxicity, and too great an influx of calcium ions, is caused by overstimulation of synapses for what transmitter?


50. When more acetylcholine is needed, vesicles are released. How is the "transmitter" NO (nitric oxide) increased when it is needed?

turn on endothelial nitric oxide synthase (eNOS)

51. Contrast the presence or lack of l- vs d- isomers for DOPA, dopamine, and norepinephrine.

dopa could be l or d, also NE but dopamine's carbons do not have 4 separate groups

52. "Day length" (what fraction of a 24 hr period is illuminated) affects the size of the testes in a hamster by Answer either (1) What hormone? Or (2) From what brain structure?

melatonin, pineal

53. Explain either (1) why schizophrenia was once attributed to a serotonin defect, or (2) why this hypothesis was later excluded.

an LSD trip seemed like psychosis and LSD affected serotonergic transmission, but amphetamine induced psychosis was more similar to schizophrenia (and eventually overexcitation with dopamine was demonstrated)

54. Why does it take a lot of DOPA to treat Parkinson's disease?

very little is available to cross the blood brain barrier because the decarboxylase is everywhere

55. What class of molecules serves as the precursor for endocannabinoids?

membrane phospholipids

56. What would Prozac, Paxil or Zoloft do to the concentration of what transmitter in the synaptic cleft?

increase serotonin

57. "Naloxone, an antagonist, displaced certain narcotic analgesics in brain binding." This finding led to the isolation of what kind of receptor?

the opiate receptor

58. How did they show that the Raphe nuclei send serotonin all over the brain?

histochemical fluorescence tract tracing, formaldehyde turned serotonin into a fluorescent product

59. "Lesions of the lateral hypothalamus result in a thinner rat." In what way does this story relate to Parkinson's disease?

loss of affect (motivation) results from disrupting dopaminergic tract

60. Caffeine inhibits what enzyme?

the phosphodiesterase for cAMP

61. Inositol trisphosphate is a ligand for what kind of channel located where?

calcium on smooth endoplasmic reticulum (calcium cistern)

62. It takes 4 cAMP molecules to activate PKA. How (biochemically) do they do that?

2 each bind and remove 2 inhibitory subunits from 2 catalytic subunits

63. Why would atropine save your life if you were dying of acetylcholinesterase inhibitor poisoning?

block muscarinic receptors that are making the heart stop when there is too much acetylcholine

64. The NMDA receptor (answer either) (1) is for what transmitter? Or (2) passes sodium, potassium and (what other important ion?).

glutamate, calcium

65. What would you give a patient with myasthenia gravis to relieve the symptoms?


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last revised 2/15/18