2. Cellular physiology of the brain

Question 1

compare amount of glial cells to neurons

Answer 1

10x more glial cells

Question 2

which AA is important for astrocytes to remove from synapses?

Answer 2

glutamate, to prevent toxicity

Question 3

why don’t neurones produce/store glycogen?

Answer 3

lack enzymes to produce it

Question 4

astrocytes produce lactate. Then what happens?

Answer 4

shuttled via MCT 1 & 2 to neuron, lactate converted to pyruvate

Question 5

what forms the blood brain barrier?

Answer 5

endothelial cells of capillaries

Question 6

name molecules that freely cross BBB

Answer 6

water
co2
o2
lipophilic gases

Question 7

why and how is the CNS immune privileged?

Answer 7

too much inflammatory response within a rigid skull would be harmful

microglia can act as APCs to T cells, and CNS inhibits imitation of pro inflammatory T cell response

Question 8

where is an AP generated?

Answer 8

axon hillock

Question 9

effect of inhibitory interneurones in spinal cord releasing glycine?

Answer 9

inhibits efferent nerve to antagonistic muscle

Question 10

where are nicotinic ACh receptors?

Answer 10

neuromuscular junction
ganglion synapse in CNS

Question 11

where are muscarinic ACh receptors?

Answer 11

postganglionic parasympathetic

Question 12

why can levodopa be used to treat Parkinson’s?

Answer 12

freely crosses BBB, then converted to dopamine by AADC in brain

Question 13

which drug can help levodopa exert more effect in the brain?

Answer 13

carbidopa, inhibits AADC in periphery so more LDOPA reaches brain

Question 14

drug to treat depression/anxiety

Answer 14

serotonin selective reuptake inhibitors (SSRIs) so more serotonin around

Question 15

anticholinergic poisoning symptoms (nightshade)

Answer 15

dryness
confusion
tachcardia
mydriasis