BB Lecture 4 Principles of Neuron Cell biology

Question 1

Neuropathy

Answer 1

damage to a single nerve or nerve group, which results in loss of movement, sensation, or other function of that nerve.

Question 2

Charcot-Marie-Tooth

Answer 2

demyelination disorder caused by dominant mutations in PMP22 (peripheral myelin protein 22)

Question 3

What does calcium do in the presynaptic terminal?

Answer 3

Ca2+ influx into presynaptic terminal allows neurotransmitters to be exocytosed; concentration of calcium at NMJ directly proportional to amoutn of neurotransmitter released

Question 4

Does the PNS or CNS have only excitatory signals?

Answer 4

PNS only has excitatory signals at synapse; CNS can have both excitatory and inhibitory

Question 5

Lamber-Eaton

Answer 5

refers to a type of myasthenic syndrome in which antibodies are produced that fuck up presynaptic Ca channels

Question 6

Botulinum

Answer 6

affects the binding of tSNARE and vSNARE such that vesicles can’t exocytose

Question 7

Synaptic integration

Answer 7

the concept of how the postsynaptic cell interprets the signals it receives at the synapse

Question 8

EPP

Answer 8

End plate potential

Question 9

EPSP

Answer 9

Excitatory Post-Synaptic Potential

Question 10

IPSP

Answer 10

Inhibitory Post-Synaptic Potential

Question 11

axon hillock

Answer 11

region with high concentration of Na channels that initiates Action potential

Question 12

Time Constant

Answer 12

Passive Membrane property of post-synaptic cell; greater the time constant, the more likely two EPSPs can sum into an AP

Question 13

Length constant

Answer 13

passive membrane post-synaptic neuron property; longer time constant = morel ikely for threshold to be reached by two EPSPs

Question 14

Wallerian degeneration in PNS

Answer 14

PNS process; the process by which the parts of axon distal to the lesion degenerates by macrophages

Question 15

What happens in a PNS damaged neuron?

Answer 15

You get more Nissl substance or more protein because it means the cell body is making more protein to regenerate lost axon

Question 16

Wallerian degeneratio in the CNS

Answer 16

In contrast to the CNS, distal axon fragments and myelin debris persists for much longer; thus affecting neighboring neurons

Question 17

Gliosis

Answer 17

when astrocytes are stimulated after injury in CNS to form a scar around a damaged region; may limit or prevent regrowth of processes

Question 18

Why don’t axons in CNS regenerate?

Answer 18

1. Inhibitory environment for growth (the glial scar)
2. Inhibitory molecules present in CNS myelin (Nogo, MAG, slit)
3. Low intrinsic growth potential of adult neurons