3. Neuronal cell biology

Question 1

What are the 4 points of the neuronal doctrine?

Answer 1

1. The neuron is the structural and functional unit of the nervous system
2. Neurons are individual cells not continuous to other neurons
3. The neuronal has 3 parts; dendrites, soma and axon
4. Conduction is from dendrites to some to end of axon

Question 2

Function of dendrites

Answer 2

Increase SA and receive outputs

Question 3

Function of axon

Answer 3

Carry information over long distances

Question 4

Function of hillock

Answer 4

Action potential origin

Question 5

Function of myelin

Answer 5

Coats axons, improves conductance

Question 6

Node of Ranvier function

Answer 6

Break in myelin sheath

Allows saltatory conduction

Question 7

Terminals function

Answer 7

output region
transmitter release
synapse with other neurones

Question 8

In which direction is retrograde transport?

Answer 8

Terminals to axon to soma

Question 9

In which direction is anterograde transport?

Answer 9

soma down axon to terminals

Question 10

Speed of retrograde transport

Answer 10

5 mm per day

Question 11

Speed of anterograde transport

Answer 11

rapid 300-400 mm per day

slow 5-10 mm per day

Question 12

Oligodendrocyte function

Answer 12

form myelin sheath

Question 13

Microglial cell function

Answer 13

scavengers

Question 14

Astrocyte function

Answer 14

mop up neurotransmitters

Question 15

What neurotransmitters can glia release?

Answer 15

ATP, glutamate

Question 16

Which NS are oligodendrocytes responsible for myelin?

Answer 16

CNS - wrap over parts of 50 neurons

Question 17

What causes myelin in the PNS?

Answer 17

Schwann cells wrap part of a single neuron

Question 18

Major proteins in CNS myelin

Answer 18

PLP

Question 19

Major proteins in PNS myelin

Answer 19

P0 and PMP22

Question 20

What do mutations in PLP cause in mice, rats and humans

Answer 20

mice - jimpy, shaking pup, rump shaker
rats - md
humans - Pelizaeus-Merzbacher Disease

Question 21

What do Th cells do in EAE?

Answer 21

Cause demyelination, chronic relapsing paralysis.

Question 22

Why does EAE result?

Answer 22

Mutation in T cell receptor gene V beta 8.2

Question 23

What can demyelination cause?

Answer 23

MS
CMT
Adrenoleukodystrophy

Question 24

What does a defect in P0 and PMP22 cause?

Answer 24

CMT

Question 25

How do the long chain fatty acids build up in ALD?

Answer 25

A deficiency in the peroxisomal enzyme catalyzing formation of lignoceroyl-CoA ligase
Defect in a peroxisomal membrane protein needed to import the ligase into the peroxisome