Myelin & Myelination

Question 1

What is the effect of loss of myelin

Answer 1

neurological disorders

Question 2

What synthesises myelin

Answer 2

non-neuronal cells

Question 3

What is the function of myelin

Answer 3

increase conduction velocity

Question 4

What is myelin

Answer 4

electrical insulator

Question 5

What is myelin made of

Answer 5

water, dry lipid, protein

Question 6

Describe the appearance of myelin

Answer 6

banding pattern - dark and faint bands

Question 7

What are the nodes of ranvier

Answer 7

gaps between myelin sheath

Question 8

Describe the intra period line

Answer 8

faint

Question 9

What makes up the intra period line

Answer 9

linked external proteins

Question 10

Describe the major period line

Answer 10

dense

Question 11

What makes up the major period line

Answer 11

linked internal proteins

Question 12

What synthesises myelin in the CNS

Answer 12

oligodendrocytes

Question 13

What synthesises myelin in the PNS

Answer 13

Schwann cells

Question 14

Describe the myelination by oligodendrocytes

Answer 14

myelinate several parts of an axon or several axons

Question 15

Describe the myelination by schwann cells

Answer 15

myelinate only one axon

Question 16

What happens in knockout mice for cerebrosides

Answer 16

myelin develops vacuoles - doesn’t function properly

Question 17

What symptoms are shown by cerebroside knockout mice

Answer 17

paralysis

Question 18

what are cerebrosides

Answer 18

complex lipids

Question 19

Where are cerebrosides located

Answer 19

sheaths of nerve fibres

Question 20

What is the difference between CNS and PNS myelin

Answer 20

PNS - less cerebroside and sulfatide, CNS - more sphingomyelin

Question 21

What are the CNS myelin proteins

Answer 21

myelin basic protein, proteo-lipid protein

Question 22

What is gimpy

Answer 22

natural mutation affecting proteolipid proteins

Question 23

What are the symptoms of gimpy

Answer 23

early death, loss of oligodendrocytes,

Question 24

What is produced in gimpy mice

Answer 24

toxic mutant PLP

Question 25

Where is myelin basic protein most abundant

Answer 25

white matter

Question 26

What can myelin basic protein induce

Answer 26

experimental allergic encephalomyelitis

Question 27

What are the PNS myelin proteins

Answer 27

P0, PMP22, MBP

Question 28

Which is the most abundant PNS myelin

Answer 28

P0

Question 29

What is P0

Answer 29

adhesion molecule - important for compaction

Question 30

Defect in which PNS myelin protein causes charcot marie tooth syndrome

Answer 30

CMT 1b in P0

Question 31

What is MS

Answer 31

primary demyelination autoimmune disease

Question 32

What are the symptoms of MS

Answer 32

variable severity, relapsing/remitting, progressive

Question 33

What degrades the myelin in MS

Answer 33

macrophages and protease activity

Question 34

What is the therapy for MS

Answer 34

steroids, interferons, immune suppressants, stem cells

Question 35

When does Guillan Barre syndrome develop

Answer 35

post viral/bacterial infection

Question 36

Describe Guillan Barre syndrome

Answer 36

Acute inflammatory response triggers demyelination

Question 37

How is Guillan Barre syndrome treated

Answer 37

intravenous immunoglobulin