Neural Regeneration Flashcards Preview

Hugh's MD1 Neuro > Neural Regeneration > Flashcards

Flashcards in Neural Regeneration Deck (20):
1

What is the difference between axonal sprouting and regeneration?

Sprouting is when an existing axon produces a new synaptic process

Regeneration is the complete regrowth of a former axon

1

What do myelin inhibitors do?

Bind to regrowing axons and inhibit regrowth

2

How can you treat PNS nerve injury?

Microsurgery

3

What occurs 3 weeks post injury in PNS nerves?

Schwann cell proliferation - produce good environment for nerve growth

 

New nerve fibres grow downstream and attempt to reattach

 

 

3

What occurs minutes to hours after CNS injury?

Ischaemia

Ca++ influx

Lipid perioxidation and free radical production

BBB loss

Glutamate excitotoxicity

5

Do CNS or PNS nerve regenerate better?

PNS

6

What occurs in PNS nerves if regeneration isn't successful?

Neuroma formation - bundle of nerve fibres that can be quite painful

7

Is the immune response good or bad in CNS injury?

Bad

7

What forms at the resolution of CNS injury?

Glial scar

Astrocytic gliosis

Syrinx (cavity) formation 

 

7

How does astrocytic gliosis affect axon regeneration?

Generally impedes regeneration and in the worst case can lead to glial scar formation that blocks neuronal regeneration

8

Can you completely inhibit astrocytic gliosis as a means of allowing repair?

No, it still performs an important function: BBB regeneration, wound sealing, growth factors etc

10

How can you treat a CNS injury?

Remove the source to prevent further injury

11

What are the two site of stem cell reservoir in the CNS?

Hippocampus 

Lateral Ventricle

12

What are the two factors that prevent CNS neuronal regeneration?

Lack trophic support

Axon regrowth is inhibited by the injury environment

13

What is Wallerian degeneration? When does it occur?

Degeneration of axon and myelin sheath post injury

Phagocytosis of debris by macrophages

 

2 weeks

14

How do neuronal cell bodies appear 2 weeks after injury?

Loss of Nissl bodies aka chromolysis

Nucleus moves peripheral

16

Why do crush injuries repair faster than lacerations?

The structure of the Schwann cells and matrix is retained so they guide repair

18

What is the cause of secondary injury that occurs in the hours/days/weeks after CNS injury?

The inflammatory immune response

19

How long does it take for successful regeneration of axon after damage?

~3 months

20

What specific damage does the inflammatory immune response cause at the site of CNS injury?

Axonal injury

Demyelination

Apoptosis of neurons and glials cells