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Flashcards in Neural repair and plasticity Deck (10)
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1
Q

Can axonal repair occur in CNS? PNS? Can neuron replacement occur in the CNS? PNS?

A

Axonal repair can only occur in the PNS

If a neuron dies, it is not replaced

2
Q

What happens when transection of an axon occurs in the CNS? What mediates (protein) reactive gliosis?

A

Astrocytes undergo reactive gliosis which walls off the site of injury. This prevents axonal regeneration from happening

glial fibrillary acidic protein (GFAP)

3
Q

can you test for reactive gliosis present?

A

yes

You can stain for GFAP

4
Q

What happens when transection of an axon occurs in the PNS?

A

transection of an axon in the PNS results in Wallerian degeneration - axon distal to the site of injury degenerates. Schwann cells proliferate and remove the dibris of the distal axon. Schwann cells then grow a scaffold for the axon to grow through

5
Q

What 2 extrinsic factors promote axonal regeneration in the PNS?

A

nerve growth factor (NGF)

brain-derived neurotrophic factor (BDNF)

6
Q

what is the rate of axon regeneration?

A

1mm/day

7
Q

Why does reactive gliosis occur?

A

it walls off the site of damage, but more importantly fills in the empty space as the CNS needs a structure/scaffolding for support

8
Q

Describe plasticity at the neuron level (2 types)

A

short term: increased neuronal firing and increase in post-synaptic receptors to strengthen synapse

Long term: creation of collaterals that increase the strength of synapse

9
Q

Describe neuroplasticity of a microcircuit

A

If a damaged neuron can no longer perform its function (it dies), a microcircuit is rewired so that axons with similar functions take over the fucntion/response of the lost neuron

10
Q

describe neuroplasticity at the cortical level

A

the loss of a limb or stroke to a certain region of the brain results in remapping of functions