Neuronal Regeneration

Question 1

CNS can repair well T/F

Answer 1

F

Question 2

Why cant the CNS repair well?

Answer 2

Oligodendrocytes inhibit neuronal growth
Astrocyte Gliosis
Glial Scar
Phagocytes breakdown myelin more slowly

Question 3

The distal part of a regenerating axon extends proximally to repair T/F

Answer 3

F, the proximal part extends distally

Question 4

What is gliosis?

Answer 4

Expansion of the glia due to neuronal damage

Question 5

Define Sprouting

Answer 5

Expansion of the neuronal process of nearby axons after injury. Provides a limited improvement in functionality

Question 6

When is better repair achieved when the axon is cut or crushed? why?

Answer 6

Crushed. Myelin and Schawn cells can act as guide for axon regrowth

Question 7

Mechanism to help heal the axons in the PNS

Answer 7

Microsurgery

Question 8

What is chromatolysis and when does it occur?

Answer 8

In the first 1-2 weeks after injury. Loss of the Nissl substance after neuron damage

Question 9

What is the Nissl substance?

Answer 9

RER and Ribosomes close to the nucleus of the neuron

Question 10

Neuron histological look after 1-2 weeks of injury?

Answer 10

Nucleus is peripheral
Chromatolysis
Wallerian Degeneration

Question 11

What is Wallerian Degeneration?

Answer 11

Retrogade degeneration from the distal part of the axon to the proximal part

Question 12

what can be seen 3 weeks after neuronal injury?

Answer 12

increased Nissl substance
nucleus is central
increased schawn cell proliferation
axon growth towards distal end

Question 13

what can be seen 3 months after SUCCESSFUL neuronal injury?

Answer 13

electric conductivity restored

Question 14

if neuronal regeneration is unsuccessful what can be seen?

Answer 14

Neuroma formation. Distal bloob of axon. Sometimes painful

Question 15

What are neurotrophins?

Answer 15

molecules that stimulate neuronal growth and repair

Question 16

Glial Scar Formation is…

Answer 16

A barrier between the damaged and healthy tissue

Question 17

Glial Scar Formation is formed by…

Answer 17

deposition of extracellular matrix that inhibits neuronal growth by the astrocytes

Question 18

one of the main inhibitors of Neuronal Growth is?

Answer 18

Condroitin Sulphate Proteoglycans (CSPs)

Question 19

What are some of the substances found in myelin that inhibit neuronal growth?

Answer 19

Nogo, proteins

They all bind to NOgoR

Question 20

What is the main function of the proteins that inhibit neuronal growth?

Answer 20

decrease neuronal sprouting and keep axons healthy

Question 21

When are axon guidance molecules present?

Answer 21

During development

Question 22

During CNS repair what do astrocyte present in gliosis that inhibit neuronal growth?

Answer 22

guidance molecules get upregulated on the astrocytes

Question 23

What is the main function of the Rho Kinase pathway in neuronal repair?

Answer 23

Blocks the formation of growth cones

Question 24

What are the two main areas of neuronal regeneration in the brain?

Answer 24

Subventricular Zones of the Lateral Ventricle (SVZ)
Subgranular Zone (SGZ) of the Dentate Gyrus of the Hyppocampus

Question 25

What is a Neurosphere?

Answer 25

Pluripotent stem cells that can be introduced into the injured area in the hope of them transforming into new functional neurons

Question 26

What does EPO does to neurogenesis?

Answer 26

Increases and stimulates it