030, 031 Glia, myelination, Degeneration, Regeneration

Question 1

What is the action of cannabinoids on synaptic function?

Answer 1

1. Canniboids bind to the CB1R receptor on neurons/astrocytes.
2. Astrocytes release glutamate on AMPA - post synaptic receptor of dendrites.
3. AMPA suppresses synaptic strength caused by NMDA receptors on post synaptic neurons.

This especially affects schaffer collaterals in cingulate cortex of the hippocampus.

Question 2

How do glial cells cause chronic pain?

Answer 2

1. Damage to sensory neurons activates microglia.
2. Astrocytes release ATP/adenosine
3. Adenosine binds to P2X receptors on activated microglia
4. Causes release of BDNF by microglia
5. BDNF causes pain neurons to be hypersensitive by changing chloride potential.

P2X adenosine receptor blocker to block pain.

Question 3

What initiates multiple sclerosis?

Answer 3

Initiated by T cell infiltration and secretion of cytokines that start the inflammatory response and enhance permeability of blood brain barrier.

Question 4

Why do you use B interferons to treat MS?

Answer 4

Anti-inflammatory molecule

• Extends the period in between relapses
• reduces the severity of attacks
• decreases formation of new neurons.

Question 5

How does natalizumab work?

Answer 5

Binds to cell adhesion molecule alpha4 integrin.

- prevents homing of inflammatory cells.

Question 6

How does alemtuzumab work?

Answer 6

Binds to CD52 on monocytes, lymphocytes and granulocytes, which reduces capacity of inflammatory immune cells.

Question 7

How does glatiramer acetate work? How many amino acids does it contain?

Answer 7

Glatiramer acetate contains 4 amino acids. It imitates myelin basic protein and recruits Treg cells, which migrate into CNS and inhibits local immune reaction.

Question 8

How does mitoxantrome work?

Answer 8

Mitoxantrome is cytotoxic and interferes with DNA synthesis and repair, suppressing variety of immune cells.

Question 9

What do schawnn cell myelin contain?

Answer 9

Protein zero
Myelin basic protein
Preripheral myelin protein 22

Question 10

How do schwann cells stimulate repair after injury?

Answer 10

It stimulates a repair schwann cell which supports repair and regrowth.

1. Breaks down myelin (inhibitors of axon growth - MAG, Omg)
2. Stimulates nerve growth factor and BDNF
3. Generates bands of bunger that guide axons backq

Question 11

Where in the brain do glial cells cause regeneration of neurons?

Answer 11

Subventricular zone of lateral ventricles and hippocampus –> stem cell sfrom astrocyte like adult neural stem cells.