L2

Question 1

Name the three types of neuroglia

Answer 1

Oligodendrocytes, astrocytes and microglia

Question 2

What is the function of oligodendrocytes?

Answer 2

Produce myelin in the CNS for rapid action potential travel

Question 3

What is multiple sclerosis and what glia does it affect?

Answer 3

Chronic inflammatory and demyelinating disease. Autoreactive CD4+ activates in the periphery and enters the CNS by the BBB along with activated myeloid cells and B lymphocytes. Together, with brain resident immune cells cause an inflammatory environment that demyelinates neurons.

Question 4

What is the most abundant cell in the CNS?

Answer 4

Glial cells

Question 5

What is the least abundant cell type in the CNS?

Answer 5

Stem cells

Question 6

What is the origin of microglia?

Answer 6

monocytic/myeloid

Question 7

What is the main role of microglia?

Answer 7

Brain’s professional phagocytes that remove dead cell debris

Question 8

What do microglia do during brain injury?

Answer 8

Secrete pro-inflammatory cytokines and may present antigens (APCs) to other immune cells (T cells)

Question 9

Name 6 types of microglia focusing on two specifically

Answer 9

Foamy
phagocytic
antigen-presenting (inflammatory) activated
ramified
Specifically, perivascular which surround BVs and sense signals from the blood. Also parenchymal, which surround neurons and astrocytes and tend to be more phagocytic + in contact with neurons.

Question 10

Why are Microglia thought to be heterogenous?

Answer 10

Some are phagocytic and not. Some sense cytokines.

Question 11

Name some immunological markers.

Answer 11

HLA-DR, CD163, CD68, CD206, CD209, chemokine receptors,

Question 12

What do immunological markers show about microglia?

Answer 12

Allude to cellular function, context dependant (disease).

Question 13

Name 3 main strategies for microglia therapeutic targets.

Answer 13

1. Phagocytosis for debris clearance
2. Inflammatory response control (increase or dampen) eg. though use of NSAIDs
3. Suppression of APC activity (Stroke/MS/autoimmunity).

Question 14

Name 2 problems with the strategies for microglia therapeutic targets.

Answer 14

1. They need to target the correct subset of microglia

2. They need to pass the BBB which is selective

Question 15

What are the 2 support roles of astrocytes?

Answer 15

1. Support neural synapses

2. Support neurovascular units (vasculature)

Question 16

Are astrocytes produced in the bone marrow?

Answer 16

No

Question 17

Are astrocytes considered not immune cells proper?

Answer 17

Yes

Question 18

What is the result of diseases targeting astrocytes?

Answer 18

Loss of synaptic communication and a loss in BBB integrity.

Question 19

What are the 3 things astrocytes do during neuroinflammation to protect neurons from cell death?

Answer 19

1. Migrate towards the injury
2. Produce and respond to the chemokines recruited in the inflammatory response
3. Provide neurotrophic factors for growth and survival of neurons

Question 20

How are astrocytes detected?

Answer 20

GFAP+ is expressed by astrocytes and is detectable.