Different Cell Types in the CNS One

Question 1

What are the glial cells in the brain?

Answer 1

Microglia
Oligodendrocytes
Satellite cells
Ependymall cells
Schwann cells (PNS)
Astrocytes

Question 2

What are other cells in the brain apart from glia and neurons?

Answer 2

Pericytes
Endothelial Cells
Fibroblast like cells
T cells (Very scarce)

Question 3

What are the most abundant cells in the brain?

Answer 3

Glial cells

Question 4

What is the role of microglial?

Answer 4

They are professional phagocytes - They have the largest variety of things they phagocytose

(Location = more specific function)

Question 5

What is the origin of microglia?

Answer 5

They are of myeloid/ monolytic origin (Like RBC…)

Question 6

Microglia are essentially:

Answer 6

Immune cells of the brain ( as are astrocytes and endothelial cells)

Question 7

Are all microglia the same?

Answer 7

There are different FUNCTIONAL subsets of microglia (express different markers and have different morphology)

Question 8

As professional phagocytes what do microglia respond to?

Answer 8

Cytokines during inflammation to increase their phagocytic activity i.e In alzhiemers

Question 9

During injury other that phagocytose what else may microglia do?

Answer 9

During injury microglia may secrete proinflammatory cytokines and present antigens to other immune cells (APC)

Question 10

Are microglia static?

Answer 10

Microglia are dynamic and can move locations therefore can change function

Question 11

How are microglia subsets classified?

Answer 11

Morphology (bad)
Very few immunological names
Functional makers (common and good)

Question 12

Why is microglia classification using appearance bad?

Answer 12

Appearance is subjective

Question 13

What sort of immunological markers could be used to classify microglia?

Answer 13

Chemokine receptors (CCR)
HLA markers
MHC’s (major histocompatibility complexes)
Cytokine production

Question 14

Why would immunological markers be a good way to classify microglia?

Answer 14

As they elude to cellular function

Question 15

What are three reasons why microglia would make good therapeutic targets?

Answer 15

1) Enhanced phagocytosis for debris clearance
2) Enhanced inflammation (cytokine / chemokine strategies)
3) Suppression of APC (MS/Stroke/Autoimmunity)

Question 16

What are two problems with targeting microglia for therapeutic reasons?

Answer 16

1) Microglia are functionally diverse (APC vs Phagocytosis) therefore target specificity (indistinguishable atm)
2) Crossing BBB

Question 17

What is the major function of astrocytes?

Answer 17

CNS health

Question 18

What are some functions of astrocytes?

Answer 18

Support neurons by:
Neurotransmitter supplies / clearance (glutamate excitotoxicity)
Waste removal
Nutrient supply

Maintenance support of neurovascular unit
May have progenitor qualities

Supply neutrotrophic factors

Question 19

Describe astrocyte structure

Answer 19

Astrocyte foot processes extend around blood vessels and neurons

Question 20

What do neutrotrophic factors do?

Answer 20

Growth factor and for survivial

Question 21

List three supporting roles astrocytes have

Answer 21

Neurovascular support
Neuron support
Immunological support

Question 22

What is the role of astrocytes during inflammation?

Answer 22

They have a immunological function

Resident brain innate immune cells

Question 23

During injury what do astrocytes do?

Answer 23

Migrate towards the site of injury

Produce and respond to cytokines/chemokines/ neutrotrophic factors

Question 24

What are some examples of chemokines that astrocytes produce?

Answer 24

IP10
IL8
MIP1
MCP1

Question 25

What are the functions of chemokines?

Answer 25

Attract other immune cells to the site of damage (chemoattractants)

Question 26

During inflammation what do neutrotrophic factors do?

Answer 26

Prevent neuronal death

Question 27

Whats an effective staining method for astrocytes?

Answer 27

They are GFAP postive so staining this will make astrocytes stand out distinctively