Glia

Question 1

Astocytes (6 functions)

Answer 1

KNEGBS

• K+ buffering - maintains CNS extracell concentration
• NT regulation and metabolism (takes up excess EC NT like glutamate)
• Energy: Glycogen storage, lactic acid production and secretion for neuronal krebs
• GF production to promote synaptic formation/stabilization
• BBB
• Scars; form CNS scars (not fibroblast collagen)

Question 2

Oligodendrocytes

Answer 2

• form Myelin in CNS (one oligo can myelinate several axons)

Question 3

Schwann cells

Answer 3

PNS myelin; 1 schwann –> one internode of myelin

Question 4

NG2+

Answer 4

Glial progenitors (polydendrocytes) - not well established, some are oligo precursors

Question 5

Microglia

Answer 5

Bone marrow derived, enter CNS during embryogenesis and act as immune surveillance

• secrete cytokines/chemokines
• regulate immune rxn in response to infx or pathology
• can become macrophages in setting of tissue degeneration (phagocytose)
• found in any CNS lesion

Question 6

Ependymal cells

Answer 6

Ciliated epithelial cells lining ventricles, move CSF

Question 7

Choroid plexus cells

Answer 7

Covering fibrovascular stalk of choroid plexus, projects into ventricles for CSF production

Question 8

Neurons

Answer 8

Use lactate from astrocytes to make pyruvate –> energy

Question 9

GFAP

Answer 9

antigen produced by astrocytes (can be stained)

Question 10

Glutamate

Answer 10

excitatory NT, very prevalent in the brain and very important. Astrocytes suck it up so that there isn’t too much lying around in the space/messing with firing of neurons

Question 11

Neuronophagia

Answer 11

virally infected neuron will be engulfed by microglia (pathognomonic for viral encephalitis)

Question 12

Amyloid plaque

Answer 12

found in alzheimers, microglia are in and around the plaque

Question 13

Myelinophages

Answer 13

delineate the margins of a plaque, lots of microglia in MS plaques

Question 14

brain tumors

Answer 14

most are of glial origin