Glia

Question 1

What are 3 unique features about glia (as opposed to neurons)?

Answer 1

1. No axons
2. Can divide
3. Inexcitable

Question 2

What make up the majority of cells in the brain?

Answer 2

Glia

Question 3

What are the 2 main classifications of Glia?

Answer 3

Macroglia and Microglia

Question 4

What are the 4 main types of Macroglia?

Answer 4

1. Astrocytes
2. Oligodendrocytes
3. Schwann Cells
4. Oligodendrocyte Progenitor Cells

Question 5

Astrocytes are processes that cover _____ and surround _____

Answer 5

neurons; synapses

Question 6

The end feet of astrocytes terminate on _____ (pial surface) and extend all the way to the ends of _____

Answer 6

blood vessels; synapses

Question 7

Oligodendrocytes are the the ____ as Schwann Cells are to the _____

Answer 7

central nervous system; peripheral nervous system

Question 8

What forms CNS myelin?

Answer 8

Oligodendrocytes

Question 9

What forms PNS myelin?

Answer 9

Schwann Cells

Question 10

Microglia are derived from blood _____, which are macrophages of the brain.

Answer 10

monocytes

Question 11

What is the origin of microglia?

Answer 11

the mesoderm

Question 12

What is the main glial function of astrocytes?

Answer 12

Uptake of Neurotransmitters

Question 13

Describe the glutamate uptake of astrocytes. What is the purpose of this uptake?

Answer 13

1. Glutamate: high affinity Na+ - dependent uptake
2. GlutaMINE synthetase (glutaMATE+NH4 –> glutaMINE)
3. Recycled to neurons (glutaMATE-glutaMINE cycle)

Purpose: to prevent excitotoxicity

Question 14

Describe the GABA uptake of astrocytes

Answer 14

1. High affinity NA+ - dependent uptake
2. GABA transaminase
3. GABA –> Krebs Cycle –> GlutaMATE –> GlutaMINE

Question 15

Radial glia are stem cells for neuronal ______ cells

Answer 15

progenitor

Question 16

Guidance of neuronal migration is when neurons move along what?

Answer 16

radial glial cell processes

Question 17

Glial ______ factors influence neuronal development

Answer 17

neurotrophic

Question 18

GDNF stands for what?

Answer 18

Glial cell line-derived neurotrophic factor

Question 19

What does GDNF do?

Answer 19

provides trophic support for dopamine neurons

Question 20

Astrocytes release what to promote synapse formation?

Answer 20

thombospondins

Question 21

Microglia prune excess what (even in the adult brain)? When does this occur?

Answer 21

synapses; during sleep

Question 22

Astrocyte end-feet surround blood vessels. Developing vessels grow along what?

Answer 22

glial processes

Question 23

Astrocytes release what growth factor?

Answer 23

VEGF: Vascular endothelial growth factor

Question 24

What type of junction is formed in the blood brain barrier?

Answer 24

tight junctions

Question 25

Astrocytes play a role in regulating ________ and help to regulate it in the brain by producing what kind of factors?

Answer 25

blood flow; vasoconstricting/vasodilating

Question 26

Microglia are resident ____ of the brain and are considered the interface between which body system and the brain?

Answer 26

macrophages; immune

Question 27

What are the intrinsic antigen presenting cells of the brain?

Answer 27

microglia

Question 28

What cells are constantly surveying the brain for injury?

Answer 28

microglia

Question 29

What cells differentiate into amoeboid-like cells to scavenge debris at the site of injury?

Answer 29

microglia

Question 30

What cells prune unneeded synapses during development?

Answer 30

microglia

Question 31

What is Reactive Gliosis?

Answer 31

the response of glial cells to brain injury or pathology

Question 32

Astrocytes have 3 main actions. What are they?

Answer 32

1. Proliferation/differentiation 2. Express GFAP (glial fibrillary acidic protein) 3. Form glial scars

Question 33

Which cells form glial scars?

Answer 33

Astrocytes

Question 34

Which cells express GFAP?

Answer 34

Astrocytes

Question 35

Which cells are known for proliferations/differentiations?

Answer 35

Astrocytes

Question 36

Microglia are known to differentiate into _____-like cells to scavenge for ____ at the site of injury

Answer 36

amoeboid; injury

Question 37

What cells mediate the immune response of the brain?

Answer 37

Microglia

Question 38

What cells promote regeneration of nerves in the PNS?

Answer 38

Schwann Cells

Question 39

What cells act as conduits for regenerating axons?

Answer 39

Schwann Cells

Question 40

T/F: Severed peripheral nerves CAN regenerate.

Answer 40

true

Question 41

What cells prevent regeneration of nerves in the CNS?

Answer 41

Oligodendrocytes

Question 42

What kind of proteins, such as Nogo, inhibit axon growth?

Answer 42

oligodendrocyte

Question 43

T/F: Regeneration CAN be partially restored in the CNS. Why or why not?

Answer 43

true, because there are 3 ways to do so: 1. Transplants of olfactory ensheathing cells (glia) 2. GDNF (glial cell line-derived neurotrophic factor) 3. Antibodies against oligodendrocyte proteins

Question 44

Why are SCI so devastating?

Answer 44

Because the CNS has a hard time regenerating nerves since oligodendrocytes PREVENT this

Question 45

Chronic pain can result from damage to what system?

Answer 45

PNS

Question 46

What cells play a role in chronic pain?

Answer 46

microglia

Question 47

What becomes activated in the dorsal (sensory) horn of the spinal cord following peripheral nerve damage?

Answer 47

microglia

Question 48

What do microglia release?

Answer 48

Diffusible factors, such as BDNF which is brain-derived neurotrophic factor

Question 49

What does the release of diffusible factors via microglia do? What is the clinical application of this?

Answer 49

1. Increases neuronal excitability --> 2. Increases pain --> 3. Chronic pain Result: Nerve blocks/corticosteroid injections to reduce pain needed

Question 50

In Alzheimer's disease, many mutations are expressed in the _____ rather than the neurons

Answer 50

microglia

Question 51

Microglia surround ____ and phagocytize _____

Answer 51

amyloid plaques; b-amyloid

Question 52

If microglia are mutated (damaged/altered), they cannot remove _____, which is linked to developing Alzheimer's

Answer 52

wastes/plaques

Question 53

In MS, autoimmune system attacks what kinds of cells?

Answer 53

oligodendrocytes

Question 54

In MS, the body believes myelin basic protein (and others) are _____ and attack the oligodendrocytes, which causes ________.

Answer 54

antigens; demyelination

Question 55

In Autism-spectrum disorders, the ____ are considered dysfunctional due to altered _____ and numbers.

Answer 55

microglia; morphology

Question 56

Microglial-specific mutations are commonly associated with what disorder?

Answer 56

Autism

Question 57

In Epilepsy, epileptogenesis can occur in regions of reactive _____ and ____ scars.

Answer 57

astrocytes; glial

Question 58

Abnormal glial cells may contribute to epileptogenesis due to the reduced uptake of which neurotransmitter?

Answer 58

glutaMATE

Question 59

Brain tumors are in less than 2% of all malignancies, but are largely untreatable. They are most commonly derived from ______, ______ and ______ cells which are glia lining the ventricles.

Answer 59

astrocytes; oligodendrocytes; ependymal

Question 60

Gliomas release what neurotransmitter which kills neurons and makes room for a tumor to grow in the brain?

Answer 60

glutaMATE

Question 61

The key factor in brain disease is what?

Answer 61

glutaMATE

Question 62

What are the main types of glial cells?

Answer 62

1. Astrocytes 2. Oligodendrocytes (CNS) 3. Schwann Cells (PNS) 4. Microglia

Question 63

Reactive gliosis mainly affects ____ and _____

Answer 63

astrocytes; microglia

Question 64

Glia can aid in regeneration in the ____ and hinder regeneration in the ____

Answer 64

PNS; CNS

Question 65

Glial cells are implicated in many ______ diseases

Answer 65

neurodegenerative