Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

developmental final > glial cells > Flashcards

glial cells Flashcards

1
Q

what cell types are found in the brain

A

macro and microglia and neurons

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

what cells are macroglia

A

astrocytes and oligodendrocytes and schwann

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

what does myelin compose? which matter

A

white matter in the brain

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

what is myelin

A

specialized membrane that surrounds axons and facilitates conduction through the axon in a rapid fashion

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

how does myelin speed transmission

A

it acts as an insulator along the axon allowing transmembrane currents at specific locations called nodes of ranvier

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

saltatory conduction

A

channels that allow ion flow and depolarization are only found in nodes of ranvier, in between myelinated sections of the axons and thus allows signal to skip down the length as action potentials are initiated and propagated.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

how can we visualize myelin

A

MBP staining, luxol blue staining and Electron micrograph

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

benefits of myelin

A

reduces energy consumption needed to restore the proper ionic gradients. important for long term axonal health and maintenance

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

when does myelination occur

A

one of the last processes to occur in development. humans third trimester until the 2 year.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

what fibers are the first to be myelinated?

A

motor fibers.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

which are the last to be myelinated

A

association cortex.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

which cells myelinate the PNS

A

schwann cells; any axon that is not in the brain or spinal cord.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

which cells or the CNS

A

oligodendrocytes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

where do schwann cells come from

A

neural crest cells

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

what other cells types are produced by neural crest

A

cartilage, bone, fibroblasts, doral root ganglia, melanocytes, smooth muscle and neurons

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

which gene can be used to detect schwann cell precursors

A

cad19

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

can schwann cells be cultured and detected?

A

yes. immature schwann cells can be identified by krox 20 they can be isolated from peripheral nerves

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

how many axons does one schwann cell associate with?

A

ONE; this one cells forms myelin around one segment of the nerve

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

which two proteins can be used to detect myelin?

A

MBP and MAG

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

what do schwann cells do after injury

A

the dedifferentiate, proliferate and produces agents that stimulate nerve repair

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

how do they differentiate and myelinate?

A

unknown mechanism, but it requires axon contact and probably involves signals from the axon.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

Neuregulin 1

A

proteins that regulate cell fate. I and II are most abundant and they are expressed in neurons. both oligo and schwann produce receptors (NRG, ErbB 1/2/3
regulates thickness of myelination

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

what are oligodendrocytes

A

they are the macroglia that myelinate the CNS.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

how many axons can one oligo myelinate

A

40-50

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

origin of oligodendrocytes

A

derived from early neural progenitors in the ventricular zone

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

how many waves of OL migration are there?

A

3

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

OPC wave 1

A

preoptic area

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

OPC wave 2

A

medial and lateral ganglionic eminences

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

OPC wave 3

A

cortex ventricular zone

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
30
Q

where do oligos come from?

A

neural progenitor cells. but we dont know which one. NG2 positive cells or glial restricted progenitors

31
Q

what problems from glial cell fate mapping studies

A

overlapping markers, cell culture conditions, KO’s are embryonic lethal, contradictory information

32
Q

how do we identify oligo precursors

A

A2B5 and PDGFR. they are simple and bipolar

33
Q

what can speed up OL differentiation

A

laminin (ECM) and Fyn kinase

34
Q

what is Fyn kinase necessary for?

A

process extension

35
Q

what is Fyn kinase

A

src family kinase (tyrosine), only member upregulated in OL development. gets recruited to cell membrane in response to signals. reguates process extension.

36
Q

schwann cell summary

A

1) myelinate 1 axon segment because whole cell is in contact with axon
2) PNS myelin. conposition is different from CNS.
3) hard to observe differentiation in culture, unless co-culture
4) can promote neuronal repair after injury

37
Q

oligodendrocytes summary

A

1) myelinate many axonss\
2) CNS is different than PNS
3) can easily assay in culture.
4) inhibits neural regeneration after injury.

38
Q

what is myelination for

A

rapid nerve conduction

39
Q

what is the most abundant glial cell

A

astrocytes

40
Q

how much of total brain are astrocytes by volume

A

50%. 40-50% glial cell population

41
Q

old theory of astrocytes

A

homogeneous population of non-excitatble cells that fill space between neurons

42
Q

new reality of astrocytes

A

dynamic heterogeneous population of cell

43
Q

astrocyte-to-neuron rule and ratio

A

there is an increase in the number of astrocytes per neuron with increasing brain complexity and size (4-7:1)

44
Q

where are protoplasmic astrocytes found

A

gray matter

45
Q

what do protoplasmic astrocytes do?

A

enfold neuronal cell bodies and prcesses they form multiple contacts with neurons (as many as 1 million) form end-feet with blood vessels

46
Q

what do protoplasmic astrocytes look like?

A

stellate or star shaped with many fine complex processes.

47
Q

what do fibrous astrocytes look like

A

stellate or star like with extensive processes scattered in the white matter of spinal cord and the brain

48
Q

where are fibrous astros found

A

in the white matter

49
Q

characteristics of fibrous

A

not as complex as protoplasmic, but have longer processes. run between myelinated fibers and contact axons at the nodes of ranvier. frequently form end-feet with capillaries

50
Q

radial glia are what

A

specialized glial cells with long unbranched processes.

51
Q

muller cells of retina

A

elongated throughout the thickness of the retina radial glial cell

52
Q

bergmann glia

A

goli epithelial cells of the cerebellum that extend through the molecular layer to the cerebral cortex.

53
Q

tanycytes

A

radial glial cells that located in the ependymal lining of the ventricles.

54
Q

what do radial cells do

A

they are scaffolding for neuronal cell migration they are produced in early in development and provide substrate for migrating neurons.

55
Q

what are astrocyte functions in neurogenesis and early development

A

1) scaffold for migrating neurons
2) help create brain microarchitecture
3) synaptogenesis
4) formation of the BBB

56
Q

astrocyte functions in neuronal homeostasis

A

1) regulates extracellular K+
2) neurotransmitter uptake and inactivation
3) control local blood flow
4) provide metabolic support to neurons
5) pH regulation
6) energy regulation

57
Q

astrocytes role in neuronal activity and plasticity

A

1) can regulate and limit number of synapses.

2) can aid in the maturation and stabilization of synapses

58
Q

what proteins do astrocytes provide for ECM

A

tenascin C/R and brevican

glial Ephrin A and Neuron EphA4 interactions regulate dendritic spine morphology

59
Q

BBB composition

A

composed of tight-junctino brain capillary endothelial cells that precludes entrance of substances into the brain.
seperates plasma from brain interstitial fluid.

60
Q

what forms the proper barrior for the BBB

A

endothelial cells. the interaction with astrocytes is required for the development.

61
Q

what ways do brain endothelial cells differ from regular

A

1) continuous tight junctions are present between the cells that prevents paracellular movement of molecules.
2) no detectable transednothelial pathways suhc as intracellular vesicles.

62
Q

what factors induce the BBB in endothelial cells

A

TGF-B, Glial-derived growth factor, bFGF, angiopoetin1, interleukin-6

63
Q

what factor is important for neurogenesis

A

neurogenin

64
Q

what pathway is important for the neuro-glia switch

A

STAT3

65
Q

what are microglia

A

resident macrophages of the brain.

66
Q

what percent of the brain do microglia compose

A

15%. they are widely distributed throughout the brain.

67
Q

what do microglia do

A

they are responsible for removing debris, and recrutied for injury. also pruning

68
Q

where do microglia come from

A

they come from the yolk sac.

69
Q

what is the fastest moving cell in the brain

A

microglia

70
Q

what do microglia do during development

A

eliminate unused connections and control the stem cell populations/

71
Q

what happens to microglia when they are activated

A

they assume an ameboid shape and migrate to areas of disease. they begin to produce immune molecules.

72
Q

what factors and characteristics of good microglia

A

decreased inflammation and increased phagocytosis.

IL-6, IL-1B, TNF-a, TGF-B, CX3CR1, CD45, NO

73
Q

what factors and characteristics of bad microglia

A

increased inflammation and decreased phagocytosis. CD40L, CX3CR1, CDK5/p25, s100B.

developmental final (9 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions