Neuronal Development, Survival & Differentiation Flashcards

1
Q

What is the ratio of neurons to glia cells?

A

10 % = neurons
90% = gliaCEl

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

Origin of nerve cells

A
  1. Neurons & glia = neuroepithelium, ectoderm
  2. Microglia = yolk sac
    microglia are derived from embryonic mesoderm, which gives rise to cells of the blood and immune system.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Neural tube becomes…

A

Neural progenitors (single layer, pseudostratified columnar)

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

What is the process of cell division in progenitor expansion phase (phase 1)?

A

Symmetrical cell division, interkinetic nuclear migration

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

The 1st generation of neural tube zones

A
  1. Preplate PP - 1st gen neurons = pial surface
  2. Intermediate zone IZ - axons
  3. Ventricular zone VZ - proliferative zone, radial glial cell body
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

How does migration on radial glia work?

A

The migrating neuron has CDK, neuregulin, NMDA-R1, integrin
The radial glia has integrin, laminin, fibronectin, NGCAM

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

Non-radial migration

A

Occurs horizontally, at the same time as radial migration
1. DISTRIBUTION OF INHIBITORY GABAergic neurons
2. Formation of brainstem nucleu

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

What layers does the preplate form?

A
  1. Marginal zone
  2. Cortical plate
  3. Subplate (will eventually disappear)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

The marginal zone becomes which cortical layer?

A

Cortical layer I, the first layer

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

The cortical plate develops …

A

Inside out, from cortical layer VI (closer to the ventricle) to cortical layer II (closer to the marginal zone or cortical layer 1)

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

Which zone becomes white matter?

A

Intermediate zone

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

The ventricular zone becomes

A

The subventricular zone.
The embryonic layer: ventricular zone goes away.

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

Sematophorin 3A

A

Axon goes down (away from higher concentration of semaphorin = long-range chemorepellent)
Dendrite goes up (pial surface)

This is a long-range cue for growth of axon.

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

Growth cone

A

Filopodia = feet = actin bundles
Lamillopodia = notch between feet = actin-myosin meshwork
Growth according to chemical signals.

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

Cadherins

A

Diffuse in ECM, contact attraction for the growth cone = the roadway

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

Ephrin

A

Contact repulsion, roadway guard rails

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

Netrins

A

Chemoattraction for growth cone, long-range cues

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

Mature neurons can be seen in LM due to

A

Nissl substance

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

Lipofuscin is found in

A

DRG
Sympathetic ganglion
Pyramidal neurons

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

Neuromelanin

A

Substantia nigra (dopamine)

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

Kinesin

A

Anterograde transport

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

Slow axonal transport for…

A

Cytoskeletal properties: neurofilaments, microtubules, axonal matrix

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

Fast axonal transport

A

Membrane bound organelles, vesicles, neurotransmitters, neuropeptides

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

Retrograde transport

A

Motor: Dynein,
Neurotrophic factors (NGF), rabies virus

25
Q

neuron reaction to injury

A

Chromatolysis
Wallerian degeneration

26
Q

Neuron cell body reaction to injury

A

“Chromatolysis” = Chromatolysis is a reactive change that occurs in the cell body of damaged neurons, involving the dispersal and redistribution of Nissl substance (rough endoplasmic reticulum and polyribosomes) in order to meet an increased demand for protein synthesis such as is required to regenerate axons.

Nuclear eccentricity
Cell swelling
Dispersed Nissl substance

27
Q

Wallerian degeneration

A

Wallerian (orthograde) degeneration is axonal degeneration occurring distal to the site of injury.
Wallerian degeneration is an active process of retrograde degeneration of the distal end of an axon that is a result of a nerve lesion. It occurs between 7 to 21 days after the lesion occurs. After the 21st day, acute nerve degeneration will show on the electromyograph

28
Q

Process of nerve regeneration

A
  1. Degeneration
  2. Phagocytosis by macrophages and Schwann cells
  3. Schwann proliferation
  4. regeneration of axon along endoneurial tube
29
Q

Neutrophin family receptors…

A

Tyrosine kinase

30
Q

NGF Nerve growth factor

A

Stimulates cholinergic forebrain neurons. May help in Alzheimer’s patients.
The NGF gene provides instructions for making a protein called nerve growth factor beta (NGFβ). This protein is important in the development and survival of nerve cells (neurons), especially those that transmit pain, temperature, and touch sensations (sensory neurons).

31
Q

BDNF, NT-3, NT-4

A

Neutrophins

32
Q

NGF pathway

A
  1. Ras-MAP
  2. Phospholipase C
  3. Phosphatidylinositol-3-kinase (PI3K)

This happens by retrograde transport from axon, stimualting growth survival and neuronal differentiation.

33
Q

Where are adult neural stem cells found?

A
  1. Subgranular zone of the dentate gyrus
  2. SVZ of lateral ventricles
34
Q

Symmetrical vs asymmetrical cell division

A

Symmetrical is for growing the NP pool.
Asymmetrical is for dividing into radial glia and neurons.

35
Q

What came first: neurons or glia?

A

Neurogenesis occurs first, then gliogenesis.

36
Q

How do glia cells develop?

A

Multipotent stem cells become glial progenitors, which start differentiating into astrocytes via Notch activation.
The astrocytes release PDFG, NT-3 which causes oligodendrocyte progenitor cell proliferation. After a while, cell cycle inhibitor p27Kip1 accumulates and tells them to stop dividing and start maturing.

37
Q

How do neural crest cells differentiate?

A

Proneural genes are activated by AMP from aorta, becoming SA progenitor.

SA progenitor becomes sympathetic neurons if activated by bFGF, but will become chromaffin cells if the are activated by glucocorticoids in adrenal gland.

38
Q

BMP2

A

Crest cells become neurons

39
Q

Neuregulin/GGF2

A

Crest cells become glia

40
Q

Macroglia make up … of glia cells

A

80%

41
Q

What is the most abundant cell in the CNS?

A

Astrocytes

42
Q

Neuroglia express …, intermediate filaments.

A

GFAP = glia fibrillary acidic protein
Can be used in immunostain to find astrocytomas.

43
Q

Which glia produces neurotrophic factors?

A

Astrocytes

44
Q

Which glia induces BBB?

A

Astrocytes

45
Q

Schwann cell origin

A

Neural crest, same as skin melanocytes

46
Q

Interferon beta

A

Slow MS progression
Improves integrity of BBB

47
Q

Overactivity of which glia cell may produce ALS, Parkinson, etc?

A

Microglia

48
Q

Ependymal cells

A

Ciliated cuboidal epithelial cells
They line the ventricles and central canal.
Gap junctions.

49
Q

Lens and cornea developed from ….

A

Ectoderm

50
Q

Anterior pituitary developed from …

A

Ectoderm

51
Q

Retina developed from …

A

Neural tube

52
Q

The notochord develops from …

A

Mesoderm

53
Q

When does the neural tissue know that it will become NS?

A

Gastrula phase

54
Q

Does the involuting mesoderm responsible for neural tube induction become a part of the NS?

A

No. It disintegrates.

55
Q

Noggin

A

the first neural inducer identified

Noggin was capable of specifically inducing neural genes, without inducing mesodermal genes.

Works by disinhibiting neuron formation.

56
Q

Follistatin, Chordin

A

Inhibits TGF-beta along with Noggin. Works by disinhibiting neuron formation.

57
Q

What is the chemical that adjacent cells use to inhibit neuron formation?

A

BMP induces epidermal cell lines by activating Smad second messenger.

58
Q

What gene is responsible for neural induction?

A

bHLH genes
basic Helix-Loop-Helix transcription factors

Remark: in chicks, the ligand responsible for activating these genes is FGF