Plasticity And Regeneration

Question 1

Gene expression depends on what?

Answer 1

Inducing factors

Competence- ability to respond to factors (transduction molecules)

Question 2

Neurogenesis happens between:

Answer 2

5th week- 5th month of gestation

Question 3

Peak rate of neurogenesis?

Answer 3

250,000 per min

Question 4

Neural progenitor cell?

Answer 4

Incapable of self renewing

Give rise to one class

Question 5

Asymmetrical division gives rise to…

Answer 5

Neuroblast and progenitor cell with limited mitotic potential

Question 6

Balance of numb and notch causes?

Answer 6

2 neural stem cells

Question 7

Unequal distribution numb and notch 1 leads to?

Answer 7

Neuroblast with all notch 1 and progenitor cell with numb

Question 8

Neuroblast Migrating neuron pends on factors?

Answer 8

Age of precursor cell, position in ventricular zone, environment at time of division

Question 9

How do neuroblast differentiate?

Answer 9

Growth cone and filopodia

Question 10

Differentiate conditions?

Answer 10

1. Pathway selection e.g. retinal ganglion cell reaching the correct thalamic location.
2. Target selection
   e. g. selecting the appropriate thalamic nucleus, LGN.
3. Address selection
   e. g. which LGN layer.

Question 11

Chemoattractant?

Answer 11

Netrin

Question 12

Chemorepellent?

Answer 12

Slit

Question 13

Time window for optimal development?

Answer 13

Critical periods

Question 14

Conditions for Successful completion of critical period?

Answer 14

1. Availability of Appropriate influence

2. Neural capacity to respond

Question 15

Peripheral regeneration?

Answer 15

Injury to peripheral nerve causing macrophages to remove myelin debris.

Schwann cells produce growth promoting signals, neurotrophic

Parent neuron expresses genes that restore it to a growth state, and allow it to respond to factors provided by Schwann cells

Question 16

Places of neurogeneration?

Answer 16

Hippocampus (primarily interneurons)

,subventricular zone to olfactory bulb

Question 17

Barriers to regeneration?

Answer 17

1. Not enough neurons
2. No radial glial cells for scaffolding
3. No migration
4. Hostile environment for repair/regeneration
5. No new interneurons, no interneurons progenitors

Question 18

Dividing precursor cells stages?

Answer 18

In G1- nucleus is near ventricular surface

During s stage, nucleus and surrounding cytoplasm migrate towards pail surface and DNA replicates

During G2- cell grows and nucleus migrates towards lumen again

In mitosis cells lose their connection to pial surface and divide.

Question 19

What is a neuroblast?

Answer 19

Post mitotic, immature nerve cell that will differentiate into a neuron.

Question 20

Where are Hsiang and neutron secreted?

Answer 20

Ventral midline of the spinal cord

Question 21

Why do critical periods end?

Answer 21

Axon growth?
Synaptic transmission matures?
Constraint cortical activation

Question 22

Central nerve regeneration?

Answer 22

Injury to nerve, causes degeneration of myelin and other elements, microglia come to clear debris, local production of inhibitory factors by astrocytes oligodendroglia and microglia and glial scar formation