lec 8. neurogenesis

Question 1

neuroepithelium

Answer 1

are neural stem cells which make up the wall of the neural tube (initially 1 cell thick). they divide symmetrically into 2 daughter cells which become radial glial cells

Question 2

interkinetic migration

Answer 2

position of nucleus of neuroepithelium moves as it proliferates
G1/S -> nucleus away from lumen
M/cytokinesis -> nucleus is close to lumen
cytokinesis -> lateral attachment is lost then reforms

Question 3

radial glial cells

Answer 3

progenitors that produce all neurons in the cerebral cortex
divide asymmetrically into daughter progenitor that stays in ventricular zone and neuron that uses sister as scaffold to move to mantle zone.

Question 4

what 2 things could cause asymmetric division of radial glial cells

Answer 4

1) asymmetric division of cytoplasmic determinants

2) differentially activated membrane components as through notch signalling

Question 5

proneural genes

Answer 5

makes cells competent to become neural

Question 6

proneural mutant

Answer 6

no cell becomes neural

Question 7

notch mutant

Answer 7

more than normal cells become neural

Question 8

lateral inhibition

Answer 8

1) both cells express delta and notch equally
2) cell 1 makes more delta, so cell 2 receives more delta
3) cell 2 represses expression of delta and becomes support glia
4) cell 1 notch signalling is inhibited and becomes neuron