Binary decision: Neurogenesis

Question 1

What are the fates of progenitors?

Answer 1

• Move laterally and differentiate into mature neurons in mantle zone.
• not undergo differentiation into neurons and stay in ventricular zone (central lumen)

Question 2

What happens to the neurons that do not differentiate?

Answer 2

Exist as Radial Glia (neural stem cells)

They provide a pool of undifferentiated cells that are used to build up the nervous system over time in embryogenesis

Question 3

What do we call the early neural tube?

Answer 3

neuroepithelium/neuralepithelial cells

Question 4

Progentior cells (neuroepithelium cells) that proliferate

Answer 4

Their nuclei undergo interkinetic migration.
In G1 and S phase of the cell cycle, the Nucleus is away from the lumen.
At M phase and cytokinesis, the nucleus is close to the lumen.
At cytokinesis, the lateral attachment is lost, then reforms

Question 5

How can neuroepithelial cells divide and give rise to

Answer 5

Early neuroepithelial cells can divide Symmetrically, generating 2 identical
daughters.
These start to change shape and become Radial glial-like – ie cells with a longer Process.

Question 6

How do Radial Glia divide and what do they give rise to

Answer 6

Radial glia can divide asymmetrically, giving rise to one daughter which is like its mother – ie a radial glia (stem cell), and a 2nd daugher that will differentiate to a neuron. This daughter uses the scaffold provided by its sister to migrate away from the ventricular zone