KD - Differentiation and Migration

Question 1

What happens when there is a lack of shh? (2)

Answer 1

• Optic vesicles generated on dorsal side
• Shh inhibition/loss leads to loss of ventral identity

Question 2

What are known as neural precursor cells?

Answer 2

Neuroepithelium/Neuroepithelial progenitor cells in neural tube

• Form the ventricular zone

Question 3

What acts to connect the ventricular and pial surface?

Answer 3

Radial glia

Question 3

How do radial glia and precursors divide?

Answer 3

Radial glia divide slowly and symmetrically

Precursors divide asymetrically

Question 3

Where do neuroblast cells migrate? (3)

Answer 3

1. Neuroblast migrate to pial surface
2. Form the marginal zone
3. Differentiate into neurons

Question 3

How is the cortex built?

Answer 3

Inside out
- Newer neuroblasts migrate past their older cousins

Question 4

Where are glia cells generated from?

Answer 4

Neuroepithelium

Question 5

What do glioblasts differentiate to?

Answer 5

• Either remain attached to lumen and become ependymal cells (production of CSF)

or

• Move to the marginal layer and form astrocytes (maintenance and repair) or oligodendrocytes (myelination)

Question 6

What is the origin of interneurons, and how do they migrate?

Answer 6

Interneurons are born in the ganglionic eminences and migrate tangentially

Question 7

How is polarisation in growing neurites achieved?

Answer 7

Neurites grow out to establish axons and dendrites.

Question 8

Why is target innervation important for brain function?

Answer 8

Brain function depends on correctly wired circuits, which require highly ordered structures for proper function

Question 9

How do growing processes navigate through the embryonic body?

Answer 9

Growing processes use cues and signals to navigate from one point to another and may “piggyback” or fasciculate along the way