Neurodevelopment

Question 1

Neurulation

Answer 1

Formation of the CNS

Question 2

Neuroepithelial cells

Answer 2

Line the ventricles throughout the CNS and form the ventricular zone -> early precursors for neurons and glia

Question 3

At later stages neuroepithelial cells give rise to

Answer 3

Radial Glia

Question 4

Radial Glia remain within the _______ but their processes extend to

Answer 4

Ventricular zone, pial surface

Question 5

Neuroepithelium can be subdivided into several

Answer 5

progenitor domains -> give rise to different types of neurons

Question 6

Progenitor domains can be identified by

Answer 6

Specific marker genes

Question 7

Where do oligodendroyctes originate from?

Answer 7

The first oligodendrocytes originate from the pMN domain in the spinal cord which generated motor neurons then switched -> VZ precursor cells

Question 8

Immature oligodendrocytes

Answer 8

1. Elaborate morphology
   2/ Express O4 markers
2. Limited proliferative capacity

Question 9

Mature oligodendrocytes

Answer 9

1. Express GC markers

2. Ensheath and myelinate axons

Question 10

What happens when a oligodendrocyte process makes contact with an axon?

Answer 10

1. Stimulates differentiation -> reciprocal interactions
2. Initiator processes extend and spiral along axon
3. Ensheath multiple axons

Question 11

What happens during remodeling and maturation?

Answer 11

1. Non-ensheating processes are lost
2. Initial ensheathments are uncompacted
3. Oligodendrocyte sheath wraps interact and fuse with one another to produce compact myelin
4. The myelin sheath grows longitudinally
5. Nodes of Ranvier develop

Question 12

In a myelinated axon, voltage gated channels are only present

Answer 12

at the Nodes of Ranvier

Question 13

Oligodendrocyte development

Answer 13

1. Originate from neuroepithelial precursor cells
2. Generated as proliferating precursors that migrate away from VZ to populate developing CNS
3. Several steps of differentiation and maturation to become myelinating glia
4. Some oligodendrocyte precursors present in adult CNS

Question 14

Astrocyte development

Answer 14

1. Generated from radial glial cells during embryogenesis

2. Some astrocytes are generated by transformation of radial glia at the end of neurogenesis