Lecture 17 - Grow A Brain

Question 1

What are the 7 key processes that occur during brain development?

Answer 1

1. Neural induction (template)
2. Formation of the neural tube (template)
3. Regionalisation (template)
4. Neurogenesis & migration (template)
5. Axon guidance (wiring it up)
6. Refinement of projections (wiring it up)
7. Plasticity (wiring it up)

Question 2

What is NEURAL INDUCTION?

Answer 2

How the stem cells get told their fate

Question 3

What forms the PNS? What forms the CNS?

Answer 3

PNS = neural crest cells
CNS = neural tube

Question 4

When does the caudal end of the neural tube close? What is it called when it doesn’t close?

Answer 4

26-28 days. Spina Bifida (less severe).

Question 5

When does the rostral end of the neural tube close? What is it called when it doesn’t close?

Answer 5

24-26 days. Anencephaly (no brain)

Question 6

When the neural crest differentiates it goes from __ ventricles to __ ventricles. What does each of the ventricles turn into?

Answer 6

3 –> 5 (1a, 1b, 2, 3a, 3b)
1a & 1b = forebrain
2 = midbrain
3a & 3b = hindbrain

Question 7

During neural induction, bone morphogenic protein is sent out from the ectoderm. What signals are sent where to form the rostral neural plate, caudal neural plat & epidermal epiderm?

Answer 7

BMP –> epideral epiderm
BMP inhibitor –> rostral neural plate
Posteriorising agent e.g. retinoic acid –> caudal neural plate.
From here divided into smaller and smaller subunits called neuromeres.

Question 8

What are the medial/ventral signalling protein?

What is the lateral/dorsal signalling protein?

Answer 8

m/v = sonic hedgehog (Shh)
l/d = bone morphogenic protein (BMP)

Question 9

What is an example of plasticity?

Answer 9

Ocular dominance plasticity