When do neural cells become determined?

Question 1

are cells already determined at the ventricular zone?

Answer 1

-if they were, all cells would be the same type of cell
-if they weren’t determined, cells would be different, which is what happened

Question 2

where do cells become determined?

Answer 2

in their final location
-due to local paracrine factors

Question 3

Le Dourarin experiment

Answer 3

transplant quail neurons into chick and switched their location
-they switched based on environmental indicators

Question 4

How does the environment tell cells where they are?

Answer 4

-concentrations of compounds, gradients

Question 5

gradient of retinoic acid

Answer 5

-high levels: repress anterior Hox, activate posterior Hox genes
-low levels: activate anterior Hox genes

Question 6

how does noggin induce anterior neural cells?

Answer 6

-treatment with FGF converts them to posterior neural cells (sufficient to posteriorize)
-dominant negative that inhibits FGF signaling->results in anterior neural cells, shows that FGF is necessary to posteriorize neural cells

Question 7

How does the notocord impact neural tube fate?

Answer 7

-transplanted notocord resulted in ectopic motor neurons and floor plate
-indicating diffusible soluble factors from the notocord tell cells how to differentiate