Developmental Neurobiology - making the embryo

BMP in organisers

Causes epidermal differentiation

Chordin and Noggin

Antagonise BMP, secreted from organiser cells to cause neural differentiation

Gastrulation

Embryo becoming multi-layered

Invagination

Cells bend inwards

Ingression

Cells migrate away

Involution

Cells roll under to make another layer

Wnt in gradients

Expressed posteriorly, high = spinal chord, low = brain

Dkk

Wnt antagonist

Hox

Different homologs pattern the spinal chord

Neural plate boarder

Eventually becomes neural crest cells and roof/floor plate

Neural crest formation

BMP causes Msx expression, leading to transcription of genes giving the cells a neural crest identity, these either migrate away or stay to close the neural tube

Shh

Morphogen inducing different cells along the d-v axis

Notch/delta signalling

Delta activating Notch in another cell causes less achaete-scute proteins which normally activate Delta, these either migrate cells fight to see who will be neural