Neuro4 - 14 Flashcards
How does the neural plate rolling into the neural tube affect axes?
Medio-lateral becomes dorso-ventral
What the axial mesoderm express after convergent extension?
SHh
What does SHh induce the expression of?
SHh in the ventral-most cells of the neural tube - the floorplate
What is SHh role in the neural tube?
Not to induce expression of genes - actually to suppress certain TFs, confining them to the forsal part of the spinal cord, in a nested way
What are the class 1 genes?
Pax7, Dbx1, Dbx2, Irx3
What are class 1 genes?
TFs, which act to repress other genes in the cell, so SHh repression of class 1 genes, actually activates gene expression
What do the discrete expression of TFs in the neural tube create?
Distinct progenitor gomains
What do differentiated cells do in the neural tube?
Move away from the central lumen upon differentiation
What is an I segement of neural tube?
Intermediate - neither dorsalised or ventralised
What does I neural tube express?
msx1, pax3
What does I neural tube express in the presence of SHh?
ISI1, chAT (msx1, pax3 supressed)
How do cells know their fate?
Gradients setup Cartesion grid - they know by their position in it, and the gradients they’re subjected to, hence they can all differentiate at once
Briefly outline the SHh pathway
No SHh - Gli supressed; SHh - Gli activates/de-represses
What is motor neuron disease often due to?
A fault in trophic support by astrocytic/glial cells
