cortex development Flashcards
what happens if the one cell thick neural tube doesn’t turn into the multiple layered cortices of the cerebrum and cerebellum?
you get developmental abnormalities suchas lissencephaly (smooth brain) and migration problems
how do the neural tube cells divide?
by nuclear translocation
when does the neural tube’s cell division take place?
when the nucleus is at the inner surface, in the ventricular zone
how can you identify the marginal zone?
it’s relatively cell body free
why can it look as if the neural tube is made up of multiple layers?
because the cell bodies can shuttle up and down (not into marginal zone though)
when does cell division rate increase?
when the neuropores close
what is a neuropore?
they’re the pores at the end when the flat sheet forms a neural tube
when the cerebral cortex is forming how is the pre-plate formed?
from post-mitotic cells moving from the ventricular zone to start forming the pre-plate
which cells in the marginal zone move off first?
the cajal-retzius cells
what is formed under the cajal-retzius cells?
the subplate
where does the cortical plate form?
what does this split?
under the marginal zone, above the intermediate zone.
splits the preplate and form many layers of the adult cortex
how can you tell that the cajal-retzius cells are making lots of proteins?
because there’s lots of RER and also the chromatin in the nucleus is making lots of mRNA
what do cajal-retzius cells secrete?
Reelin
what is reelin?
made up of 3460 AAs and is ECM like
what happened in Reeler mice studies?
the preplate formed but the cortical layers were malformed, showing parralels to lissencephaly
what is cajal-retzius cell development regulated by?
Foxg1
what is seen in a Foxg1 -/-?
too many cajal-retzius cells, the cells are being made but aren’t migrating properly.
how can cell birthdays be found? how does this work and what does it show?
using 3H-thymidine to incorprate into DNA on cell division, injected into female mouse at different stages of dev, can see the different parts. the earlier on in dev the closer the cells are to the ventrical margin.
question about cortical layer conufdj
look at this on echo thing
more question
echo check
one more
do this!!
what is cell migration usually associated with?
radial glia
how do cells move radially?
cell body at the inner space and then send processes to the outer space
is all migration radial?
no some can move tangially
what markers do radial glia have? what happens to these during dev?
astrocyte markers, these disappear after development as they are no longer needed.
what kind of cells are the glia?
they are stem cells
do all the radial glia disappear?
no the bergmann glia cells of the cerebellum don’t this could be due to the cerebellums late development
where does the cerebellum form?
at the roof of the 11th ventricle
what is the cerebellum consist of?
the cortical region and the central nuclei (deep cerebellar)
what is the cortical layer made up of?
the molecular layer
purkinje layer
granule layer
white matter
where does the cerebellum form?
at the boundry of the mid and hind brains
what’s characteristic about the roof of the 4th ventricle? what does this mean for the ventricular zone?
it’s very thin, the VZ is very close to the surface when it’s usually deep within, the cells on the inside are very close to the outside.
where are the rhombic lip cells?
at the superior and inferior edges of the medullary velum
what happens to the very thing roof of the 4th ventricle on embryonic14-16, E17, then what happens?
the roof starts to bend in, cells start to appear on the outer surface, then more cells and this continues to happen until the cerebellum is formed.
what do the superior rhombic lip cells form?
the external germinal layer
what produces all other cell types of the cerebellum?
the ventricular zone
what does the inferior rhombic lip produce?
the pontine nuclei and inferior olive
what does the External germ layer produce? what do these then do?
it produces granule cells (neurons) these then migrate inwardly.
what happens as granule cells increase and what starts to appear?
the cerebellum’s mass increases and folia appear
what regulates the production of rhombic lip cells? what is this?
MATH-1, this is a transcription factor
what happens if there’s no MATH-1?
there’s no foliation, no internal germ layer and no pontine nucleii in the cerebellum
what do purkinje cells release and what does this stimulate?
Shh, stims mitosis in the external germ layer
what happens to the layers in the cerebellum in reeler mice?
they have disordered layers
where is reelin synthesised in the cerebellum?
in the external germ layer
