Developmental neurobiology Flashcards
briefly describe gastrulation
the epiblast forms 3 layers - ectoderm (neural plate), mesoderm (notocord) and endoderm
which germ layer does the nervous system arise from
ectoderm
describe neural induction
the neural plate border has a bunch of signals.
as neurulation is forming, the signals converge, inducing cells in the neural plate to become neurons, and the non-neural ectoderm cells to form the epidermis
describe neurulation
the neural plate folds, forming the neural tube. it zips inside out to close
-if it doesnt close properly, neural tube defects can occur
describe neurogenesis
pial surface: synthesis
apical surface: everything else
symmetrical: one APC forms 2 APC’s
asymmetrical type I: when two new cells are made, one turns into an APC, the other turns into a neuroblast than a neuron
asymmetrical type one: as with before, but before turning into a neuroblast it forms a basal progenitor cell
describe neuron migration
neuroblasts climb up APC’s, and then are distributed into the cortex as neurons. newer neurons are distributed outside
describe neuron patterning
different parts of the neural tube swell to become ventricles, which form different parts of the brain (fore/mid/hind)
signals/growth factors occur in different places. leading to formation of different neuron patterns
describe axon guidance
growth cone
- receptors:bind to environmental ligands, which can influence growth cone growth
- cues may be repulsive/attrctive, contact/distance
describe synaptogenesis
requires two neurons to make contact, for contact to be stabilised by cell to cell interactions, and for the neuron to be sufficiently mature (ie. have machinery)
-modulated by use of syanpse
describe dendritic growth
- length increases after birth
- pyrimidal has one apical dendrite and multiple basal
when does gliogenesis occur
after neurogenesis
where do astrocytes and oligodendrocytes come from
neural plate
where do microglia come from
immune system
where do schwann cells and satelite cells come from
neural crest cells.
describe how neural crest cells form
neural plate border cells induced to become neural crest cells
