Flashcards in Neuro Development Deck (59):
First, the brain establishes__?
distinct brain regions
second, the neuroprogenitor cells differentiate to?
neurons or glia
much of the brain development is during
the first trimester
when does myelination begin?
postnatally... remember babinski sign in babies
four expansions of the neural tube
prosencephalon, mesencephalon, rhombencephalon, spinal cord
prosencephalon separates to make __ and __
telencephalon and diencephalon
rhombencephalon separates to make __ AND __
telencephalon becomes what three things
paleocortex, corpus striatum, neocortex
diencephalon becomes what four things
epithalamus, thalamus, hypothalamus, indifundibulum
mesencephalon becomes what three things
tectum, tegmentum, cerebral peduncles
rhombic lip significance
lip of the hindbrain; this is where the cerbellum begins to develop
roof of midbrain
REMEMBER: neural plate makes two parts
the neural crest and the neural tube
name a few things that are responsible for the molecular signals that induce cell and tissue differentiation
notochord, somites, ectoderm, and floorplate
what is the floorplate?
it is the ventral section of the neural tube (the side that is close to the notocord) it apparently guides the motor neurons to the correct location
lamina terminalis is from what part of the embryo
anterior part of the neural tube that zips together
name the three flexures during the developing brain
cephalic flexure, pontine flexure, cervical flexure
name of brain segments
rhombomeres!! little clumps of the nervous system
does everything come from a rhombomere?
nope. but usually in the neural tube, and especially in the medulla. these little areas have their own little nerves and pathways that develop from them.
what is the adult result of rhombomeres
you can see the trigeminal, facial, glossopharyngeal nerves come out and clump together. this is because of the rhombomeres
area that separates the alar and basilar plates
what is the roof plate?
that is the dorsal plate of the neural tube; it separates the left and right alar plates
there is a neural tube and pial surface with neurons in between. where does the neuroblast divide?
near the neural tube.
how would you study where a neuroprogenitor cell goes?
you can use birthdating. inject them with a marker and see where they go. if the cell keeps dividing, you won't see them as well, but if they stop dividing, then you will very clearly see where they are.
what layer of the cortex is the newest/freshest
in the telencephalon, its the cortex, layer 1. in the diencephalon, its opposite
what kind of glial cell comes from neural crest
what glial cell helps the neurons migrate?
radial glial cell
anencephaly/merocephaly is from?
defect in the anterior neuropore (adult lamina terminalis)
filure of midline cleavage of embryonic forebrain; in trisomy 13, can be associated with fetal alcohol syndrome and agenesis of corpus callosum
herniation of cbellar tonsils into the foramen magnum; crushes the developing medulla and can cause a cavitation of the medulla
syringomyelia and syringobulbia
"bulbar" refers to brain stem. look up specifics
this is a posterior neural tube defect
neural crest cells can become
melanocytes, connective tissue, pseudopolar ganglia of spinal and cranial nerves, chromaffin cells (adrenal medulla), peripheral glia, leptomeninges, multipolar ganglion cells ans
embryonic origin of chorioid plexus
blood born mesenchymal tissue that goes to the brain
REMEMBER: what will a somite become
has a dermatome part (skin); scelerotome (vertebrae); and myotome (muscles)
what does a placode have to do with placode
ectoderm that mixes with neural crest cells to become cranial nerve ganglia
ventricle of prosencephalon
agenesis of corpus callosum; cerebellar aplasia; enlarged 4th ventricle; from riboflavin inhibitors, posterior fossa trauma or viral infection
internal capsule is always between??
thalamus and basal ganglia. even during development
once the brainstem splits open, what happens to the alar plate?
it moves laterally
CNs with GVE
3, 7, 9, 10.
embryonic origin of substantia nigra
direction of diencephalon development
the first cells born, ride the radial glial cell to the farthest edge of the diencephalong. this directionality is opposite from the telencephalon
tangental migrations involved in
cortex develoipment; usually these cells are GABAergic
gyri fail to form in cerebral cortex; smooth brain surface
disrupted migration of cerebral cortex
influences detachment of a newly born cell from a radial glial cell
flexure of the rhombic lip
three layers of the cerebellum
the inner layer is the inner granular layer; then is the purkinje cells, then is the molecular layer
where does the internal granular layer come from
originally it is a layer of cells from the midbrain. they cover the cerebellum and then the cells jump on the radial glial cells and migrate INWARD.
where do the purkinje cells come from
they are made in the ventricular zone and then they get on the radial glia and migrate OUTWARD;
a tumor because the granular cells are never turned off
netrin vs semaphorin
netrin is attractive to axons; semaphorins are repulsive
beaded axon is
usually its an axon that expresses peptides; it has tons of synapses along the axon
when are neurons programmed to go to a certain location?
before they even leave, they know where to go
you produce synapses during ____; and you get rid of the unneccessary ones during ____
development and childhood; teen years
trophic factor regulates what three steps
1) match the number of neurons to the available space on the target
2) make sure that the pre and post synaptic neurons match NT types)
3) stabalized the connections between axon and the target
climbing fiber relationship to purkinge fibers
there is only ONE climbing fiber per purkinje fiber