Development of Nervous System Flashcards
ectoderm becomes what during neuralation?
neural plate, from it: neural crest: from it: neural groove
How many pairs of nerves in CNS?
31 pairs
gradient of formation of nervous system?
rostral to caudal
closing events of neural fold and problems: explain
separate events, risk of one not closing:
eg. spina bifida and ancephaly
what are the 3 distinct vesicles at the rostral end of the neural tube?
prosencephalon (fore)
mesencephalon (mid)
rhombencephalon (hindbrain)
prosencephalon splits into?
telencephalon
diencephalon
rhombencephalon splits into?
7 segments
rhombencephalon splits into two others?
metencephalon: pons
myeloencephalon: medulla
where to retinae come from?
optic vesicles of the diencephalon
Dicencephalon becomes?
thalamus and hypothalamus
What happens to neural crest cells posterior to newly formed neural tube?
migrate away, form lots of structures
Neural crest cells become 4 big things:
PNS
melanocytes
muscle, bones of face/jaw
dentine
what 4 things does the neural crest form in the PNS?
dorsal root ganglia
symp and parasymp ganglia
enteric ganglia
schwann cells
migration of neural crest cells are recovered in what pathological processes?
cancer metastasis
how this is the neuroepithelium?
single cell thic
what is the ventricular zone?
where neural stem cells start, grow inside-out
Stem cells definition?
self-renewing, undifferentiated totipotent: daughter cells able to differentiate
what is radial ganglia?
process that guides a migrating neuron
What is Reelin mutation?
single protein mutation, malformed cortax
what is Lissencephaly? (DCX?)
very few neurons in brain
Fragile X causes commonly?
male autism
2 devepmental neural disorders?
schizophrenia
fragile X
somites do what?
develop muscle and bone
neurons controlling distal muscles are medial or lateral?
lateral
what does sonic hedgehog do?
induces the floorplate of neural tube to signal ‘anterior’
what does the floor plate of the notochord do?
induces ventral horn motor neurons
explain induction of interneurons
appear just dorsal to motor neurons in notochord
do new neurons have axons?
not really, grows out to meet target
how is the initial scaffold of axon tracts laid down?
single pioneering axon
How do axons grow?
via growth cone, it tows the axon without moving the soma towards its target
How do you steer a growth cone?
membrane bound signals like NGF will promote and inhibit in certain areas
What is the critical period? when can it occur?
refinement of synaptic connections that establish functional nervous system, can happen post-natally
what happened to kitten with glued eye at birth
after 6 months, it was functionally/permanently blind in that eye due to visual cortex refinement to one eye
what did the kitten’s cortex look like who had the deprived eye?
deprived: less representation
open eye: enhanced representation
does timing matter for critical period in kitten eye closing?
yes, after critical period over, no permanent changes neurally
What is relative activity in relation to critical period?
no blindness if both eyes are covered
depends on relative neural activity
How long is a human critical period?
10 years…
