Neurogenic Development Flashcards
when does the human brain begin its development?
3rd post conception week
what are the periods of brain development?
embryonic period
fetal development
post natal development
adolescent brain
how long does the embryonic period of brain development last?
until gestational week 8
what are the two layers of the embryo?
epiblast
hypoblast
igration of cells in an embryo is determined by what?
nodal signalling
embryonic cells migrate through what?
primitive streak
then rostral caudal migration
what are the three layers of an embryo?
ectoderm
mesoderm
endoderm
ectoderm layer gives rise to what?
skin
nails
hair
neural tissue
mesdoerm gives rise to what?
muscle
bone
cartilage
vascular system
endoderm gives rise to what?
gut and respirtory system
what is the first well defined neural structure to form?
when does this occur?
neural tube at day 20-27
what condition occurs if the neural tube does not close properly?
spina bifida
what lines the inside of the neural tube?
neural progenitors
the hollow centre of the neural tube is termed what?
the ventricular zone
the rostral/caudal tube will become the brain
rostral → brain
caudal → spinal cord
name the three primary brain vesicles
prosencephalon (forebrain)
mesencephalon (midbrain)
rhombencephalon (hindbrain)
at what stage do the three primary brain vesicles form?
3-4 week embryo
which signalling molecules are present in the neocortex?
Emx2
Pax6
high conc of which signalling molecules in the neocortex give rise to motor neurones and which to visual cortical neurones?
high conc Emx2 → motor neurones
high conc Pax6 → visual cortical neurones
genes are expressed differently at the anterioir and posterior portions of the brain true/false?
true
what is the term used to describe the smooth contour of the brain initially?
lissencephalic
what is the name given to the folded appearqance of the mature brain?
sulcal and gyral pattern
describe the division of the neuronal progenitor cells over the fetal period?
divide symetrically in ventricular zone i.e two identical cells arise then,
asymmetrical division i.e one progenitor cell and one neuron unable to further divide
of progenitor cells and neurons which ones remian inthe ventricular zoen ans which migrate to the developing neocortex?
progenitor cells remain in ventriuclar zone
neurons migrate to neocortex
what are the three types of neuronal migration?
somal translocation- neurone moves itself
radial glial guides- follows (climbign rope)
tangential migration and sognalling- horizontal movement
what structures transmit signals from neurones?
axons
which structures gather info and transmit to neurones?
dendrites
multiple dendrites form what around a neurone?
arbors
what is the term used when brain vesicles fail to form properly?
holoprosencephaly
what are three disroders of myelination?
hypolyelination
dysmyelination
demyelination
which gene encodes the predominant myelin protien in the CNS?
PLP1 gene
