● Basic processes: neurogenesis and migration, synaptogenesis, myelination, and synaptic
pruning
● Neuroclosing (day 24-28); if the frontal (anterior) neuropore doesn't close what fetus
ends up with is anencephaly; frontal brain doesn't develop so in general these babies get
terminated by the body; it is not a survivable condition; rare that they can survive
● Posterialpore not closing is called spina bifida; visible with a prenatal scan, when nerves
supposed to be going to your legs just goes to your back instead (tailbone cyst); this
means this is the nerves that is going to run your lower half and so this can result in poor
mobility in lower body; can sometimes do operation on infant in utero so a kid end up in
better mobility; could be paralyzed, depends on how much spinal nerves are in the wrong
place and stuck
● Agyria = no gyri
● Lissencephaly: due to defective neuronal migration; genetic, vira, hypoxia during 1st
trimester; you have defective migration, you dont get more and more neurons going to
the outside of the cortex so you don’t get that folding of the cortex; you have less brain
surface and will have intellectual disability; pretty rare but it does happen bc of the
migration not happening
● Microcephaly: descriptive term meaning small head circumference; will measure the
circumference of babies’ head because it needs to increase at a certain rate; in the news
big time because of zika virus; a mosquito borne virus, in Brazil getting a lot of babies
with microcephaly, went from 150 a year to 3500 a year
● 7 Basic CNS parts: spinal cord (most caudal part of tube), medulla oblongata, more
rostral is the pons (called the bridge), cerebellum (means little brain and it connected to
brain stem with fiber tracks), midbrain (it has sensory and motor functions), thalamus and
hypothalamus, two hemispheres biggest parts (contains the cortex and the white and gray
matter)
● Meninges is not the brain, it is membranes that protect the brain (CNS); dura mater: outer
layer, tough mother; arachnoid - middle layer, spider membrane, overlies the
subarachnoid space (“sub” means under, so does “hypo”), contains blood vessels; pia
mater: inner layer, overlies every detail of the outer brain
● Dura is thick and generally follows the brain; dura folds and ‘divides’ the brain into
hemispheres and separates cerebrum from cerebellum; cerebellum tent and separates the
hemispheres from the cerebellum
● Cerebrospinal Fluid (CSF): contained within four brain ventricles (CSF build up can
result in hydrocephalus) and the subarachnoid space; the ventricles are cavities within the
space, subarachnoid space is space outside the brain; produced by the choroid plexus of
the ventricles (ependymal cells); happens everyday and you produce about a pint (450ml)
of CSF per day; the whole system can only hold 150ml, so the CSF circulates and is
mostly produced in lateral ventricles and also somewhat produced in 3rd and 4th
ventricle, from the 4th ventricle there are little holes that give them access to the
pruning
● Neuroclosing (day 24-28); if the frontal (anterior) neuropore doesn't close what fetus
ends up with is anencephaly; frontal brain doesn't develop so in general these babies get
terminated by the body; it is not a survivable condition; rare that they can survive
● Posterialpore not closing is called spina bifida; visible with a prenatal scan, when nerves
supposed to be going to your legs just goes to your back instead (tailbone cyst); this
means this is the nerves that is going to run your lower half and so this can result in poor
mobility in lower body; can sometimes do operation on infant in utero so a kid end up in
better mobility; could be paralyzed, depends on how much spinal nerves are in the wrong
place and stuck
● Agyria = no gyri
● Lissencephaly: due to defective neuronal migration; genetic, vira, hypoxia during 1st
trimester; you have defective migration, you dont get more and more neurons going to
the outside of the cortex so you don’t get that folding of the cortex; you have less brain
surface and will have intellectual disability; pretty rare but it does happen bc of the
migration not happening
● Microcephaly: descriptive term meaning small head circumference; will measure the
circumference of babies’ head because it needs to increase at a certain rate; in the news
big time because of zika virus; a mosquito borne virus, in Brazil getting a lot of babies
with microcephaly, went from 150 a year to 3500 a year
● 7 Basic CNS parts: spinal cord (most caudal part of tube), medulla oblongata, more
rostral is the pons (called the bridge), cerebellum (means little brain and it connected to
brain stem with fiber tracks), midbrain (it has sensory and motor functions), thalamus and
hypothalamus, two hemispheres biggest parts (contains the cortex and the white and gray
matter)
● Meninges is not the brain, it is membranes that protect the brain (CNS); dura mater: outer
layer, tough mother; arachnoid - middle layer, spider membrane, overlies the
subarachnoid space (“sub” means under, so does “hypo”), contains blood vessels; pia
mater: inner layer, overlies every detail of the outer brain
● Dura is thick and generally follows the brain; dura folds and ‘divides’ the brain into
hemispheres and separates cerebrum from cerebellum; cerebellum tent and separates the
hemispheres from the cerebellum
● Cerebrospinal Fluid (CSF): contained within four brain ventricles (CSF build up can
result in hydrocephalus) and the subarachnoid space; the ventricles are cavities within the
space, subarachnoid space is space outside the brain; produced by the choroid plexus of
the ventricles (ependymal cells); happens everyday and you produce about a pint (450ml)
of CSF per day; the whole system can only hold 150ml, so the CSF circulates and is
mostly produced in lateral ventricles and also somewhat produced in 3rd and 4th
ventricle, from the 4th ventricle there are little holes that give them access to the
