Development of Brain Flashcards
2 weeks the increased number of cells and movement of the cells toward and along the midline result in…
gastrulation
(formation of the 3 layers, endoderm, mesoderm and ectoderm)
- forms the nervous system
- as it thickens, it becomes the neural plat e, then the neural groove (this becomes midline of the embryo)
ectoderm
tops of the neural ridges join together forming the…
- this becomes the cerebral ventricles, central canal of the spinal cord and passages that connect them
neural tube
the anterior part of the neural tube forms the three subdivisions…
the forebrain, the midbrain and the hindbrain
mitosis produces neurons from non-neuronal cells
neurogenesis
cells move out of the ventricular zone (where they are produced) toward their destination, where they will become different brain regions
cell migration
cells become distinctive types of neurons (depending on their location and function) or through cell-cell interactions; this increases of the system because of different cells can fill in as needed
cell differentiation
establishment of billions of synaptic connections
synaptogenesis
selective death of many neurons (in some areas, nearly half the cells born will die!)
cell death
- to ensure there are enough
- better to make a bunch at once than have to make more later
why make extra cells if you’re just going to kill them off?
loss or development of synapses, fine-tuning (also called synapse elimination, or pruning); this continues throughout life
synapse rearrangement
is an important part of brain development
- isn’t haphazard and random; it’s highly regulated and there are a lot of checks and balances
cell death (apoptosis)
neurons compete for…and… (things that keep them alive)
synaptic connections and neurotrophic factors
cells that don’t receive the … will actually turn on certain genes (death genes) that programmatically break them down
neurotrophic factors
ones that don’t receive enough trophic factor from their target
which cells die?
