BIOL 303 Lecture Notes - Lecture 4: Neural Crest, Neural Tube, Radial Glial Cell
14 May 2018
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Biol 303 March 20th
Review – formation of different cell types in the brain
• Cell division in ventricular zone is followed by long distance migration along the radial
glia → furthest region is the cortical plate
• While cells are still undergoing migration, they are called neuroblasts because they have
not yet matured into a specific type of neuron
• Neurons allow for communication in the brain via their synapses
• A euros target ould e aother euro or a usle ell
• Dedrites futio is to reeie sigals fro other euros
• Oligodendrocyte: main function is to insulate the axons of neurons to prevent the loss of
electric signals
• Astrocyte: function is to provide nutrients and oxygen to the brain → have processes
that oet to the euros sapse ad the lood essels, rigs utriets ad oge
from the blood to the neurons
• Astrocyte 2nd function: regulate neuronal communication → interacts with the terminal
of the neuron to modulate the communication between two neurons
• Microglia: are immune cells, main function is to destroy pathogens in the brain
• All of these cell types in the central nervous system ^ come from the neural tube EXCEPT
the microglia, which comes from the embryonic yolk sac
Development of the nervous system II
• Neural crest cells and their migration
Neural crest cells
• The dorsal portion of the ectoderm becomes morphologically different from the
neighbouring ectoderm
• After the neural fold is created and separation of the neural tube occurs, neural crest
cells are left between the new surface ectoderm and neural tube
• Neural crest cells give rise to the peripheral nervous system → sensory neurons,
sympathetic neurons
Origin of neural crest cells
• Epithelial to mesenchymal transition
• N-cadherin brings cells together during neural tube formation → increase in cell
adhesion
• For the neural crest cells to migrate away, you have to reduce their adhesions and
improve their migratory properties
• Neural crest cells are located at the top of the neural tube and stay above the neural
tube throughout the body for the rest of development
• Neural crest cells are divided into cranial, cardiac, and trunk, vagal, and sacral neural
crest cells
• Today we will focus on the migration of trunk neural crest cells
find more resources at oneclass.com
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Document Summary
Development of the nervous system ii: neural crest cells and their migration. Somites: the block structures along the body (look like red bricks) are called somites, which are blocks of mesodermal structures, on either side of the neural tube are these structures called somites. Nccs leave and give rise sympathetic ganglia: dorso-lateral migration nccs become skin cells. Other types of migration: dorso-lateral migration, ventral migration. If ncc cells come to the anterior region, they come right in. In vitro, if you have neuropilin-2 on nccs and add semaphorin 3f, you get a repulsive signal so regions where semaphorin 3f is present pushes nccs out of it. In sepaphorin 3f mutants, the neural crest cells can now go to the posterior region. In neuropilin-2 mutants, ncc migration is also disrupted. In the growth cone are sensorimotor structures that have 1) receptors that detect the guidance cues and 2) intracellular machinery that can convert signals into directed motility.
