Anatomy and Cell Biology 3319 Lecture Notes - Lecture 3: Neural Crest, Neural Groove, Neural Tube
1 May 2018
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Lecture 003: Development of the Brain and Spinal Cord
Embryonic development
● Brain and spinal cord is a
“rounded” structure
○ Didn’t start that way
● Started as a NEURAL PLATE
○ Flat
○ Ectoderm
○ Neuroepithelial cells
○ Becomes CNS and
neuroblast cells
● Plate has to FOLD
○ Gets the neural groove
○ This is what develops into
the neural tube
● Nerval Grove (from the ectoderm)
○ Forms the basis of the
neural system
● Neural Crest cells
○ Forms another cluster of
neurons that are very
important (separate)
○ Lies outside the CNS
○ Sensory neurons
● Fold becomes more pronounced
as time goes on
○ Eventually the fold closes
○ Becomes the neural tube
● Neural tube
○ A layer of cells that
surrounds some fluid
○ Fluid becomes the
cerebrospinal fluid
(CSF)
○ Formed from the
ectoderm
● Neural crest cells are breaking
off
Terms to keep in mind:
● Rostral (Head)
● Caudal (Tail)
find more resources at oneclass.com
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Closure occurs first in the middle of the tube
● Closure spreads in both the rostral and caudal direction until the full tube is closed
● Structure develops as cells differentiate and proliferated on the outside
○ especially on the rostral (head) end
■ massive development of structure occurring here
■ Prosencephalon
■ Mesencephalon
● Caudal (tail) end is relatively simple
○ Cell division, get a thicker layer but no mass development of structures
Anencephaly
● Disruption of the closure of the canal on the ROSTRAL end
● Both serve and minor forms
● Problems at birth (blind, deaf, unconscious)
● Have rudimentary brainstem
○ Able to support life, have cognitive issues
Spina Bifida
● Not as severe
● Difficulty in controlling limb and bowel movement
Don’t have to remember the exact days
● Only important one: neural tube forms around 22 days
How do you go from a fluid filled tube to a complex brain?
2 critical things must take place in the neural tube
● There is a development of a large collection of neuroblast cells in the dorsal and
ventral direction
○ Proliferation of cells
● Neural crest cells become the unipolar neurons (sensory)
○ These neurons have the cell bodies outside of the CNS
○ Bring information from the periphery cells
2 serious collections of neuroblasts that are differentiation into mature neurons
find more resources at oneclass.com
find more resources at oneclass.com
Document Summary
Lecture 003: development of the brain and spinal cord. This is what develops into the neural tube. Forms the basis of the neural system. Forms another cluster of neurons that are very important (separate) Fold becomes more pronounced as time goes on. A layer of cells that surrounds some fluid. Closure occurs first in the middle of the tube. Closure spreads in both the rostral and caudal direction until the full tube is closed. Structure develops as cells differentiate and proliferated on the outside. Cell division, get a thicker layer but no mass development of structures. Disruption of the closure of the canal on the rostral end. Able to support life, have cognitive issues. Difficulty in controlling limb and bowel movement. Only important one: neural tube forms around 22 days. 2 critical things must take place in the neural tube. There is a development of a large collection of neuroblast cells in the dorsal and ventral direction.
