Lecture 7 Development Flashcards
How long does it take for cellular division to begin after conception
12 hours
What are the six stages of prenatal neural development
1) Neurogenesis
2) Cell migration
3) Cell differentiation
4) Synaptogenesis
5) Cell death
6) Synaptic rearrangement
What are the 3 layers formed during gastrulation called, what do they turn into.
Ectoderm: Outer surfaces, skin/hair
Mesoderm: Skeletal, smooth muscle, cardiac
Endoderm: Stomach, liver, internal organs
What is the first stage of brain development, how does it happen?
Development of the neural plate is the first stage of brain development. The mesoderm sends chemical signals to the ectoderm, which causes the ectoderm to thicken and become the neural plate
What happens to the neural plate at 20 days?
the neural groove starts to develop from chemical signals from the mesoderm
When looking at the flattened neural groove which row develops into what type of neuron?
The most lateral(outside) row gives rise to sensory neurons.
The middle row gives rise to interneurons.
The medial(inside) row gives rise to primary motor neurons.
What developments occur at day 22?
crests of the neural groove come together to form the neural tube
What developments occur at day 25?
The anterior part of the neural tube forms the forebrain, midbrain, hindbrain
Describe what occurs during neurogenesis
Formation of the neural tube and the production of neurons occur
The inner area of the neural tube (used to be the neural plate) is where new neurons are created
Describe the Cell migration period of prenatal neural development
Cells migrate to their final position either using somal translocation(short range) or glial mediated migration(long range)
somal translocation:
A probe (filopdia) extends out of the cell which is attracted or repelled by chemical signals which then pulls the cell along
Glial-mediated:
cells move along radial glial network that extend from the inner to outer layers of the brain
Describe the cell differentiation process
Once the cell is at its required location cells communicate to others via Cell-Adhesion Molecules, which can help identify what type of cell a cell is. Depending on what the cells around it are doing and what is in need the cell differentiates to fill the required role.
Describe synaptogenesis and its processes
The development of functional connections between neurons. Both genetics and experience contribute to this process
What was Roger Sperry’s Synaptogenesis experiment?
Inverted the eye of a tadpole
Frog performed inverted movements, suggesting that information for perception of “up /down/right/left”) was
genetically coded.
What is Apoptosis
apoptosis is cell death during brain development, these cells die so the appropriate/well connected neurons can be properly supported as only so many can be supported due to the limited supply of neurotrophins.
Describe the process of rearrangement during neural development.
Synapses are typically overproduced in the young brain. this allows greater plasticity of the young brain. In efforts to reduce noise amount of synapses are reduced and present synapses begin to refine
