Brain Development Flashcards
Which germ layers leads to the formation of the nervous system and the skin?
The ectoderm
When does the brain begin to form?
At three weeks of development
What is the neural plate?
Tissue from the ectoderm that goes to form the nervous system. It first folds in on itself to form the neural tube.
What is the role of somites?
Protection of the notochord and the spinal cord.
What determines the fate and position of the cell?
Chemical compounds called morphogens and their concentration. They are secreted by the notochord.
What are the 6 processes of neural development?
- Proliferation
- Migration
- Aggregation
- Differentiation
- Circuit formation
- Pruning and programmed cell death.
When does myelination occur?
Following synaptic pruning
What is neurogenesis?
Neural proliferation
What is symmetric division in terms of neuronal proliferation?
Cortical progenitor cells divide two produce either two progenitor cells, which predominate during earlier stage of neurogenesis, or two new neurons, which occur during later stages of neurogenesis.
Where does proliferation occur?
In the ventricular and subventricular zones
What are the two types on neural migration?
Radial migration and tangential migration.
What is radial migration?
Ventricle neural precursors climb up the radio glial cells to the dorsal surface of the cortical plate. Those that arrive first form the inner layer (5).
What is tangential migration?
Neurons from the ganglion eminence migrate freely to the dorsal surface of the cortical plate where they become interneurons.
How is the axon formed and stretched out during polarisation of the neuron?
Morphogens aid polarisation. Chemo-attractants and chemo-repellents guide the axon to stretch in the appropriate direction.
How are synapses formed in terms of the chemo-attractant process?
Presynaptic and postsynaptic proteins attract each other to form synapses.
