Development of the CNS Flashcards
What is anacephaly?
Failure of closure of the neural tube in zone 2 (across the skull) resulting in stillborn
What is spina bifida?
Failure of closure of zone 5 of the neural tube
What are the 3 vesicles that the neural tube initial expands into?
prosencephalon, mesencephalon and rhombencephalon
What does the prosencephalon divide into?
the telencephalon and the diencephalon
What structures in the mature brain make up the telencephalon?
the cortex, basal ganglia and hippocampus
What structures in the mature brain make up the diencephalon?
the thalamus and hypothalamus
How many segments does the rhombencephalon divide into?
7
What does the rhombencephalon split into and what do these structures become in the mature brain?
metencephalon (pons and cerebellum) and myeloencephalon (medulla)
What does the mesencephalon become?
the midbrain
What is the ventricular zone?
the ventricular surface of the cortex which contains stem cells from which the layers of the cortex will develop
What guides the migration of neurons in the cortex?
radial glia
Mutations in which genes can lead to a malformed cortex due to an inability to migrate?
reelin and DCX
What determines the development of the organisation of the spinal cord?
The notochord releases signalling molecule which forms a gradient so that the area closest to the notochord will develop as the ventral part of the spinal cord (initially called the floor plate)
What controls where axons grow?
growth cones - a cytoskeleton structure which follows chemical gradients to drag the axon into place
