PSYC 2012 Lecture Notes - Lecture 12: Neural Crest, Microcephaly, Lissencephaly
Document Summary
Week 5: developmental neurogenesis and postnatal development (cont. ) Microcephaly: abnormally small brain caused by death of stem cells and/or insufficient proliferation. Can be caused by genetics - trisomy 21. Can be caused by environmental factors - fetal alcohol exposure, zika virus (specifically in pregnant woman) Cell migration: the movement of cells from one place to another. Starts around 8-9 weeks post-conception and is complete 2-3 months before birth. Radial: moving out from center (radiate outward) 2 main migration events in neural development: Tangential migration of neural crest cells to form schwann cells and neurons in peripheral nerves. Radial migration of cerebral cortical neurons to form the layers of the cerebral cortex - defects in radial migration of cortical neurons can cause lissencephaly, formation of a brain without fold and cortical layers. Differentiation: the process by which unspecialized stem cells or precursor cells take on their final specialized state.
