PSB-2000 Chapter 5: Chapter 5 Study Guide
Document Summary
Chapter 5 study guide- development and plasticity of brain. Similar among vertebrates, except for the number of cell divisions (higher in humans compared to chimpanzees). Migration: after cells have differentiated in neurons or glia they move. Different in speed- some reach targets until adulthood. Deficit: related to reduced brain size, impaired migration and others. Differentiation: process of forming dendrites and axons of neurons. Myelination: process by which glia produce the insulating fatty acid sheets that accelerates transmission in vertebrate axons. Cajal claims an adult vertebrate brain cannot generate new neurons (only until embryological or early infancy), however, there"re exception: A growing axon follows a path of cell-surface molecules, attracted by some chemicals and repelled by others, in a process that steers the axon in correct direction. Axons sort themselves over the surface of their targets area by following a gradient chemical. Axons make trial connections at first with many postsynaptic cells, then postsynaptic cells strengthens some synapses and eliminates others.
