HLTH 210 Lecture Notes - Lecture 9: Synaptic Pruning, Prefrontal Cortex, Frontal Lobe
23 Mar 2017
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Document Summary
Brain grows during life, but the growth is not due to an increase in the number of neurons. Growth of grey matter volume due to increased glial cells, increase in synaptic density etc. Growth of white matter due to myelination of axons. Synaptogenesis is the process where new synapses are formed. During the 1st year of life, up to 1000 new synapses per second. Occurs in different regions of the brain at different times. Spines are small protrusions off dendrites where synapses actually occur. Not just the tips of dendrites forming synapses, but all along the dendrites via spines. Pruning is the process of eliminating unnecessary/unused connection. About 50% of all synapses formed during infancy are eliminated in the adult. Myelination occurs at the same time as pruning. If adverts stimulus is removed before age 2, the child can catch up and develop normally. If removed after 2 or not at all, adverse effects on development.
