PSY312H1 Lecture : Cognitive development 10 Nov 16.docx
Document Summary
Push for neurogenesis is first 20 weeks of gestation, but seems to somewhat stop at birth- Although new neurons are created in adults but only in specific parts of the brain (hippocampus for spatial functioning, memory, dentate gyrus?) Takes few weeks for neurogenesis to get started (eg. takes few weeks for depression meds to work) Neurons reach their final destination about 7 months after conception. Nodes of ranvier- periodic breaks in mylenation, can jump from one link to next shortens. Infants born with more neurons than they need, apoptosis to prune away what doesn"t get used. Neurons not close to other neurons that are active don"t get bdnf. Neurons that are not getting bdnf (factors) are not important, so they should be pruned. Pruning frees up homeostatic/meta resources in the brain. High iq kids show early pruning and early neurogenesis.
