PSYB65H3 Chapter Notes - Chapter 13: Marasmus, Teratology, Cerebral Atrophy
Document Summary
50% more neurons are produced in the developing brain than are required in the adult brain: neural death is apoptotic, or planned, programmed cell death. Plastic change is the ability of the cns to alter itself in response to environmental stimuli: critical periods of plastic change in which the environment can have a maximal effect on the cns. Duration and timing of this vary by species. Longer-lived animals (eg. humans) exhibit prolonged critical periods that often occur later in life. Experience-expectant plastic changes those cns changes that are dependent on experience(s) during the critical period for specific synapses to develop as they should: much of the sensory cortex appears to have these. If an organism does not experience sensory stimulation during the critical period, long- lasting impairments in the sensory modality occur. Plastic change required for learning extend well into adulthood: neurotrophins play critical roles.
