Development of the Cerebral Cortex

• Synapse elimination (pruning) occurs late in childhood and in adolescence;

• it is followed by a much slower decline in synaptic density during the adult years;

• depending on cortical region, max. synaptic density at 1.4 to 4.4 yrs. of age;

• adult synaptic density= 60% of the max.;

• pruning is necessarily associated with reductions in total cortical gray matter, and reflected in both laminar and total cortical thickness;