Complex experience promotes capillary formation in young rat visual cortex.

The metabolic support of neural plasticity was examined by comparing cerebral vasculature of weanling rats reared in complex environments (EC) to littermates reared individually (IC) or socially in pairs (SC). EC rats have a thicker occipital cortex, more synaptic contacts per neuron and larger dendritic arbors compared to SC or IC rats, potentially increasing local metabolic demands on microvasculature. Capillaries of EC rats were closer together than those of SC or IC rats and potentially filled a greater fraction of cortex with blood. The closer capillary spacing in young EC rats suggests compensatory angiogenesis in response to increased metabolic demand.