Laminar variation in the microvascular architecture of normal human visual cortex (area 17).

Diameters and densities of arterioles and capillaries were measured in thick alkaline phosphatase-stained sections of human visual cortex from normal young adults. Values were compared between laminae. Capillary diameters ranked: IV greater than V-VI greater than II-III greater than I; capillary densities ranked: IV greater than II-III greater than V-VI greater than I. The striking capillary density of lamina IV overlaps the stria Gennarii and, like it, is limited to area 17. The data suggest correlations with similar laminar distributions of some neurotransmitters and of certain common neuropathological lesions.