Increased vascularity and alterations in cytochrome oxidase distribution associated with abnormal hippocampal cytoarchitecture in micrencephalic rats.

Prenatal exposure of the developing rat brain to methylazoxymethanol acetate results in the formation of ectopic groups of pyramidal neurons in the subfields CA1 and CA2 of the mature hippocampal formation. These ectopic neurons are situated in regions of increased vascularization and increased activity of cytochrome oxidase, as demonstrated histochemically. Both these findings suggest that there may be an abnormality of distribution or intensity of oxidative metabolic activity in the ectopic pyramidal neurons found in these animals.