Bilateral induction of NADPH-diaphorase activity in neocortical and hippocampal neurons by unilateral injury.

Unilateral injury of the cerebral cortex or hippocampus induced a bilateral appearance of NADPH-diaphorase in some pyramidal neuronal and glial cells of both structures. Only in the cerebral cortex, near the needle track, did some V layer pyramidal neurons contain so much of this enzyme that they looked to be stained by the Golgi method. The induction of NADPH-diaphorase in a subset of cortical and hippocampal neurons in both hemispheres after unilateral injections of either cysteamine or artificial cerebro-spinal fluid suggests the existence in the isocortex and the hippocampus of a selective signalling system which may play a role in recovery of function following local brain damage.