NITRIC-OXIDE SYNTHASE-EXPRESSING NEURONS ARE AREA-SPECIFICALLY DISTRIBUTED WITHIN THE CEREBRAL-CORTEX OF THE RAT

Neuronal nitric oxide synthase produces nitric oxide, a radical involv ed in neurotransmission as well as in cytotoxicity during stroke and n eurodegenerative diseases. In the adult Wistar rat neuronal nitric oxi de synthase-positive neurons are inhomogenously distributed along defi ned cortical areas, with highest densities (18 cells/mm(2)) in cingula r area 1, piriform cortex, frontal motor area Fr 2 and in the medial v isual association area Oc 2MM. A medium packing density of neuronal ni tric oxide synthase neurons (10/mm(2)) characterizes primary sensory a reas, whereas retrosplenial cortices contain lowest cell numbers (3-5/ mm(2)). The data suggest that functions of certain cortical areas are more dependent on intracortically produced nitric oxide than others, a nd that cortical injury may cause more severe nitric oxide-related cyt otoxicity in areas with higher numbers of neuronal nitric oxide syntha se-positive neurons. (C) 1997 IBRO. Published by Elsevier Science Ltd.