ULTRASTRUCTURAL-LOCALIZATION OF NITRIC-OXIDE SYNTHASE IMMUNOREACTIVITY IN THE FRONTAL-CORTEX OF THE MONKEY

By use of electron microscopic immunocytochemistry with an antiserum a gainst nitric oxide synthase (NOS), we demonstrated that, in the front al cortex (area 45) of the monkey, NOS was localized both within some axon terminals which synapsed on NOS-negative dendrites and within som e dendrites which formed synapses with NOS-negative axon terminals. Th is finding suggests that nitric oxide can be produced in and released from both pre- and postsynaptic neuronal elements in the monkey cerebr al cortex.