DISTRIBUTION OF NITRIC-OXIDE SYNTHASE IN THE CENTRAL-NERVOUS-SYSTEM OF MACACA-FUSCATA - SUBCORTICAL REGIONS

The distribution of nitric oxide synthase-immunoreactive neurons was s tudied in the Macaca fuscata by immunohistochemistry using antiserum a gainst nitric oxide synthase. In the macaque lower brainstem, many nit ric oxide synthase-containing cell bodies were found in the gigantocel lular and parvocellular reticular nuclei, the nucleus of the spinal tr act of trigeminal nerve, the cochlear nucleus, the prepositus hypoglos si and the nucleus of the solitary tract. Many nitric oxide synthase-i mmunoreactive perikarya were observed in the laterodorsal-pedunculopon tine tegmental nucleus complex of the macaque pontine and midbrain teg mentum. In addition, there were many highly immunoreactive cell bodies in the superficial layers of the inferior and superior colliculi. In the forebrain, numerous cell bodies were observed in the caudate nucle us, putamen, nucleus accumbens, nucleus of the diagonal band, anterior perforated substance and amygdaloid complex. Whereas most of these ne urons were labeled highly intense for nitric oxide synthase, there wer e also many lightly labeled nitric oxide synthase-immunoreactive neuro ns in the substantia innominata, globus pallidus, ansa peduncularis an d lateral hypothalamic nucleus. The present observation indicated some species difference in the distribution of central nitric oxide syntha se-containing neurons. Furthermore, the present neuroanatomical eviden ce that nitric oxide synthase is distributed in a variety of specific neuronal systems, with some differences in the patterns of cytoplasmic localization, further indicates the neural messenger role of nitric o xide in the central nervous system.