Diversity in localisation of nitric oxide synthase antigen and NADPH-diaphorase histochemical staining in sacral somatic motor neurones of the cat.

Nitric oxide synthase (NOS) immunoreactivity occurred in about 60% of ventromedial, ventrolateral, and sphincteric motoneurones in cat sacral spinal cord. Proportions of sacral motoneurones histochemically stained for NADPH-diaphorase, were similar, and equivalent in size to those immunoreactive for NOS, suggesting co-localisation of diaphorase and NOS. Double staining techniques revealed that NOS co-localised with NADPH-diaphorase in approximately 60% of sacral motoneurones. Some remaining motoneurones exhibited neither NOS nor NADPH-diaphorase, while others exhibited only NOS or NADPH-diaphorase, indicating phenotypic differences among sacral motoneurones.