DIHYDRONICOTINAMIDE ADENINE-DINUCLEOTIDE DIAPHORASE IN THE CENTRAL-NERVOUS-SYSTEM OF THE CRESTED NEWT

By using a histochemical procedure, the distribution of neurons contai ning dihydronicotinamide adenine dinucleotide diaphorase (NADPHd) was examined in the brain, retina and olfactory epithelium of the urodele amphibian Triturus carnifex. Positive nerve fibers and terminals were observed throughout the brain and cell bodies were seen within the tel encephalon, optic tectum, brain stem, cerebellum and spinal cord. In t he retina, NADPHd labeling was localized in the outer segment of photo receptors and in some amacrine cells as well as in the outer and inner plexiform layers. In the olfactory epithelium, NADPHd labeling was fo und in the olfactory neurons. By comparing NADPHd distribution with ni tric oxide synthase (NOS) immunoreactivity (using a polyclonal antiser um raised against mouse cerebellar NOS) it was found that NADPHd label ing and NOS immunoreaction patterns generally matched. The organizatio n of NADPHd and NOS containing neurons in the central nervous system o f the crested newt, which is simpler than in other vertebrates investi gated, shows some peculiarities, such as the occurrence of NADPHd in t he pinealocytes of the epiphysis, nucleus ruber of the brain stem and eminentia cerebellar is ventralis of the cerebellum.