title: [NADPH-diaphorase, nitric oxide synthase, and tyrosine hydroxylase in the diencephalon of the Rhodeus sericeus (Cyprynidae:Teleostei)].
abstract: The presence and distribution of nitric oxide synthase (NOS)-like neurons as well as tyrosine hydroxylase-immunoreactive (TH) neurons was studied in the diencephalon of the cypriniform teleost Rhodeus sericeus. The anatomical relationships between tyrosine hydroxylase (TH)- and nitric oxide synthase (NOS)-containing cells were visualized both by NOS-immunohistochemistry and NADPH-histochemistry. Immunohistochemical labeling and morphological studies were performed on the same sections. The results reported in this paper show that both a NOS and TH activity are present in the preoptic region, posterior tuberculum, paraventricular organ and hypothalamus of R. sericeus. Putative nitrergic neurons were identified in all major hypophysiotrophic nuclei of the R. sericeus brain using both NADPH-d histochemistry and nNOS immunohistochemistry. In the preoptic region, nitrergic neurons were found in both the parvocellular and the magnocellular nuclei. Within these nuclei, the distribution of NADPH-d reactivity was similar to that of nNOS immunoreactivity. However, we found no evidence of colocalization of NADPH-d and nNOS in consecutive sections. NOS- and TH-containing neurons were observed in all the nuclei under study (hypothalamus, posterior tuberculum, ventral thalamus) and telencephalon (preoptic region), although most neurons showing the coexistence of both substances were mainly located in the preoptic nucleus and hypothalamus, some labelled neurons were found in the posterior tuberculum. Most of the cerebrospinalliquor-contacting cells (LCNs) in diencephalic periventricular area of R. sericeus were TH-immunoreactive. Also, a large number ofnitrergic small LCNs distributed throughout the third ventricle were observed in these regions. The data obtained supports the existence of a nitrergic circumventricular system in teleost. LCNs in R. sericeus are thought to be involved in osmoregulatory functions as osmosensitive neurons. Due to their chemical properties, NO produced by these cells might play an important role in the maintenance and regulation of CSF homeostasis through the modulation of cerebral blood flow.
authors.forename: E V
authors.initials: EV
authors.lastname: Pushchina
authors.forename: D K
authors.initials: DK
authors.lastname: Obukhov
mesh_terms: D000818:Animals; D003530:Cyprinidae / Q000033:anatomy & histology / Q000378:metabolism*; D004027:Diencephalon / Q000033:anatomy & histology / Q000201:enzymology*; D007150:Immunohistochemistry; D009252:NADPH Dehydrogenase / Q000032:analysis / Q000378:metabolism*; D019001:Nitric Oxide Synthase / Q000032:analysis / Q000378:metabolism*; D014446:Tyrosine 3-Monooxygenase / Q000032:analysis / Q000378:metabolism*
chemical_list: D019001:Nitric Oxide Synthase; D014446:Tyrosine 3-Monooxygenase; D009252:NADPH Dehydrogenase