Brain distribution of immunoreactive neurons and fibers expressing GnIH in pejerrey, Odontesthes bonariensis.

PAHI-ROSERO, A.M; PÉREZ, MA. RITA; LÓPEZ, G.C.; VISSIO, P.G.; SOMOZA, GUSTAVO M

CABA

Congreso; REUNIÓN CONJUNTA DE SOCIEDADES DE BIOCIENCIAS; 2017

Sociedad Argentina de Biología

BRAIN DISTRIBUTION OF IMMUNOREACTIVE NEURONS AND FIBERS EXPRESSING GnIH IN PEJERREY, Odontesthes bonariensis.Ana María Pahí-Rosero (1), María Rita Pérez (1), Gabriela Carina López (1), Paula Gabriela Vissio (2), Gustavo Manuel Somoza (1)(1) IIB-INTECH (CONICET-UNSAM). (2) DBBE (FCEyN,UBA).Gonadotrophin-inhibitory hormone (GnIH) is a RFamide peptide, originally characterized in the japanese quail as an inhibitor of gonadotropins, changing the classical view of the regulation of vertebrate reproduction. Later, it was also found in others vertebrate species, with similar function. However, the effects in fish remain controversial. In this context, as a first step, the objective of this work was characterized the neuroanatomic distribution of GnIH neurons and fibers in the brain of adult pejerrey by immunohistochemistry. Our results showed that neuronal somata with immunoreactivity to GnIH (ir-GnIH) were localized at the olfactory bulbs, the junction of the olfactory bulbs and telencephalon (Terminal Nerve Ganglion or Nucleus Olfacto Retinalis) and the Nucleus Posterioris Periventricularis (NPPv). This distribution was similar to that reported in other teleost fish species. Moreover, some isolated neuronal somata were detected in the Nucleus Paraventricularis Posterioris (NPP) in the preoptic area (POA). While ir-GnIH fibres were present in all brain areas examined, and also at the pituitary gland. In addition, double labelling with GnIH and GnRH I (also known as pjGnRH) antisera was performed, in order to analyze a possible relationship between GnIH and the hypophysiotropic GnRH variant of this species. In double labelling immunocytochemistry, ir-GnIH fibers were localized very close to ir-GnRH neurons in the preoptic area, suggesting that both neurons could interact. This is the report on the GnIH distribution in the brain of pejerrey and its relation with GnRH.