Orexin and neuropeptide Y: Tissue specific expression andimmunoreactivity in the hypothalamus and preoptic area of thecichlid fish Cichlasoma dimerus

PÉREZ SIRKIN, DANIELA; SUZUKI,H; CÁNEPA, MAXIMILIANO; VISSIO, PAULA

TISSUE & CELL

CHURCHILL LIVINGSTONE

Lugar: ESCOCIA; Año: 2013 vol. 45 p. 452 - 459

0040-8166

Neuropeptide Y (NPY) and orexin are neuropeptides involved in the regulation of feeding in vertebrates.In this study we determined the NPY and orexin mRNA tissue expression and their immunoreactivity dis-tribution in both preoptic area and hypothalamus, regions involved in the regulation of feeding behavior.Both peptides presented a wide expression in all tissues examined. The NPY-immunoreactive (ir) cellswere localized in the ventral nucleus posterioris periventricularis (NPPv) and numerous ir-NPY fibers werefound in the nucleus lateralis tuberis (NLT), the nucleus recess lateralis (NRL) and the neurohypophysis.Ir-orexin cells were observed in the NPPv, dorsal NLT, ventral NLT, lateral NLT (NLTl) and the lateral NRL.Ir-orexin fibers were widespread distributed along all the hypothalamus, especially in the NLTl. Addi-tionally, we observed the presence of ir-orexin immunostaining in adenohypophyseal cells, especiallyin somatotroph cells and the presence of a few ir-orexin-A fibers in the neurohypophysis. In conclusion,both peptides have an ubiquitous mRNA tissue expression and are similarly distributed in the hypothal-amus and preoptic area of Cichlasoma dimerus. The presence of ir-orexin in adenohypohyseal cells andthe presence of ir-orexin and NPY fibers in the neurohypophysis suggest that both peptides may play animportant neuroendocrine role in anterior pituitary.