CONICET | Buscador de Institutos y Recursos Humanos

Gonadotropin inhibitory hormone (Gnih) is a neuropeptide that inhibits the reproductive axis in birds and mammals. In recent years, Gnih has also been shown to be involved in the regulation of feedingand the control of energy homeostasis in these groups. In teleost fishes, a growing number of studies demonstrate that Gnih regulates reproductive function; however, there are few studies linking Gnih to feeding and nutritional status in this group. In our laboratory, preliminary results showed that four weeks of fasting conditions induced a significant decrease in Gnih mRNA levels in the hypothalamus of the cichlid fish Cichlasoma dimerus. Taking into account our results, we proposed that Gnih could act as a link between feeding and reproduction. Therefore, this work aimed to study the anatomical relationships between Gnih producing neurons and those thatproduced the main hypothalamic hormones involved in feeding control, proopiomelanocortin (Pomc), and neuropeptide Y (Npy) in C. dimerus. Adults were sampled, and the brains were dissected and processed for double-immunofluorescence. By double immunofluorescence, we found a close association between Npy-immunoreactive (-ir) somata and Gnih-ir fibers in the nucleus posterior periventricularis of the hypothalamus, as well as fiber-fiber closeassociations along the ventral hypothalamus. With respect to Pomcir neurons, we observed fiber-somatic and fiber-fiber contacts with Gnih-ir fibers in the nucleus lateralis tuberis as well as fiber-fiber contacts in the preoptic area. We also found that Npy-ir fibers are in close contact with Pomc-ir somata and its fibers. No differences were observed between males and females. In conclusion, to our knowledge, this is the first study performed in a teleost fish to show a morphological association between Gnih, Pomc, and Npy, providing evidence that this neuroendocrine network may be conserved along the vertebrate lineage.

enviar mensaje