Neuroendocrinology and Neuroimmunology
Author: Daniela Alejandra Cassano | email: danicassano@hotmail.com
Daniela Alejandra Cassano 1°, Franco Barrile 2°, Mirta Reynaldo 3°, García Romero Guadalupe 2°, Mario Perelló 2°
1° AGENCIA (MINCyT)
2° CONICET
3° CIC
Ghrelin is a stomach-derived hormone that acts via growth hormone secretagogue receptor (GHSR). Plasma ghrelin levels and consummatory behaviours towards rewarding stimuli increase in calorie restricted (CR) animals. Since ghrelin is known to regulate reward-related behaviours, we tested here if GHSR signalling mediates the enhancement of consummatory behaviours in CR mice and its putative neurobiological basis. Using a CR protocol, in which mice were daily exposed to a saccharine solution for 4h before food intake, we found that CR GHSR-deficient mice consumed less saccharine and showed smaller induction of cFos in key centers of the mesolimbic pathway, such as the lateral hypothalamic area (LHA) and the nucleus accumbens (Acb), than WT mice indicating that GHSR is required to enhance rewarding consummatory behaviours in CR mice. Using mice with ablation of the arcuate nucleus (ARC), we found that the ARC is not required for the increase of saccharine consumption or cFos activation in the LHA and Acb observed in CR mice. Also, we found that CR mice with GHSR expression in dopamine neurons showed saccharine consumption as seen in CR GHSR-def mice indicating that GHSR only in dopamine neurons is not sufficient to enhance consummatory behaviors in CR. Also, CR mice with GHSR expression exclusively in the LHA showed increased saccharine intake, as compared to GHSR-def mice. Thus, we conclude that GHSR in the LHA could mediate the enhancement of consummatory behaviors under CR.