Cellular and Molecular Neurobiology
Author: Julieta Aguggia | email: juliaguggia@gmail.com
Julieta Aguggia 1°, Gimena Fernandez 1°, Daniela Cassano 1°, Paula Cornejo 1°, Franco Barrile 1°, Camila Saenz 1°, Abdella Habib 2°, Mario Perelló 1°
1° Grupo de Neurofisiología, Instituto Multidisciplinario de Biología Celular (IMBICE). Universidad Nacional La Plata (UNLP), Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET) y Comisión de Investigaciones Científicas de la Provincia de Buenos Aires (CIC-PBA). La Plata, Argentina.
2° College of Medicine, QU Health, Qatar University, Doha, Qatar.
Ghrelin is a stomach-derived orexigenic hormone that acts via the growth hormone secretagogue receptor (GHSR), highly expressed in the brain that increases food intake and glycemia. The Glucagon-like peptide-1 (GLP-1) is a hormone released by the gastrointestinal tract in response to meal intake that acts via the GLP-1 receptor (GLP-1R) and reduces food intake and glycemia. Interestingly, GHSR and GLP-1R expression have been observed within many of the same nuclei of the brain, suggesting may act on common neuronal sets to mediate its neurobiological effects. Here, we explored the extent of this putative direct GHSR and GLP-1R interaction in the brain. We mapped the distribution of the GHSR in the mouse brain and examined the localization of this receptor using two complementary approaches: binding with fluorescent-labeled ghrelin (Fr-ghrelin) in wild type mice or visualizing the endogenous fluorescence of GHSR-eGFP mice in which eGFP is under the control of the GHSR promoter. In both cases, the presence of GLP-1R was visualized by immunohistochemistry using a validated anti-GLP1R antibody. We found that cells containing both GHSR and GLP-1R are mainly located in the hippocampus dentate gyrus. In contrast, simultaneous presence of GHSR and GLP-1R was much less extensive elsewhere in the brain.Thus, we conclude that GHSR and GLP-1R signaling may directly crosstalk in the hippocampus whereas they act largely on distinct neuronal populations in other parts of the mouse brain.