Ghrelin Signaling Diferentially Activates Non-Dopaminergic Neurons of the Ventral Tegmental Area Subregions

CORNEJO, MARÍA PAULA; BARRILE, FRANCO; DE FRANCESCO, PABLO NICOLÁS; PERELLO, MARIO

Mar Del Plata

Congreso; XXXII Congreso de la Sociedad Argentina de Investigación en Neurociencias (SAN); 2017

Sociedad Argentina de Investigación en Neurociencias (SAN)

The ventral tegmental area (VTA)together with the nucleus accumbens (Acb) form the mesolimbic pathway, which isinvolved in the regulation and processing of the rewarding aspects of foodconsumption. The VTA comprises different neuronal populations, includingdopaminergic, GABAergic and glutamatergic neurons. The VTA and Acb are bothdivided in three different sub-divisions with differential connectivity.Ghrelin is a peptidic orexigenic hormone secreted from stomach that binds to aG-protein coupled receptor, the growth hormone secretagogue receptor (GHSR).GHSR is expressed in several brain nuclei involved in food intake regulation,including the VTA. In this study, we investigated the ability of ghrelin toreach and activate VTA and Acb sub-divisions. We found that peripherallyadministered ghrelin fails to reach and increase the levels of the marker ofneuronal activation c-Fos in both the VTA and the Acb. We also found thatcentrally administered ghrelin reaches VTA neurons and increases c-Fos indifferent sub-divisions of the VTA and Acb. Finally, we show that dopaminergicneurons of the VTA fail to increase c-Fos in response to centrally administeredghrelin. Thereby, we conclude that central ghrelin is able to reach the VTA andto activate VTA and Acb sub-divisions, and that VTA neurons activated byghrelin are not dopaminergic neurons.