Ghrelin action in the ventral tegmental area increases locomotor activity independently of food intake regulation

BARRILE F; CORNEJO MP; DE FRANCESCO PN; PERELLO M

Mar Del Plata

Congreso; XXXII Reunión Anual de la Sociedad Argentina de Neurociencias; 2017

Sociedad Argentina de Investigación en Neurociencias

Ghrelin is a stomach-derived octanoylated peptide hormone that regulates a variety of central functions via its action on a specific ghrelin receptor that is highly expressed in the brain. Here, we investigated if ghrelin´s effects on food intake and locomotor activity in mice involve the action of the hormone on the ventral tegmental area (VTA), a midbrain area known to regulate both functions and express ghrelin receptor. We found that:1) subcutaneously-injected ghrelin increases both food intake and the level of the marker of neuronal activation cFos in the hypothalamic arcuate nucleus (ARC) while it fails to increase cFos levels in the VTA. In addition, subcutaneously injected ghrelin fails to affect locomotor activity in mice without access to food;2) centrally-injected ghrelin increases food intake as well as cFos levels in the ARC and the VTA. In addition, centrally-injected ghrelin increases locomotor activity in mice without access to food;3) intra-VTA injected ghrelin fails to affect food intake and cFos levels in the ARC while it increases locomotor activity as well as the cFos levels in the VTA. Thus, our results show that ghrelin action at the ARC increases food intake without effects on the locomotor activity while ghrelin action at the VTA increases locomotor activity without effects on the food intake. We conclude that the ghrelin effects on food intake and locomotor activity are neuroanatomically dissociated.