Ghrelin Action in the Ventral Tegmental Area Increases Locomotor Activity Independently of Food Intake Regulation

BARRILE, FRANCO; CORNEJO, MARÍA PAULA; 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)

Ghrelin is a stomach-derivedoctanoylated peptide hormone that regulates a variety of central functions viaits action on a specific ghrelin receptor that is highly expressed in thebrain. Here, we investigated if ghrelin´s effects on food intake and locomotoractivity in mice involve the action of the hormone on the ventral tegmentalarea (VTA), a midbrain area known to regulate both functions and expressghrelin receptor. We found that: 1) subcutaneously-injected ghrelin increasesboth food intake and the level of the marker of neuronal activation cFos in thehypothalamic arcuate nucleus (ARC) while it fails to increase cFos levels inthe VTA. In addition, subcutaneously injected ghrelin fails to affect locomotoractivity in mice without access to food; 2) centrally-injected ghrelinincreases food intake as well as cFos levels in the ARC and the VTA. Inaddition, centrally-injected ghrelin increases locomotor activity in micewithout access to food; 3) intra-VTA injected ghrelin fails to affect foodintake and cFos levels in the ARC while it increases locomotor activity as wellas the cFos levels in the VTA. Thus, our results show that ghrelin action atthe ARC increases food intake without effects on the locomotor activity whileghrelin action at the VTA increases locomotor activity without effects on thefood intake. We conclude that the ghrelin effects on food intake and locomotoractivity are neuroanatomically dissociated.