Study of the interaction between ghrelin- and high fat diet-induced acute food intake in mice

SPRING VALDIVIA; AGUSTINA CABRAL; ANABELA PATRONE; MIRTA REYNALDO; MARIO PERELLO

Congreso; XXVI Congreso Anual de la Sociedad Argentina de Investigación en Neurociencia; 2011

Ghrelin is a stomach-derived hormone that acts on homeostatic and hedonic brain centers to increase food intake. We have shown that ghrelin administration affects the rewarding value of high fat diet. However, it is currently unclear how the neural circuits activated by either ghrelin or high fat diet (HFD) interact to modulate eating. Here, we quantified acute food intake in wild type mice injected with ghrelin and exposed to either HFD alone, regular chow alone or a combination of both diets. Also, we performed immunohistochemistry for cfos in the mouse brains to map the neuronal circuits activated in each experimental condition. We found that i-ghrelin increases food intake of regular chow; ii-HFD alone strongly activates food intake; and ii-ghrelin fails to further affect HFD intake or short-term HFD preference. Also, we found i-ghrelin increases cfos expression mainly in hypothalamic nuclei; ii-HFD intake increases cfos mainly in centers of the mesolimbic pathway; and iii-the combination of HFD ingestion and ghrelin administration increase cfos expression in both hypothalamic and mesolimbic pathways. Thus, we conclude that HFD potently induces food intake due to the activation of hedonic centers, which override the acute effects of ghrelin on eating.