PRECLINICAL STUDY: FULL ARTICLE: Ghrelin increases intake of rewarding food in rodents

E Egecioglu, E Jerlhag, N Salomé… - Addiction …, 2010 - Wiley Online Library
E Egecioglu, E Jerlhag, N Salomé, KP Skibicka, D Haage, M Bohlooly‐Y, D Andersson…
Addiction biology, 2010Wiley Online Library
We investigated whether ghrelin action at the level of the ventral tegmental area (VTA), a key
node in the mesolimbic reward system, is important for the rewarding and motivational
aspects of the consumption of rewarding/palatable food. Mice with a disrupted gene
encoding the ghrelin receptor (GHS‐R1A) and rats treated peripherally with a GHS‐R1A
antagonist both show suppressed intake of rewarding food in a free choice (chow/rewarding
food) paradigm. Moreover, accumbal dopamine release induced by rewarding food was …
Abstract
We investigated whether ghrelin action at the level of the ventral tegmental area (VTA), a key node in the mesolimbic reward system, is important for the rewarding and motivational aspects of the consumption of rewarding/palatable food. Mice with a disrupted gene encoding the ghrelin receptor (GHS‐R1A) and rats treated peripherally with a GHS‐R1A antagonist both show suppressed intake of rewarding food in a free choice (chow/rewarding food) paradigm. Moreover, accumbal dopamine release induced by rewarding food was absent in GHS‐R1A knockout mice. Acute bilateral intra‐VTA administration of ghrelin increased 1‐hour consumption of rewarding food but not standard chow. In comparison with sham rats, VTA‐lesioned rats had normal intracerebroventricular ghrelin‐induced chow intake, although both intake of and time spent exploring rewarding food was decreased. Finally, the ability of rewarding food to condition a place preference was suppressed by the GHS‐R1A antagonist in rats. Our data support the hypothesis that central ghrelin signaling at the level of the VTA is important for the incentive value of rewarding food.
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