Requirement of central ghrelin signaling for alcohol reward.

Hungry for an alcoholic drink? This intriguing paper suggests that the hormone ghrelin facilitates in mice the motivation to drink alcohol (in addition to its well-known role in strengthening the motivation to eat food).

Ghrelin is a hormone typically released from the stomach into the bloodstream at the beginning of meals that is known to promote appetite and food intake. Here, Jerlhag and colleagues report that it may also promote alcohol intake. They show that microinjections of ghrelin into the ventral tegmentum or into cerebral ventricles increased behavioral consumption of alcohol. By contrast, microinjections or systemic administration of receptor-blocking antagonists reduced alcohol consumption. This may reflect more than an appetite for calories, because the authors report that mutant knockout mice lacking GHS-R1A ghrelin receptors further showed deficits in alcohol-induced conditioned place preference, and related stimulation of dopamine release in the nucleus accumbens. All in all, these results seem to suggest a role for the effects of ghrelin on the brain in the motivation for alcohol consumption.