ScienceDaily (Oct. 19, 2006) — The need to eat is initiated, in part, by a hormone known as ghrelin. Although ghrelin is known to be produced in the gut and to trigger the brain to promote eating, it remains to be determined precisely how ghrelin affects different parts of the brain.

Now, in a study appearing online on October 19, in advance of publication in the December print issue of the Journal of Clinical Investigation, researchers from Yale University, have shown that in mice and rats ghrelin triggers the same neurons as delicious food, sexual experience, and many recreational drugs; that is, neurons that provide the sensation of pleasure and the expectation of reward.

These neurons produce dopamine and are located in a region of the brain known as the ventral tegmental area (VTA). Tamas Horvath and colleagues showed that ghrelin bound its receptor on neurons of the VTA and triggered their production of dopamine. Importantly, infusion of ghrelin into the VTA of rats increased their food intake. Conversely, infusion of inhibitors of the ghrelin receptor into the VTA of rats decreased the amount they consumed after a 24-hour fast.

This study identifies the VTA as a site of action for ghrelin to induce food intake. As this region of the brain is also triggered by many recreational drugs and is known to be produce the expectation of reward, the authors suggest that ghrelin stimulation of the VTA might be involved in diseases of food abuse.

Recommend this story on Facebook, Twitter,
and Google +1:

Other bookmarking and sharing tools:

Story Source:

The above story is reprinted from materials provided by Journal of Clinical Investigation, via EurekAlert!, a service of AAAS.

Note: Materials may be edited for content and length. For further information, please contact the source cited above.

Disclaimer: This article is not intended to provide medical advice, diagnosis or treatment. Views expressed here do not necessarily reflect those of ScienceDaily or its staff.

Related Stories

Search ScienceDaily