Ghrelin increases intake of rewarding food in rodents

Addict Biol. 2010 Jul;15(3):304-11. doi: 10.1111/j.1369-1600.2010.00216.x. Epub 2010 May 6.

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.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Conditioning, Classical / drug effects
  • Dopamine / metabolism
  • Eating / drug effects*
  • Ghrelin / pharmacology*
  • Injections
  • Limbic System / drug effects*
  • Male
  • Mesencephalon / drug effects*
  • Mice
  • Mice, Knockout
  • Neural Pathways / drug effects*
  • Nucleus Accumbens / drug effects
  • Receptors, Ghrelin / drug effects
  • Receptors, Ghrelin / genetics
  • Reward*
  • Signal Transduction / drug effects
  • Taste / drug effects
  • Ventral Tegmental Area / drug effects*

Substances

  • Ghrelin
  • Receptors, Ghrelin
  • Dopamine