Central melanocortins modulate mesocorticolimbic activity and food seeking behavior in the rat

Physiol Behav. 2011 Mar 28;102(5):491-5. doi: 10.1016/j.physbeh.2010.12.017. Epub 2010 Dec 21.


The hypothalamic melanocortin system is known for its role in regulating energy homeostasis through it actions within hypothalamic brain centers. However, emerging evidence suggests that this system regulates addictive behaviors through signaling within mesolimbic neurons. Here, we hypothesized the melanocortin system modulates feeding behavior through its actions on mesolimbic neurons. In particular, we predicted that central administration of the melanocortin antagonist agouti-related peptide (AgRP) would activate midbrain dopamine neurons, increase mesolimbic dopamine turnover, and alter food seeking behaviors. We found that intraventricular administration of agouti-related peptide increased neuronal activation within midbrain dopamine neurons in addition to increasing dopamine turnover in the medial prefrontal cortex. Additionally, using the conditioned place preference paradigm to assay food seeking behavior, we report that central injection of agouti-related peptide attenuates the acquisition of a conditioned place preference for sucrose, but not high fat diet. These results suggest that the melanocortin system is capable of regulating mesocorticolimbic activity and food seeking behavior.

MeSH terms

  • Agouti-Related Protein / administration & dosage
  • Agouti-Related Protein / pharmacology*
  • Animals
  • Conditioning, Psychological / drug effects
  • Dietary Fats / pharmacology
  • Dopamine / metabolism
  • Feeding Behavior / drug effects
  • Feeding Behavior / physiology*
  • Injections, Intraventricular
  • Melanocortins / drug effects
  • Melanocortins / physiology*
  • Neurons / metabolism
  • Neurons / physiology*
  • Nucleus Accumbens / drug effects
  • Nucleus Accumbens / metabolism*
  • Peptide Fragments / administration & dosage
  • Peptide Fragments / pharmacology*
  • Prefrontal Cortex / drug effects
  • Prefrontal Cortex / metabolism*
  • Rats
  • Rats, Long-Evans
  • Sucrose / pharmacology
  • Ventral Tegmental Area / drug effects
  • Ventral Tegmental Area / metabolism*


  • Agouti-Related Protein
  • Dietary Fats
  • Melanocortins
  • Peptide Fragments
  • agouti-related peptide, (Yc(CRFFNAFC)Y)
  • Sucrose
  • Dopamine