Abstract | RATIONALE: The melanocortin system is an important component of the brain circuitry controlling feeding and body weight, and most of the effects of melanocortins are attributed to their actions in hypothalamic and brainstem nuclei. The mesolimbic dopamine system is another component of the central circuitry controlling feeding, and there is evidence that melanocortins can act on mesolimbic dopamine pathways. It is unknown, however, whether melanocortins can act on the mesolimbic dopamine system to regulate feeding. OBJECTIVE: These studies tested whether injection of melanocortin receptor agonists and antagonists directly into the ventral tegmental area (VTA) of adult rats affects feeding and body weight. METHODS: RESULTS: Injection of MTII into the VTA dose-dependently inhibited feeding for up to 24 h, while injection of SHU9119 into the VTA dose-dependently stimulated feeding for up to 24 h. In addition, chronic blockade of melanocortin receptors in the VTA increased feeding, body weight, and caloric efficiency. CONCLUSIONS: These studies demonstrate that melanocortins can control feeding and body weight by acting in the VTA and suggest that endogenous melanocortins control feeding in part through actions on the mesolimbic dopamine system in vivo.
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Authors | Aaron G Roseberry |
Journal | Psychopharmacology
(Psychopharmacology (Berl))
Vol. 226
Issue 1
Pg. 25-34
(Mar 2013)
ISSN: 1432-2072 [Electronic] Germany |
PMID | 23010797
(Publication Type: Journal Article)
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Chemical References |
- Melanocortins
- Receptors, Melanocortin
- alpha-MSH (4-10)amide, Ac-Nle(4)-cyclo(Asp(5)-Phe(7)-Lys(10))-
- SHU 9119
- alpha-MSH
- Melanocyte-Stimulating Hormones
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Topics |
- Animals
- Body Weight
(drug effects)
- Brain Mapping
- Dose-Response Relationship, Drug
- Feeding Behavior
(drug effects)
- Male
- Melanocortins
(metabolism)
- Melanocyte-Stimulating Hormones
(administration & dosage, pharmacology)
- Microinjections
- Rats
- Rats, Sprague-Dawley
- Receptors, Melanocortin
(agonists, antagonists & inhibitors)
- Time Factors
- Ventral Tegmental Area
(drug effects, metabolism)
- alpha-MSH
(administration & dosage, analogs & derivatives, pharmacology)
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