Abstract
CART (cocaine- and amphetamine-regulated transcript) peptides are neuromodulators that are involved in feeding, drug reward, stress, cardiovascular function, and bone remodeling. CART peptides are abundant but discretely distributed in the brain, pituitary and adrenal glands, pancreas, and gut. High expression of CART in discrete hypothalamic nuclei associated with feeding has led to behavioral and pharmacological studies that strongly support an anorectic action of CART in feeding. Subsequent studies on humans and transgenic animals provide additional evidence that CART is important in the regulation of appetite as mutations in the CART gene are linked to eating disorders, including obesity and anorexia. The expression of CART in the mesolimbic dopamine circuit has lead to functional studies demonstrating CART's psychostimulant-like effects on locomotor activity and conditioned place preference in rats. These and other findings demonstrated that CART modulates mesolimbic dopamine systems and affects psychostimulant-induced reward and reinforcing behaviors. The link between CART and psychostimulants was substantiated by demonstrating alterations of the CART system in human cocaine addicts. CART seems to regulate the mesolimbic dopamine system, which serves as a common mechanism of action for both feeding and addiction. Indeed, recent studies that demonstrated CART projections from specific hypothalamic areas associated with feeding to specific mesolimbic areas linked to reward/motivation behaviors provide evidence that CART may be an important connection between food- and drug-related rewards. Given the enormous public health burden of both obesity and drug addiction, future studies exploring the pharmacotherapies targeting CART peptide represent an exciting and challenging research area.
Footnotes
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This work was supported by National Institutes of Health Grants RR00165, DA00418, DA10732, HD37583, and DA15513.
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A.V. and D.C.J. contributed equally to this work.
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Article, publication date, and citation information can be found at http://jpet.aspetjournals.org.
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doi:10.1124/jpet.105.091512.
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ABBREVIATIONS: CART, cocaine- and amphetamine-regulated transcript; VMN, ventromedial hypothalamic nucleus; LH, lateral hypothalamus; Arc, arcuate nucleus; PVN, paraventricular nucleus; NTS, the nucleus of the solitary tract; CRF, corticotrophin-releasing factor; DMN, dorsomedial nucleus of the hypothalamus; NPY, neuropeptide Y; CTA, conditioned taste aversion; DA, dopamine; VTA, ventral tegmental area; NAc, nucleus accumbens; GABA, γ-aminobutyric acid; LMA, locomotor activity; CREB, cAMP-response element-binding protein; KO, knockout.
- Received June 2, 2006.
- Accepted July 12, 2006.
- The American Society for Pharmacology and Experimental Therapeutics
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