First Author | Wang L | Year | 2003 |
Journal | Proc Natl Acad Sci U S A | Volume | 100 |
Issue | 3 | Pages | 1393-8 |
PubMed ID | 12538878 | Mgi Jnum | J:81844 |
Mgi Id | MGI:2450067 | Doi | 10.1073/pnas.0336351100 |
Citation | Wang L, et al. (2003) Endocannabinoid signaling via cannabinoid receptor 1 is involved in ethanol preference and its age-dependent decline in mice. Proc Natl Acad Sci U S A 100(3):1393-8 |
abstractText | Cannabinoids and ethanol can activate the same reward pathways, which could suggest endocannabinoid involvement in the rewarding effects of ethanol. The high ethanol preference of young (6-10 weeks) C57BL6J mice is reduced by the cannabinoid receptor 1 (CB1) antagonist SR141716A to levels observed in their CB1 knockout littermates or in old (26-48 weeks) wild-type mice, in both of which ethanol preference is unaffected by SR141716A. Similarly, SR141716A inhibits food intake in food-restricted young, but not old, wild-type mice. There are no age-dependent differences in the tissue levels of the endocannabinoids anandamide and 2-arachidonoylglycerol or the density of CB1 in the hypothalamus, limbic forebrain, amygdala, and cerebellum. CB1-stimulated guanosine 5'-[gamma-thio]triphosphate (GTP[gammaS]) binding is selectively reduced in the limbic forebrain of old compared with young wild-type mice. There is no age-dependent difference in G(i) or G(o) subunit protein expression in the limbic forebrain, and the selective reduction in GTP[gammaS] labeling in tissue from old mice is maintained in a receptorG protein reconstitution assay by using functional bovine brain G protein. These findings suggest that endocannabinoids acting at CB1 contribute to ethanol preference, and decreased coupling of CB1 to G proteins in the limbic forebrain by mechanisms other than altered receptor or G protein levels may be involved in the age-dependent decline in the appetite for both ethanol and food. |