Meeting Abstract

25.5  Friday, Jan. 4  Differential Response To A Selective Cannabinoid Receptor Antagonist In Mice Bred For High Voluntary Wheel-Running Behavior. KEENEY, B. K.*; RAICHLEN, D.A.; MEEK, T.H.; WIJERATNE, R.S.; GERDEMAN, G.L.; GARLAND, T. Jr.; University of California, Riverside; University of Arizona; University of California, Riverside; University of California, Riverside; University of Arizona; University of California, Riverside bkeen001@ucr.edu

The endocannabinoid system may play an important role in the physiological response to exercise. Endocannabinoid signaling is activated by aerobic exercise in humans and is associated with both neurobiological rewards and analgesia. Thus, endocannabinoid signaling may provide a motivation for, and an ability to maintain sustained exercise. In this study, we tested the hypothesis that the locomotor response to Rimonabant (SR141716), a selective cannabinoid receptor antagonist, would be altered in mice selectively bred for high voluntary wheel-running behavior. We predicted that mice from four replicate selected lines would show a differential response to Rimonabant, as compared with four non-selected control lines. Drug trials were conducted on mice of both sexes from generation 48, at night during peak activity, after eighteen days of habituation to wheel-cages. Each mouse received in a randomized order; low dose Rimonabant, high dose Rimonabant, or sham, over a period of 9 days. Drug response was quantified as wheel revolutions 10-70 minutes post-injection. Rimonabant decreased wheel-running in all mice; however, the dose-by-linetype interaction was statistically significant for females but not males. These results suggest an association between sex, wheel-running behavior, and the endocannabinoid system. Supported by NSF IOB-0543429 to T.G.