Identification and functional characterization of brainstem cannabinoid CB2 receptors.
Science (New York, N.Y.) 2005 Oct 14; 310(5746):329-32
Van Sickle M MD, Duncan M M, Kingsley P PJ, Mouihate A A, Urbani P P, Mackie K K, Stella N N, Makriyannis A A, Piomelli D D, Davison J JS, Marnett L LJ, Di Marzo V V, Pittman Q QJ, Patel K KD, Sharkey K KA
Institute of Infection, Immunity, and Inflammation and Hotchkiss Brain Institute, Department of Physiology and Biophysics, University of Calgary, Calgary, AB, Canada T2N 4N1.
The presence and function of CB2 receptors in central nervous system (CNS) neurons are controversial. We report the expression of CB2 receptor messenger RNA and protein localization on brainstem neurons. These functional CB2 receptors in the brainstem were activated by a CB2 receptor agonist, 2-arachidonoylglycerol, and by elevated endogenous levels of endocannabinoids, which also act at CB1 receptors. CB2 receptors represent an alternative site of action of endocannabinoids that opens the possibility of nonpsychotropic therapeutic interventions using enhanced endocannabinoid levels in localized brain areas.