Self-Administration of JWH-018 A Synthetic Cannabinoid in Experimentally Naïve Rats

A recent study by Dr. Maria Antonietta De Luca demonstrated intravenous (IV) self-administration responding (nose-poking) for the synthetic cannabinoid JWH-018 [1-pentyl-3-(1-naphthoyl)indole] (Figure 1) in an experimentally naïve, adult rat species [1]. This finding is unexpected since the phytocannabinoid (−)-trans-Δ9tetrahydrocannabinol (Δ9-THC, Figure 1), a primary psychoactive constituent in marijuana, has been reported to not maintain IV selfadministration responding above vehicle levels in rats [2,3] and rhesus monkeys [4-6]. IV self-administration of synthetic cannabinoids is not unprecedented since several synthetic cannabinoids have been found to maintain IV self-administration responding in experimentally naïve rats [1,7-10], and mice [11-14]. However, the finding by Dr. De Luca is important because JWH-018 has been frequently found in K2/Spice preparations [15-17] and there continues to be an increase in the abuse and non-medical use of various synthetic cannabinoids worldwide [15-17]. Further, the use of marijuana has been recently legalized in two states of the U.S.