Evaluation of reinforcing capability of delta-9-tetrahydrocannabinol in rhesus monkeys

Self-administration of cannabinoids by experimental animals and human marijuana smokers

“…Over the last three decades, many attempts to demonstrate intravenous self-administration of THC or of synthetic cannabinoid CB 1 receptor agonists by experimental animals were relatively unsuccessful (Pickens et al, 1973;Kaymakcalan, 1973;Harris et al, 1974;Carney et al, 1977;van Ree et al, 1978;Mansbach et al, 1994) (Table 1). None of these studies clearly demonstrated persistent, dose-related, self-administration behavior maintained by THC or synthetic cannabinoids, which would be susceptible to vehicle extinction and subsequent reinstatement in the absence of unusual "foreign" conditions.…”

“…This was unlikely, since earlier attempts to obtain THC selfadministration behavior in monkeys with a previous cocaine self-administration experience had been unsuccessful, even when THC was directly substituted for cocaine with no intervening vehicle extinction (Harris et al, 1974). However, we resolved this issue in a recent study with squirrel monkeys that were experimentally and drug naive at the start of the experiments (Justinova et al, 2003).…”

“…A potential explanation for these observed effects is that ketamine and dextrorphan share some discriminative-stimulus effects (Holtzman, 1980;Herling et al, 1981), as do diazepam and pentobarbital (Colpaert et al, 1976;Shannon and Herling, 1983). However, attempts to directly substitute THC for drugs thought to have some discriminative-stimulus effects in common with THC (such as phencyclidine, phenobarbital or ethanol) have been unsuccessful in generating THC self-administration behavior (Harris et al, 1974;Mansbach et al, 1994).…”

Reduction of opioid dependence by the CB1 antagonist SR141716A in mice: evaluation of the interest in pharmacotherapy of opioid addiction

“…Another hypothesis to explain the results obtained is the existence of an endogenous cannabinoid tone, as several authors observed that CB 1 agonists are able to induce a place preference (Lepore et al, 1995;Valjent & Maldonado, 2000). However, it is important to note that the rewarding eects of cannabinoids in the dierent animals models currently used are controversial and may strongly depend in part of the species and treatments used (Harris et al, 1974;Mansbach et al, 1994). Thus, cannabinoid agonists failed to induce self-administration behaviour in monkeys or rats (Leite & Carlini, 1974), but are self-administered in mice (Martellota et al, 1998).…”

Animal Models of Drug Self-Administration by Smoking

“…The consistent increases in the rate of the spaced responding performance that occurred immediately following the smoking sessions with THC in the cigarette were consistent with drug intake, but the dose effect functions were equivocal. IV self-administration of delta-9-THC is difficult to engender as evidenced by the heroic but unsuccessful effort of Harris et al (1974). Pickens et al (1973) induced IV delta-9-THC self-administration in animals with a recent history of phencyclidine self-administration.…”