∆-9-TETRAHYDROCANNABINOL DOES NOT DIFFERENTIALLY INDUCE AVERSIONS IN THE FISCHER (F344) and LEWIS (LEW) RAT STRAINS

Although Fischer (F344) and Lewis (LEW) rats differ in their sensitivity to the rewarding effects of THC, no data have been reported on differences in their sensitivity to the drug's aversive effects, a limiting factor in drug use and abuse. Examining the degree of differences (if any) in such effects in these strains may help further characterize possible genetic factors important to abuse vulnerability. Accordingly, the aversive effects of THC were examined in 32 F344 and 32 LEW (THC; 0.0, 1.0, 3.2, 5.6 mg/kg) subjects using the conditioned taste aversion procedure. Thermoregulation was assessed following an acute injection of THC (same as CTA groups) after a week washout period following the last trial. Subjects in both strains displayed dose-dependent THC-induced taste aversions, with no significant strain difference. Core body temperatures of F344 subjects were significantly higher than LEW rats, although these differences were independent of THC (which itself induced hypothermia in both strains). These results were discussed in terms of the nature of THC-induced aversions and the basis of strain differences in the aversive effects of drugs of abuse.