when tested alone. JZL184 dose choice was based upon our prior work with this compound (Long et al., 2009a). After this set of tests was completed, the rats were retrained at 1 mg/kg THC until criteria as described above were met, and retested with THC (0.01–10 mg/kg) and URB597 (3–56 mg/kg). For all rat drug discrimination experiments, THC and its vehicle were given i.p. in a volume equivalent to 1 ml/kg body weight 30 min pre-session; URB597 and its vehicle were injected i.p. in a volume equivalent to 3 ml/kg and were administered 120 min pre-session. JZL184 and its vehicle were injected i.p. in a volume of 1 ml/kg and administered 120 min pre-session.
