Δ9-THC (50 mg/ml in ethanol solution) was evaporated under nitrogen gas, dissolved in 0.9% NaCl (saline) containing 0.3% Tween 80 to a concentration of 0.75 mg/ml (Dinieri and Hurd, 2012). Control “vehicle” (VEH) solution was saline containing 0.3% Tween 80.