The effects of levonantradol on rewarding brain stimulation thresholds in the rat

Rats were implanted bilaterally with electrodes aimed at the medial forebrain bundle (MFB) and trained to deliver intracranial stimulation. Reward thresholds were determined using a modification of the psychophysical method of limits. Levonantradol, a cannabinoid with reported analgesic activity, was tested at doses between 0.0125 to 0.3 mg/kg. Significant elevations of reward thresholds were observed at 0.2 and 0.3 mg/kg. Since none of the doses tested lowered the reward threshold, an effect believed to be predictive of abuse, these results suggest that levonantradol has little or no abuse liability.