The effects of cannabinoid agonism on auditory discrimination.

Cannabinoid agonism via WIN 55,212-2 did not impair auditory discrimination in rats. Twenty-two rats were trained to press a lever for sucrose in response to either a pure tone or white noise, with correct responses reinforced and incorrect ones punished. After reaching criterion, they received 1.2 mg/kg, 3 mg/kg, or saline. On day 3, active lever-pressing was higher in both dose groups compared to saline, but overall pressing decreased over time in the high-dose group. No effects on discrimination or errors were observed, indicating that cannabinoid agonism did not negatively affect auditory discrimination, contrary to some previous findings.

Study at a glance

Abstract

Recent evidence suggests that cannabis can impair simple auditory processes, and these alterations might be due to cannabinoid agonism. The effect of cannabinoid agonism on relatively complex processes such as auditory discrimination is unknown. The goal of this study was to examine the impact of WIN 55,212-2, a CB 1 receptor and CB 2 receptor agonism, on auditory discrimination using a go/no-go task. Twenty-two male and female Sprague-Dawley rats were initially trained to lever-press for sucrose to either a pure tone or white noise cue in a go/no-go paradigm, where rats were reinforced for lever-pressing during one cue and punished for lever-pressing during the other auditory cue. After criterion performance was met, rats were then injected with WIN 55,212-2 at 1.2 mg/kg, 3 mg/kg, or a corresponding vehicle (saline) and were tested on auditory discrimination. On day 3, active lever-pressing was higher in both the low- and high-dose WIN groups compared with the saline group. Overall lever-pressing decreased over time in the high-dose WIN 55,212-2 group. There were no effects of the drug on discrimination or errors, suggesting that cannabinoid agonism did not negatively affect auditory discrimination. This is the first study to examine the impact of cannabinoids on the discrimination of tones, finding that, contrary to previous research, the low and high doses of WIN 55,212-2 did not adversely impact auditory-linked behaviors.