Sensory gating impairments in heavy cannabis users are associated with altered neural oscillations.

Central cannabinoid receptors mediate neural oscillations and are localized to networks implicated in auditory P50 sensory gating, including the hippocampus and neocortex. The current study examined whether neural oscillations evoked by the paired clicks (S1, S2) are associated with abnormal P50 gating reported in cannabis users. Seventeen heavy cannabis users and 16 cannabis naïve controls participated. Analyses included P50 amplitudes, and time-frequency analyses (event-related spectral perturbations, ERSPs; intertrial coherence, ITC). Consistent with prior studies, cannabis users exhibited reduced P50 gating. The ERSP analysis yielded attenuated high frequency activity in the beta range (13-29 Hz) post-S1 and in the gamma range (30-50 Hz) post-S2 in the cannabis group, compared with the control group. Greater levels of cannabis use were positively associated with high P50 ratios and negatively with post-S2 ERSP gamma power. Findings suggest that heavy cannabis use is associated with aberrant beta and gamma activity in the dual-click procedure, which corroborates recent work demonstrating disruption of beta/gamma by cannabinoid receptor (CB1) agonists in a rat analogue of this task and highlights the translational potential of the dual-click procedure [corrected] 2009 APA, all rights reserved