PM313. Neurocognitive Examination of Inhibitory Control and Error Processing Mechanisms In Prescription Opioid Dependence

Introduction: Prescription opioid (PO) abuse is a growing public health concern worldwide as evidenced by an increasing number of opioid-related hospital admissions with a striking lack of research examining the neural basis underlying cognitive symptomology. Drugs of abuse, through their impact on the dopaminergic system, are thought to disrupt the pre-frontal cognitive network regulating impulse control through performance monitoring and inhibition of goal-oriented behaviour. The objective of the present study is to examine neurocognitive processes in PO abusers (vs. healthy controls) by relying on the enhanced temporal resolution (1ms) of event-related potentials (ERPs) to track information processing abnormalities associated with cognitive control. Methods: In a naturalistic clinical study, 20 patients actively using prescription opioids and 20 healthy controls (matched for age, gender, educational level and smoking status) were assessed using a Go/NoGo paradigm, where the response to NoGo trials was evaluated. Results: Preliminary analysis reveals significantly (p<0.05) larger N200 and P300 amplitudes in patients (vs. controls) after successful NoGo trials. The N200 is a frontally distributed negative waveform reflecting the commencement of active inhibition, whereas the P300 is a fronto-centrally distributed positive waveform reflecting the termination of a previous inhibitory process. Following unsuccessful NoGo trials, error positivity (Pe) amplitudes were also significantly (p<0.05) increased in patients (vs. controls). The Pe is a fronto-central positive deflection component of the ERP representing the awareness of conscious error processing. Conclusions: These ERP results of altered cognitive control and error processing suggest the neural mechanisms underlying these cognitions are affected by chronic opioid abuse. Investigating the cognitive abnormalities experienced by PO abusers is an important factor in understanding the neural correlates of substance abuse and in predicting successful outcomes to ensure the best chance at long-term recovery for addicted individuals. Research funded by a Canadian Institute of Health Research (CIHR) grant. PM314 Knockdown Piccolo suppressed Methamphetamineinduced behavioral changes and dopamine release in the nucleus accumbens of mice Bin Ge1, Seiya Morishita1, Kyosuke Uno1, Shin-ichi Muramatsu2, Toshitaka Nabeshima, Yoshiaki Miyamoto 1, Atsumi Nitta1 1Department of Pharmaceutical Therapy and Neuropharmacology, Faculty of Pharmaceutical Sciences, Graduate School of Medicine and Pharmaceutical Sciences, University of Toyama, Toyama 930-0194, JAPAN 2Division of Neurology, Department of Medicine, Jichi Medical University, Shimotsuke 329–0498, JAPAN 3Meijo Uiversity, Nagoya