Telemetry EEG of Parietal Association Cortex in Heroin-induced CPP Rats

Objective?To determine the relationship between EEG changes of parietal association cortex (PtA) and drug-seeking behaviors of heroin-induced conditioned place preference (CPP) rats. Methods?Stereotaxic electrode was buried in the PtA of rats, which were then divided randomly into heroin-induced CPP group and operation-only control group. A CPP video system in combination with EEG wireless telemetry was used for recording PtA EEG and the behaviors of the rats-staying in black or white chamber of the video box; shuttling between black-white chambers or between white-black chambers. Results?No significant difference in percentage of the telemetry EEG waves was found between the two groups of rats when they stayed in the black or white chambers. The heroin-induced CPP rats had increased percentage of δ waves (P<0.05) on the right PtA and decreased percentage of β and β2 waves on both right and left PtA (P<0.05) when they shuttled between two chambers. Compared with the operation-only controls, significant decrease in the percentage of δ waves on both left and right PtA and increase in θ, α and α1 waves were evident (P<0.05） only when the heroin-induced CPP rats shuttled between white-black chambers. Conclusion?EEG changes on PtA of heroin-induced CPP rats differ between staying and shuttling states. Such changes may not be associated with drug-seeking behaviors.