Telemetry electroencephalograph changes of temporal association cortex in heroin-induced conditioned place preference rats

Abstract

To analyze the relationship between the electroencephalograph (EEG) changes of temporal association cortex (TeA) and the drug-seeking behavior in heroin-induced conditioned place preference (CPP) rats. The rats were randomly divided into an operated control group and a heroin-induced CPP group after the electrodes were buried in TeA by stereotactic technology. The TeA EEG was recorded by the CPP video system combining with the EEG wireless telemetry, where the rats stayed in black or white chambers, shuttling from black to white chambers or from white to black chambers. Compared with the operated control group, the percentage of TeA θ waves was increased significantly when staying in black or white chambers in the heroin-induced CPP group (P<0.05, P<0.01). Compared with the operated control group, when rats shuttling between the 2 chambers, the TeA δ waves were reduced (P<0.01), but β waves, β2 waves in particular, were increased (P<0.01) in the heroin-induced CPP group (P<0.05, P<0.01). Compared with staying in the black chamber, when heroin-induced CPP rats were shuttling between black and white chambers, the right TeA θ waves were reduced, and β waves, β2 waves in particular, were increased (P<0.01). Compared staying in the white chamber with shuttling between white and black chambers in the heroin induced CPP rats, the right TeA θ waves, but not β waves, were reduced (P<0.01). The EGG changes on the right TeA in the heroin-induced CPP rats, including the increased fast waves (β, β2) and the reduced slow wave (θ), may be related to drug-seeking behaviors.