Abstract: Objective To investigate the changes of telemetry electrical activity in the infralimbic cortex (IL) of morphinedependent
rats with extinguished drug-seeking behavior. Methods SD rats were randomly divided into model group and
control group and received operations of brain stereotaxic electrode embedding in the IL. The rats in the model group were
induced to acquire morphine dependence and then received subsequent extinction training, and the changes of electrical
activity in the IL were recorded with a physical wireless telemetry system. Results In rats with morphine dependence, the time
staying in the white box was significantly longer on days 1 and 2 after withdrawal than that before morphine injection and that
of the control rats, but was obviously reduced on days 1 and 2 after extinction training to the control level. Compared with the
control group, the morphine-dependent rats on day 2 following withdrawal showed significantly increased β wave and
decreased δ wave when they stayed in the white box but significantly increased δ wave and decreased α wave and β wave
when they shuttled from the black to the white box. On day 2 of extinction, the model rats, when staying in the white box,
showed significantly decreased θ wave compared with that of the control rats group but decreased β wave and θ wave and
increased δ wave compared with those in the withdrawal period. When they shuttled from black to white box, the model rats
showed decreased δ wave and increased α wave and β wave compared with those in the withdrawal period. Conclusion
Morphine-dependent rats have abnormal changes of electrical activity in the IL in drug-seeking extinction to affect their
drug-seeking motive and inhibit the expression and maintenance of drug-seeking behaviors.