The dopamine-containing neurons of the midbrain ventral tegmental area (VTA) play a critical role in the reinforcing effects of drugs of abuse.It has long been known that morphine can excite dopamine (DA) neurons in ventral tegmental area (VTA) by increasing both firing rate and burst activity.Nevertheless, great deal of evidences indicates that DA cells are not immediately influenced by morphine, the effects are through a rather complicated circuit such as morphine-mediated disinhibition from other neurons.Previous works have demonstrated that the prefrontal cortex (PFC) terminals project to the dendrites of DA and non-DA neurons in the VTA, and PFC-VTA circuit controls the majority of information flowing into VTA and plays essential role in drug addiction.However, how PFC involves in the regulation of DA neuron activity in response to addictive drug remains largely unknown.