Abstract
The medial prefrontal cortex (PFC) and ventral tegmental area (VTA) are A_<10> systems of mesocor-ticolimbic dopamine system, which is pathophysiologically related to the model of drug dependence. Metamphetamine (MAP) was applied to examine the functional relationship between PFC and VTA in an animal of drug dependence. Hyperactivity and stereotyped behavior were observed accompanied by a distinctive direction of information flow. In hyperactivity "information flow" in the direction from PFC to VTA was dominant. Contrarily dominant "information flow" in the direction from VTA to PFC was found in stereotyped behavior. These results indicate that dysfunctional interaction between PFC and VTA is the neuronal basis of MAP-induced drug dependence. The "information flow" and its direction can be a useful tool to explain the pathogenesis of these abnormal behaviors.
