Abstract
Dopaminergic (DAergic) system in the medial prefrontal cortex (mPFC) is involved in cognition, memory, and behavioral control. Although the dysfunction of the DAergic system is suggested to cause several mood disorder and schizophrenia, the neural mechanisms for behavioral control through the interaction between the mPFC and the basal ganglia remain to be unclear. To elucidate this issue, we examined the effects of blockade of DAergic transmission in the mPFC of C57/BL6J mice during methamphetamine (METH)-induced hyperlocomotion. When mice received intra-mPFC infusions of muscimol, a GABAA receptor agonist, METH-induced hyperlocomotion was significantly reduced. Infusions of SCH23390, a D1 DA receptor antagonist, and sulpiride, a D2 DA receptor antagonist, also decreased their locomotion. Although METH induced c-fos expression in the subthalamic nucleus (STN), these drugs infused into the mPFC significantly suppressed METH-induced STN activation. These results indicate that DAergic transmission in the mPFC during DA-induced locomotion facilitates their behavioral activity through the activation of the STN, implying that the mPFC-STN pathway contributes to DA-induced behavioral activation. [J Physiol Sci. 2006;56 Suppl:S191]
