Abstract
Activation of the medial prefrontal cortex (mPFC) is required for hyperlocomotion and expression of c-fos gene in the subthalamic nucleus (STN) in response to systemic dopamine stimulation. These reactions are mediated by dopamine D1-like and D2-like receptors in the mPFC. In the present study, we tested the possibility that the functional connectivity between the mPFC and STN may be involved in dopamine-induced motor behavior. When a retrograde tracer FluoroGold (FG) was injected into the STN, the labeled signals were observed in the mPFC pyramidal cells. Intra-mPFC injection of biotin dextran amine gave anterogradely labeled fibers innervating the STN. Systemic injection of methamphetamine (METH) elicited c-fos expression in glutamatergic projection neurons but not in GABAergic interneurons in the mPFC. Some of c-fos-positive neurons in the mPFC were retrogradely labeled by FG injection into the STN, indicating that the mPFC neurons activated by METH monosynaptically innervate the STN. These results suggest that the mPFC neurons act to facilitate dopamine-induced hyperlocomotion through the corticosubthalamic neural pathway. [J Physiol Sci. 2007;57 Suppl:S163]
