Abstract:
Dr. Ikemoto presents recent findings from his lab concerning motivational role of the medial prefrontal cortex (MPFC). The MPFC regulates motivation, and has been implicated in psychiatric disorders such as depression and addiction. However, little is known about circuits through which the MPFC regulates motivation. Optogenetic stimulation of the MPFC induced positive emotional arousal as shown by intracranial self-stimulation. fMRI revealed that such stimulation activated MPFC projection regions including the striatum, thalamus, and hypothalamus. Additional data suggest that the positive motivational effect induced by MPFC stimulation is partly mediated by striatal neurons projecting to the substantia nigra pars reticulata. The implications of these findings are discussed with respect to deep brain stimulation applied at the MPFC for the treatment of major depression.