Krystal L Parker, Kuan-Hua Chen, Johnathan R Kingyon, James F Cavanagh, Nandakumar S Narayanan

The temporal control of action is a highly conserved and critical mammalian behavior. Here, we investigate the neuronal basis of this process using an interval timing task. In rats and humans, the instructional timing cue triggered spectral power across delta and theta bands (2-6 Hz) from the medial frontal cortex (MFC). Humans and rodents with dysfunctional dopamine have impaired timing, and we found that both humans with Parkinson's disease (PD) and rodents with local MFC dopamine depletion had attenuated delta and theta activity. In rodents, spectral activity in this range could functionally couple single MFC neurons involved in temporal processing. Without MFC dopamine, these neurons had less functional coupling with delta/theta activity and less temporal processing. Finally, in humans this 2-6 Hz activity was correlated with executive function in matched controls but not in PD patients. Collectively these findings suggest that cue-evoked low-frequency rhythms could be a clinically important biomarker of PD that is translatable to rodent models, facilitating mechanistic inquiry and the development of neurophysiological biomarkers for human disease.