Therefore, the high-frequency stimulation of the subthalamic nucleus may indeed engage the cerebellum, decreasing spiking activity in Purkinje cells and increasing deep cerebellar nuclei spiking activity (Sutton et al. 2015) and c-Fos expression (Moers-Hornikx et al. 2011) raising the possibility that STN stimulations could directly impact cerebellar function in PD. Here, FOS is linked to Parkinson disease.