Characterization of electrophysiological recordings during deep brain stimulation (DBS) surgery is critical for anatomical targeting and is extensively utilized to investigate physiologic markers of Parkinson’s Disease (PD). Transient improvement in clinical symptoms has been reported after microelectrode penetration, but the mechanism(s) underlying this improvement are not well understood. Thus, we sought to determine the electrophysiologic effects of microelectrode penetration in the Subthalamic Nucleus (STN).