Optimization of deep brain stimulation (DBS) parameters is a weeks to months-long process for many patients, due in part to the inflammatory response caused by electrode implantation. To investigate the effect of inflammation on current delivery. transgenic mice, expressing Thy1-GCaMP6f (a genetically-encoded calcium sensor), were implanted with a DBS electrode in the subthalamic nucleus (STN). Immediately following insertion, high frequency electrical stimulation of the STN was performed and we imaged changes in fluorescence elicited by stimulation to characterize the response of cortical neurons to STN DBS. Our result is consistent with the idea that the acute inflammatory response during the perioperative and early postoperative periods shunt current away from the desired target compared to the chronic inflammatory state weeks later.