In this talk, Dr. Bryan Klassen explains how neurosurgeons and neurologists use intraoperative electrophysiology to precisely target deep brain stimulation (DBS) electrodes—structures as small as a pea, with subregions even smaller. He demonstrates how microelectrode recordings allow the surgical team to detect single‑neuron activity, map borders between white and gray matter, identify motor and sensory representations, and even capture disease‑specific firing patterns like tremor‑synchronized