Spreading depression is a neurophysiological phenomenon characterized by abrupt changes in transmembrane ion gradients and sustained inactivation of neurons. One physiological phenomena that can initiate or result from SD is local cell swelling which is accompanied by a decrease in extracellular space (ECS). The goal is to develop and implement an impedance-based method that will enable the investigation of the causal role of ECS dynamics in initiating SD in different spontaneous seizure and SD dynamics.