Seizure and epilepsy is a set of common neurological disorders, caused by abnormal electrical discharges of neurons. Its pathophysiological mechanisms are multiple and very complex. However, the core principle is centered around the so called hyper-excitability, which may be produced at sub-cellular, cellular or network levels.
　　This talk will first introduce basic electrophysiology of neurons, then explain the mechanisms at different levels by which the neurons or the neural networks become hyper-excitable and epileptic and, in the last part, describe the electrophysiological methods and measures that neurologists routinely use and also those newly developed to evaluate and monitor the severity of seizures and epilepsy.