Neurophysiology is a branch of physiology and neuroscience that studies nervous system function rather than nervous system architecture. This area aids in the diagnosis and monitoring of neurological diseases. Historically, it has been dominated by electrophysiology—the electrical recording of neural activity ranging from the molar to the cellular , such as patch clamp, voltage clamp, extracellular single-unit recording and recording of local field potentials. However, since the neuron is an electrochemical machine, it is difficult to isolate electrical events from the metabolic and molecular processes that cause them. Thus, neurophysiologists currently utilise tools from chemistry , physics , and molecular biology to examine brain activity.