Extracellular field potential 512512 135374726 2007-06-02T19:13:17Z Clicketyclack 734918 cat sorting & links The '''extracellular field potential''' is the [[electrical potential]] produced by [[Cell (biology)|cell]]s, e.g. [[Neuron|nerve]] or [[Muscle fiber|muscle cell]]s, outside of the cell. [[Electrophysiology|Electrophysiological studies]] investigate these potentials using extracellular [[microelectrode]]s. In these experiments the extracellular field potential will be detected as an electrical potential whose source and composition is often ambiguous, making its interpretation difficult. Individual nerve cells [[neuron]]s may produce [[spike]]s seen as peaks of some tens to hundreds of microvolts. Contributions from neighbouring neurons may overlap, producing extracellular potentials of up to several millivolts. Spatially integrating over even larger populations of cells, i.e. lumps of [[nervous tissue|nervous]] or [[muscle|muscular tissue]], will produce signals commonly called [[local field potential]]s (LFP) that can be recorded with suitable equipment at the body surface as, e.g., [[electroencephalogram]] (EEG), [[electrocardiogram]] (ECG), or [[electromyogram]] (EMG). For individual cells, the time course of the extracellular potential theoretically is inversely proportional to the transmembrane current. In practice, however, this is complicated considerably by the very complex [[Morphology (biology)|morphology]] of neurons and the overlap of contributions from adjacent cells. [[Category:Cell biology]] [[Category:Electrochemistry]] [[Category:Electrophysiology]] [[Category:Membrane biology]] [[Category:Physical quantity]] {{biology-stub}}