Short history of cellular electrophysiology

According to Merriam-Websters Unabridged Dictionary electrophysiology is defined as
“the branch of physiology which treats of electrical phenomena produced by or in living organisms”.

These natural electrical phenomena in living organisms and their relationship to biological characteristics or behaviour phenomena attracted the interest of many scientists since Galvani published his impressive experiments with frog’s legs in 1791. [http://www.epub.org.br/cm/n06/historia/bioelectr2_i.htm]

The earliest founder of modern electrophysiology was Emil Heinrich du Bois-Reymonds
(1848 - 1884), who for the first time measured cellular currents.

Following a series of landmark studies in the squid axon in the early 1950’s, A.L. Hodgkin and A.F. Huxley introduced a pioneering and still valid model of the basis of nerve electrical activity. They described the cellular currents by the concerted action of voltage-gated and ion-selective membrane channels, for which they received the Nobel prize in 1963.

Inventing the patch-clamping method, E. Neher and B. Sakman were able to study this currents at the level of individual membrane proteins, for which they received the Nobel Prize for Physiology or Medicine in 1991 (). The patch-clamp technique led to many important discoveries about neuronal function and revolutionized the electrophysiological investigation of the nervous system.

Nowadays more than 400 ion channel genes are identified (Venter et al., 2001). While an increasing number of diseases has been shown to be related to dysfunction of this membrane proteins (Lehmann-Horn & Jurkat-Rott, 1999, Willumsen et al., 2003), and a large number of drugs affects the function of ion channels, drug discovery nowadays is closely related with the screening of large numbers of compounds against multiple ion channel targets.

The resulting need for appropriate test assays has forced the ongoing development of electrophysiological methods, instrumentation and cell- and tissue based assays that enable parallel and automated monitoring of ion channel activity as a measure for the pharmacological activity of a compound (Owen 2002).

Hodgkin, A.L., & Huxley, A.F. (1952). A quantitative description of membrane current and its application to conduction and excitation in nerve. J.Physiol., 117, 500-544.

Lehmann-Horn, F., & Jurkat-Rott, K. (1999). Voltage-gated ion channels and hereditary disease. Physiol.Rev., 79 (4), 1317-1372.

Neher, E. (1992). Ion channels for communication between and within cells (Nobel Lec-ture). Neuron, 8, 605-612.

Owen, D., & Silverthorne, A. (2002). Channelling drug discovery. Current trends in ion channel drug discovery research. Drug Discovery World, 3 (2), 48-61.

Venter, J.C., et al. (2001). The sequence of the human genome. Science, 291 (5507), 1304-1351.

Willumsen, N.J., Bech, M., Olesen, S.-P., Jensen, B.S., Korsgaard, M.P.G., & Chris-tophersen, P. (2003). High throughput electrophysiology: New perspectives for ion channel drug discovery. Receptors and Channels, 9 (1), 3-12.

Useful Electrophysiology Links

Historical overview of electrophysiology, membrane biophysics and patch clamp
http://www.sfn.org/wrensite/projects/patch_clamp/index.htm

Ion Channels in Biological Membranes – A brief introduction to ion channels in biological membranes, ion channels
http://www.chemsoc.org/exemplarchem/entries/2002/Tim_Smith/

Basic Electrophysiology, by Gary S. Aston-Jones and George R. Siggins
http://www.acnp.org/g4/GN401000005/Default.htm

Textbook and simulations on electrophysiology and the molecular basis of excitability by F. Bezanilla
http://pb010.anes.ucla.edu/

Channels, Receptors, and Transporters (Biophysics Textbook)
http://www.biophysics.org/btol/channel.html