An endogenous electrical field effect, i.e., ephaptic transmission, occurs when an electric field associated with activity occurring in one neuron polarizes the membrane of another neuron. It is well established that field effects occur during pathological conditions, such as epilepsy, but less clear if they play a functional role in the healthy brain. Here, we describe the principles of field effect interactions, discuss identified field effects in diverse brain structures from the teleost Mauthner cell to the mammalian cortex, and speculate on the function of these interactions. Recent evidence supports that relatively weak endogenous and exogenous field effects in laminar structures reach significance because they are amplified by network interactions. Such interactions may be important in rhythmogenesis for the cortical slow wave and hippocampal sharp wave–ripple, and also during transcranial stimulation.
Keywords: neurotransmission, ephaptic, field effect, LFP, computation, transcranial stimulation
Citation: Weiss SA and Faber DS (2010) Field effects in the CNS play functional roles. Front. Neural Circuits 4:15. doi: 10.3389/fncir.2010.00015
Received: 27 February 2010;
Paper pending published: 22 March 2010;
Accepted: 23 April 2010; Published online: 18 May 2010
Edited by:Ronald M. Harris-Warrick, Cornell University, USA
Reviewed by:Wolfgang Stein, Ulm University, Germany
Copyright: © 2010 Weiss and Faber. This is an open-access article subject to an exclusive license agreement between the authors and the Frontiers Research Foundation, which permits unrestricted use, distribution, and reproduction in any medium, provided the original authors and source are credited.
*Correspondence: Donald S. Faber, Department of Neuroscience, Albert Einstein College of Medicine, 1300 Morris Park Ave, Bronx, NY 10461, USA. e-mail: firstname.lastname@example.org