QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

HOME  |   SEARCH  |   ARCHIVE  |   SUBSCRIBE  |   CONTACT  |   HELP

The Journal of Neuroscience, March 14, 2007, 27(11):3030-3036; doi:10.1523/JNEUROSCI.0095-07.2007

This Article Full Text Full Text (PDF) Supplemental Data Submit an eLetter View eLetters for this paper Alert me when this article is cited Alert me when eLetters are posted Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in ISI Web of Science Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via ISI Web of Science (2) Citing Articles via Google Scholar Google Scholar Articles by Radman, T. Articles by Bikson, M. Search for Related Content PubMed PubMed Citation Articles by Radman, T. Articles by Bikson, M.

 Previous Article  |  Next Article 

Behavioral/Systems/Cognitive
Spike Timing Amplifies the Effect of Electric Fields on Neurons: Implications for Endogenous Field Effects

Thomas Radman, Yuzhuo Su, Je Hi An, Lucas C. Parra, ^* and Marom Bikson ^*

Department of Biomedical Engineering, City College of the City University of New York, New York, New York 10031

Correspondence should be addressed to Marom Bikson, T-403B, Steinmann Hall, Department of Biomedical Engineering, City College of New York, 140th Street and Convent Avenue, New York, NY 10031. Email: bikson{at}ccny.cuny.edu

Despite compelling phenomenological evidence that small electric fields (<5 mV/mm) can affect brain function, a quantitative and experimentally verified theory is currently lacking. Here we demonstrate a novel mechanism by which the nonlinear properties of single neurons "amplify" the effect of small electric fields: when concurrent to suprathreshold synaptic input, small electric fields can have significant effects on spike timing. For low-frequency fields, our theory predicts a linear dependency of spike timing changes on field strength. For high-frequency fields (relative to the synaptic input), the theory predicts coherent firing, with mean firing phase and coherence each increasing monotonically with field strength. Importantly, in both cases, the effects of fields on spike timing are amplified with decreasing synaptic input slope and increased cell susceptibility (millivolt membrane polarization per field amplitude). We confirmed these predictions experimentally using CA1 hippocampal neurons in vitro exposed to static (direct current) and oscillating (alternating current) uniform electric fields. In addition, we develop a robust method to quantify cell susceptibility using spike timing. Our results provide a precise mechanism for a functional role of endogenous field oscillations (e.g., gamma) in brain function and introduce a framework for considering the effects of environmental fields and design of low-intensity therapeutic neurostimulation technologies.

Key words: electromagnetic field; hippocampus; electrical stimulation; frequency; gamma; coherence

---

Received Jan. 9, 2007; revised Feb. 9, 2007; accepted Feb. 12, 2007.

Correspondence should be addressed to Marom Bikson, T-403B, Steinmann Hall, Department of Biomedical Engineering, City College of New York, 140th Street and Convent Avenue, New York, NY 10031. Email: bikson{at}ccny.cuny.edu

This article has been cited by other articles:

				S. A. Weiss, T. Preuss, and D. S. Faber A role of electrical inhibition in sensorimotor integration PNAS, November 18, 2008; 105(46): 18047 - 18052. [Abstract] [Full Text] [PDF]

				T. Radman, A. Datta, and A. V. Peterchev In vitro modulation of endogenous rhythms by AC electric fields: Syncing with clinical brain stimulation J. Physiol., October 15, 2007; 584(2): 369 - 370. [Full Text] [PDF]

eLetters:

Read all eLetters

Is the EEG an epiphenomenon?

David M. Alexander

J. Neurosci. Online, 21 Oct 2007 [Full text]

Home  |   Search  |   Archive  |   Subscribe  |   Contact  |   Help