[Neuroscience] Re: Effects of weak electric fields on the activity
of neurons and neuronal networks
(by andy.resnick from op.case.edu)
Tue Nov 6 09:28:15 EST 2007
> if you want the full text, you'll have to pay for it...
> Radiation Protection Dosimetry 106:321-323 (2003)
> © 2003 Oxford University Press
> Effects of weak electric fields on the activity of neurons and
> neuronal networks
> J.G.R. Jefferys, J. Deans, M. Bikson and J. Fox
> Electric fields applied to brain tissue will affect cellular
> properties. They will hyperpolarise the ends of cells closest to the
> positive part of the field, and depolarise ends closest to the
> negative. In the case of neurons this affects excitability. How these
> changes in transmembrane potential are distributed depends on the
> length constant of the neuron, and on its geometry; if the neuron is
> electrically compact, the change in transmembrane potential becomes an
> almost linear function of distance in the direction of the field.
> Neurons from the mammalian hippocampus, maintained in tissue slices in
> vitro, are significantly affected by fields of around 1-5 Vm-1.
Remarkable. They present no actual data, summarize previous results
with no way to decipher what was actually done, and make numerous
"More importantly, we were able to measure that transmembrane
potential at the cell body changed by an average
of 0.12 mV for each V m1 of applied field(16)A"
AFAIK, the action potential is around 100 mV- so they claim a 0.1%
effect is meaningful and statistically significant.
But it *is* open source, so some would say this is a model effort.
Andrew Resnick, Ph.D.
Department of Physiology and Biophysics
Case Western Reserve University
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