Linked Life Data

14990509

Source:http://linkedlifedata.com/resource/pubmed/id/14990509

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
3
pubmed:dateCreated
2004-3-1
pubmed:abstractText
Extracellular local field potentials are usually modeled as arising from a set of current sources embedded in a homogeneous extracellular medium. Although this formalism can successfully model several properties of extracellular local field potentials, it does not account for their frequency-dependent attenuation with distance, a property essential to correctly model extracellular spikes. Here we derive expressions for the extracellular potential that include this frequency-dependent attenuation. We first show that, if the extracellular conductivity is nonhomogeneous, there is induction of nonhomogeneous charge densities that may result in a low-pass filter. We next derive a simplified model consisting of a punctual (or spherical) current source with spherically symmetric conductivity/permittivity gradients around the source. We analyze the effect of different radial profiles of conductivity and permittivity on the frequency-filtering behavior of this model. We show that this simple model generally displays low-pass filtering behavior, in which fast electrical events (such as Na(+)-mediated action potentials) attenuate very steeply with distance, whereas slower (K(+)-mediated) events propagate over larger distances in extracellular space, in qualitative agreement with experimental observations. This simple model can be used to obtain frequency-dependent extracellular field potentials without taking into account explicitly the complex folding of extracellular space.
pubmed:commentsCorrections
http://linkedlifedata.com/resource/pubmed/commentcorrection/14990509-10200189, http://linkedlifedata.com/resource/pubmed/commentcorrection/14990509-10341257, http://linkedlifedata.com/resource/pubmed/commentcorrection/14990509-11701517, http://linkedlifedata.com/resource/pubmed/commentcorrection/14990509-12445898, http://linkedlifedata.com/resource/pubmed/commentcorrection/14990509-12991237, http://linkedlifedata.com/resource/pubmed/commentcorrection/14990509-13990734, http://linkedlifedata.com/resource/pubmed/commentcorrection/14990509-14237212, http://linkedlifedata.com/resource/pubmed/commentcorrection/14990509-2286094, http://linkedlifedata.com/resource/pubmed/commentcorrection/14990509-4161316, http://linkedlifedata.com/resource/pubmed/commentcorrection/14990509-4161317, http://linkedlifedata.com/resource/pubmed/commentcorrection/14990509-5710539, http://linkedlifedata.com/resource/pubmed/commentcorrection/14990509-874533, http://linkedlifedata.com/resource/pubmed/commentcorrection/14990509-9248061, http://linkedlifedata.com/resource/pubmed/commentcorrection/14990509-9787013
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:status
MEDLINE
pubmed:month
Mar
pubmed:issn
0006-3495
pubmed:author
pubmed:issnType
Print
pubmed:volume
86
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
1829-42
pubmed:dateRevised
2009-11-18
pubmed:meshHeading
pubmed:year
2004
pubmed:articleTitle
Modeling extracellular field potentials and the frequency-filtering properties of extracellular space.
pubmed:affiliation
Département de Physique, Université Laval, Québec, Québec G1K 7P4, Canada.
pubmed:publicationType
Journal Article, Comparative Study, Research Support, Non-U.S. Gov't, Evaluation Studies, Validation Studies