Microscale Inhomogeneity of Brain Tissue Distorts Electrical Signal Propagation
Abstract
Interpretations of local field potentials (LFPs) are typically shaped on an assumption that the brain is a homogenous conductive milieu. However, microscale inhomogeneities including cell bodies, dendritic structures, axonal fiber bundles and blood vessels are unequivocally present and have different conductivities and permittivities than brain extracellular fluid. To determine the extent to which these obstructions affect electrical signal propagation on a microscale, we delivered electrical stimuli intracellularly to individual cells while simultaneously recording the extracellular potentials at different locations in a rat brain slice. As compared with relatively unobstructed paths, signals were attenuated across frequencies when fiber bundles were in between the stimulated cell and the extracellular electrode. Across group of cell bodies, signals were attenuated at low frequencies, but facilitated at high frequencies. These results show that LFPs do not reflect a democratic representation of neuronal contributions, as certain neurons may contribute to the LFP more than others based on the local extracellular environment surrounding them.
Additional Information
© 2013 The Authors. Received July 22, 2012; revised Nov. 1, 2012; accepted Dec. 9, 2012. Author contributions: M.N., L.V., and P.P. designed research; M.N. and C.B. performed research; M.N. analyzed data; M.N., C.B., L.V., and P.P. wrote the paper. M.J.N. was supported by the Programme de bourses d'excellence Eiffel, and the Fonds de dotation Patrick de Brou de Laurière. The basic results here have been presented previously in abstract form (Nelson, Bosch, Venance and Pouget, 2010 Soc Neurosci Abstr).Attached Files
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Additional details
- PMCID
- PMC6619221
- Eprint ID
- 37518
- Resolver ID
- CaltechAUTHORS:20130314-110127998
- Programme de bourses d'excellence Eiffel
- Fonds de dotation Patrick Brou de Laurière
- Created
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2013-03-20Created from EPrint's datestamp field
- Updated
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2021-11-09Created from EPrint's last_modified field