Ionic charge transport between blockages: Sodium cation conduction in freshly excised bulk brain tissue.
We analyze the transient-dc and frequency-dependent electrical conductivities between blocking electrodes. We extend this analysis to measurements of ions' transport in freshly excised bulk samples of human brain tissue whose complex cellular structure produces blockages. The associated ionic charge-carrier density and diffusivity are consistent with local values for sodium cations determined non-invasively in brain tissue by MRI (NMR) and diffusion-MRI (spin-echo NMR). The characteristic separation between blockages, about 450 microns, is very much shorter than that found for sodium-doped gel proxies for brain tissue, >1 cm.
Department of Physics and Astronomy, University of New Mexico , Albuquerque, NM 87131, USA.
David
D
Emin
Semple Institutes for Neuroscience and Human Behavior, David Geffen School of Medicine, University of California at Los Angeles , Los Angeles, CA 90095, USA.
Massoud
M
Akhtari
Department of Radiology, David Geffen School of Medicine, University of California at Los Angeles , Los Angeles, CA 90095, USA.
B M
BM
Ellingson
Department of Neurosurgery, David Geffen School of Medicine, University of California at Los Angeles , Los Angeles, CA 90095, USA.
G W
GW
Mathern