High efficient electrical stimulation of hippocampal slices with vertically aligned carbon nanofiber microbrush array.
Long-term neuroprostheses for functional electrical stimulation must efficiently stimulate tissue without electrolyzing water and raising the extracellular pH to toxic levels. Comparison of the stimulation efficiency of tungsten wire electrodes (W wires), platinum microelectrode arrays (PtMEA), as-grown vertically aligned carbon nanofiber microbrush arrays (VACNF MBAs), and polypyrrole coated (PPy-coated) VACNF MBAs in eliciting field potentials in the hippocampus slice indicates that, at low stimulating voltages that preclude the electrolysis of water, only the PPy-coated VACNF MBA is able to stimulate the CA3 to CA1 pathway. Unlike the W wires, PtMEA, as-grown VACNF MBA, and the PPy-coated VACNF MBA elicit only excitatory postsynaptic potentials (EPSPs). Furthermore, the PPy-coated VACNF MBA evokes somatic action potentials in addition to EPSPs. These results highlight the PPy-coated VACNF's advantages in lower electrode impedance, ability to stimulate tissue through a biocompatible chloride flux, and stable vertical alignment in liquid that enables access to spatially confined regions of neuronal cells.
de Asis
Edward D
ED
Department of Electrical Engineering, Santa Clara University, 500 El Camino Real, Santa Clara, CA 95053, USA.
Nguyen-Vu
T D Barbara
TD
Arumugam
Prabhu U
PU
Chen
Hua
H
Cassell
Alan M
AM
Andrews
Russell J
RJ
Yang
Cary Y
CY
Li
Jun
J
D000200:Action Potentials; D000818:Animals; D002244:Carbon; D046690:Deep Brain Stimulation / Q000295:instrumentation* / Q000379:methods*; D017097:Electric Impedance; D006624:Hippocampus; D006801:Humans; D008297:Male; D042282:Microdissection; D008839:Microelectrodes; D049329:Nanostructures; D051381:Rats; D017208:Rats, Wistar
D002244:Carbon