Selective microstimulation of central nervous system neurons.

Journal Article (Journal Article)

The goal of this study was to identify stimulus parameters and electrode geometries that were effective in selectively stimulating targeted neuronal populations within the central nervous system (CNS). Cable models of neurons that included an axon, initial segment, soma, and branching dendritic tree, with geometries and membrane dynamics derived from mammalian motoneurons, were used to study excitation with extracellular electrodes. The models reproduced a wide range of experimentally documented excitation patterns including current-distance and strength-duration relationships. Evaluation of different stimulus paradigms was performed using populations of fifty cells and fifty fibers of passage randomly positioned about an extracellular electrode(s). Monophasic cathodic or anodic stimuli enabled selective stimulation of fibers over cells or cells over fibers, respectively. However, when a symmetrical charge-balancing stimulus phase was incorporated, selectivity was greatly diminished. An anodic first, cathodic second asymmetrical biphasic stimulus enabled selective stimulation of fibers, while a cathodic first, anodic second asymmetrical biphasic stimulus enabled selective stimulation of cells. These novel waveforms provided enhanced selectivity while preserving charge balancing as is required to minimize the risk of electrode corrosion and tissue injury. Furthermore, the models developed in this study can predict the effectiveness of electrode geometries and stimulus parameters for selective activation of specific neuronal populations, and in turn represent useful tools for the design of electrodes and stimulus waveforms for use in CNS neural prosthetic devices.

Full Text

Duke Authors

Cited Authors

  • McIntyre, CC; Grill, WM

Published Date

  • March 2000

Published In

Volume / Issue

  • 28 / 3

Start / End Page

  • 219 - 233

PubMed ID

  • 10784087

Electronic International Standard Serial Number (EISSN)

  • 1573-9686

International Standard Serial Number (ISSN)

  • 0090-6964

Digital Object Identifier (DOI)

  • 10.1114/1.262


  • eng