Accelerating Neurite Outgrowth Through Electric Field Manipulation

Abstract

Brief electrical stimulation accelerates neuronal regeneration both in individual cells and in living models. In vitro experiments facilitate further understanding of regeneration mechanisms, and are typically carried out by plating individual cells on slides or microelectrode arrays. However, uniform electric fields may be better suited to enhance growth than traditionally used point-source fields. Applied uniform electric fields would allow for long distance stimulation with-out requiring destructively high voltages, and may be more easily transferred to an implantable design for clinical use. The viability of uniform electric field stimulation was explored in this study through the use of a custom-fabricated planar microelectrode array. Simulation of several electrode configurations resulted in the design of a parallel plate anode-cathode pair. Several such electrode pairs were embedded onto a single microelectrode array at various gap widths, to allow for the study of electric field strength on overall growth. With this novel electrode array, individual Lymnaea snail cells were stimulated with a 20 Hz, 1 volt pulse train for one hour. The impact of this stimulation on growth was measured 24 hours later, and compared to control cells plated on identical electrode arrays that were not stimulated. Stimulated cells showed an increase in overall neurite length compared to the control group. This effect was seen regardless of stimulus magnitude, within the range of 1000 - 2000 mV/mm.