Self-Consistent Analyses For Potential Conduction Block In Nerves By An Ultra-Short, High-Intensity Electric Pulse

Summary form only given. Simulation studies are presented that probe the possibility of using high field (>100 kV/cm), short-duration (~50 ns) electrical pulses for a quick-acting, localized, and reversible cessation of biological electrical signaling pathways. This would have obvious applications in neurophysiology, clinical research, neuromuscular stimulation therapies, and neuro-muscular disruption leading to possible non-lethal bio-weapons. The concept of arresting action potential (AP) propagation on command through external electrical stimulation is based on creating a large density of pores on the membrane of axons. The advantages of such an approach include reversibility, suppression of possible self-launched action potentials, and negligible heating or tissue damage. A self-consistent theoretical analysis has been performed. The continuum approach based on the Smoluchowski equation was used to assess membrane electroporation by the high-intensity external pulse. Changes in membrane potential due to conduction current flows arising from localized electroporation were also considered. Our results indicate that a sufficiently high density of pores can be generated by a high-intensity, nanosecond electric pulse. The resulting change in membrane conductance then presents an effective "electrical short" to an incident voltage wave traveling across the nerve. The net effect is that the local membrane potential at the affected node is unable to rise significantly. This prevents current injection and activation of sodium channels downstream, thereby, blocking AP propagation. It has also been shown that poration at a single neural segment would be sufficient to produce an observable effect. In reality, more than one segment would be affected. Also, the influence of external electric fields would be better assessed by taking account of non-uniformities and spatial distributions of potential between nerves and the surface electrode regions.