Damage-free peripheral nerve stimulation by 12-ns pulsed electric field

Area of Science:

• Biophysics
• Neuroscience
• Biomedical Engineering

Background:

• Modern technologies allow for deep tissue stimulation using nanosecond pulsed electric fields (nsPEF).
• The ability of nsPEF, with durations shorter than voltage-gated sodium channel (VGSC) activation times, to evoke action potentials (APs) remains largely unexplored.
• Electroporation and subsequent depolarization were previously considered necessary intermediate steps for PEF-induced excitation.

Purpose of the Study:

• To investigate whether 12-nanosecond pulsed electric fields (nsPEF) can excite peripheral nerves without causing electroporation.
• To compare the efficacy and safety of nsPEF stimulation with conventional nerve stimulation methods.
• To determine the impact of nsPEF on nerve fiber selectivity and refractory properties.

Main Methods:

• Peripheral nerves were stimulated using 12-ns nsPEF at high electric field strengths (3.3-8.8 kV/cm).
• Stimulation parameters included varying intensities and frequencies (50 Hz, 100 Hz) for tetanic stimulation.
• Action potentials (APs) and nerve refractory properties were monitored, and comparisons were made with conventional long-pulse stimulation (100-250 μs).

Main Results:

• 12-ns nsPEF successfully evoked APs in peripheral nerves without inducing electroporation.
• nsPEF exhibited higher selectivity for faster nerve fibers compared to conventional stimuli.
• Repeated tetanic stimulation with nsPEF resulted in a modest decrease in APs, comparable to conventional stimuli, with no observed cumulative damage after tens of thousands of pulses.
• Nerve refractory properties remained unaffected by nsPEF stimulation.

Conclusions:

• VGSC activation by nsPEF is possible without causing nerve membrane damage or electroporation.
• 12-ns nsPEF represents a viable, non-invasive method for nerve stimulation with potential for selective targeting of nerve fibers.
• nsPEF stimulation shows promise for therapeutic applications due to its efficacy and lack of cumulative damage.