Pulsatile electrical stimulation creates predictable, correctable disruptions in neural firing

Abstract

Electrical stimulation of neural responses is used both scientifically in brain mapping studies and in many clinical applications such as cochlear, vestibular, and retinal implants. Due to safety considerations, stimulation of the nervous system is restricted to short biphasic pulses. Despite decades of research and development, neural implants are far from optimal in their ability to restore function and lead to varying improvements in patients. In this study, we provide an explanation for how pulsatile stimulation affects individual neurons and therefore leads to variability in restoration of neural responses. The explanation is grounded in the physiological response of channels in the axon and represented with mathematical rules that predict firing rate as a function of pulse rate, pulse amplitude, and spontaneous activity. We validate these rules by showing that they predict recorded vestibular afferent responses in macaques and discuss their implications for designing clinical stimulation paradigms and electrical stimulation-based experiments.

Galvanic vs. pulsatile effects on decision-making networks: reshaping the neural activation landscape

“…To compare PS to GS in this study we specifically chose PS train parameters to mimic the stimulation paradigm of the previous experiments [34]. Previously published experimental work as well as our own computational analysis suggests that varying pulse rate has strong nonlinear effects on the resulting firing rate of targeted neurons especially for high amplitude pulses and in the presence of spontaneous activity [28][29][30]. Indeed, in this publication we see this effect with the inhibition of the neurons closest to the electrode that experience the highest amplitude.…”

“…In further examination of the previously observed neural responses to PS [28], our recent work [29,30], using an adapted axon model from Hight and Kalluri [31], systematically catalogues the possible firing rate responses to biphasic PS trains. For example, pulses can block the spontaneous APs, spontaneous APs can block subsequent pulses, and pulses can block subsequent pulses.…”