Electrical stimulation of neuronal tissue is a promising strategy to treat a variety of neurological disorders. The mechanism of neuronal activation by external electrical stimulation is governed by voltage-gated ion channels. This stimulus, typically brief in nature, leads to membrane potential depolarization, which increases ion flow across the membrane by increasing the open probability of these voltage-gated channels. In spiking neurons, it is activation of voltage-gated sodium channels (NaV-channels) that leads to action potential generation. However, several other types of voltage-gated channels are expressed, that also respond to electrical stimulation. In this study, we examine the response of voltage-gated potassium channels (KV-channels) to brief electrical stimulation by whole-cell patch clamp electrophysiology and computational modelling. We show that non-spiking amacrine neurons of the retina exhibit a large variety of responses to stimulation, driven by different KV-channel subtypes. Computational modelling reveals substantial differences in the response of specific KV-channel subtypes that is dependent on channel kinetics. This suggests that the expression levels of different KV-channel subtypes in retinal neurons are a crucial predictor of the response that can be obtained. These data expand our knowledge of the mechanisms of neuronal stimulation and suggest that KV-channel expression is an important determinant of the sensitivity of neurons to electrical stimulation.
- electrical stimulation
- potassium channels
- Copyright © 2016, Journal of Neurophysiology