Transcranial electrical stimulation (tES) mechanisms and its effects on cortical excitability and connectivity

Abstract

In this review, we describe transcranial electrical stimulation (tES) techniques currently being used in neuroscientific research, including transcranial direct current (tDCS), alternating current (tACS) and random noise (tRNS) stimulation techniques. We explain how these techniques are used and summarise the proposed mechanisms of action for each technique. We continue by describing how each method has been used to alter endogenous neuronal oscillations and connectivity between brain regions, and we conclude by highlighting the varying effects of stimulation and discussing the future direction of these stimulation techniques in research.

Non-invasive Brain Stimulation for the Treatment of Gilles de la Tourette Syndrome

“…In contrast to TMS, transcranial electrical current stimulation does not cause action potentials directly (39). It rather modulates neuronal transmembrane potentials increasing neural excitability at the anodal electrode and decreasing it at the cathodal electrode (40).…”

“…It rather modulates neuronal transmembrane potentials increasing neural excitability at the anodal electrode and decreasing it at the cathodal electrode ( 40 ). Transcranial electrical current induced activation is thought to be mediated by decreased γ-aminobutyric acid (GABA) concentrations ( 41 ) as well as increased brain-derived neurotrophic factor ( 39 ), and glutamate and glutamine concentrations ( 42 ).…”

Prospects for transcranial temporal interference stimulation in humans: a computational study

“…Transcranial current stimulation (tCS) entails sending weak (≤ 2 mA) currents through the brain via electrodes placed on the scalp (see Reed and Cohen Kadosh, 2018, for a review). Applying direct current (tDCS) has been shown to affect the excitability of stimulated neurons (Nitsche and Paulus, 2000;Dissanayaka et al, 2017), while alternating currents (tACS) can also synchronize neuronal spikes and entrain them to the stimulation frequency (Zaehle et al, 2010;Tavakoli and Yun, 2017).…”

Effects of Transcranial Electrical Stimulation on Human Auditory Processing and Behavior—A Review

“…Transcranial electrical stimulation (tES) is a non-invasive brain stimulation method that uses a low-intensity electrical current to stimulate the target area of the cerebral cortex [ 3 ], regulates the excitability of cerebral cortex neurons and the brain wave rhythm [ 4 ], and promotes nerve remodeling and repair [ 5 ]. TES mainly includes transcranial direct current stimulation (tDCS), transcranial alternating current stimulation (tACS), and transcranial random noise stimulation (tRNS) [ 6 ].…”