Transcranial electrical stimulation (tES – tDCS; tRNS, tACS) methods

Abstract

Weak transcranial direct current stimulation (tDCS) with a homogenous DC field at intensities of around 1 mA induces long-lasting changes in the brain. tDCS can be used to manipulate brain excitability via membrane polarisation: cathodal stimulation hyperpolarises, while anodal stimulation depolarises the resting membrane potential, whereby the induced after-effects depend on polarity, duration and intensity of the stimulation. A variety of other parameters influence tDCS effects; co-application of neuropharmacologically active drugs may most impressively prolong or even reverse stimulation effects. Transcranial alternating stimulation (tACS) and random noise stimulation (tRNS) are used to interfere with ongoing neuronal oscillations and also finally produce neuroplastic effects if applied with appropriate parameters.

Keywords:

• Transcranial direct current stimulation (tDCS)
• Transcranial alternating current stimulation (tACS)
• Transcranial random noise stimulation (tRNS)
• Transcranial magnetic stimulation (TMS)
• Rehabilitation
• Plasticity

Acknowledgments

I thank Jose´ Casadiego Bastidas for the calculations. Funded by the German Ministry of Education and Research, BMBF 01GQ0810 and the Rose Foundation.