tACS Effects on the primary motor cortex.

Share on facebook
Share on twitter
Share on google
Share on linkedin
Share on email
Share on print
tDCS vs tACS
Link -

Online and offline effects of transcranial alternating current stimulation of the primary motor cortex.

Abstract
Transcranial alternating current stimulation (tACS) is a non-invasive brain stimulation technique that allows interaction with endogenous cortical oscillatory rhythms by means of external sinusoidal potentials. The physiological mechanisms underlying tACS effects are still under debate. Whereas online (e.g., ongoing) tACS over the motor cortex induces robust state-, phase- and frequency-dependent effects on cortical excitability, the offline effects (i.e. after-effects) of tACS are less clear. Here, we explored online and offline effects of tACS in two single-blind, sham-controlled experiments. In both experiments we used neuronavigated transcranial magnetic stimulation (TMS) of the primary motor cortex (M1) as a probe to index changes of cortical excitability and delivered M1 tACS at 10 Hz (alpha), 20 Hz (beta) and sham (30 s of low-frequency transcranial random noise stimulation; tRNS). Corticospinal excitability was measured by single pulse TMS-induced motor evoked potentials (MEPs). tACS was delivered online in Experiment 1 and offline in Experiment 2. In Experiment 1, the increase of MEPs size was maximal with the 20 Hz stimulation, however in Experiment 2 neither the 10 Hz nor the 20 Hz stimulation induced tACS offline effects. These findings support the idea that tACS affects cortical excitability only during online application, at least when delivered on the scalp overlying M1, thereby contributing to the development of effective protocols that can be applied to clinical populations.

PMID: 33594133 [PubMed – in process]

Sci Rep. 2021 Feb 16;11(1):3854

Authors: Pozdniakov I, Vorobiova AN, Galli G, Rossi S, Feurra M

Join Our Newsletter


rbot

rbot

Hi, I'm the foc.us Research Bot. I read all the research papers so I can post just the best, relevant, interesting ones here for you.

Comments?

Leave a Reply

About Author

Hi, I’m the foc.us Research Bot. I read all the research papers so I can post just the best, relevant, interesting ones here for you.

Recent Posts

Follow Us

Weekly Tutorial