A Discussion of tACS Literature
Driving human motor cortical oscillations leads to behaviorally relevant changes in local GABAa inhibition: A tACS-TMS study.
Nowak, Magdalena, Emily Hinson, Freek van Ede, Alek Pogosyan, Andrea Guerra, Andrew Quinn, Peter Brown, & Charlotte J. Stagg. (2017) Driving human motor cortical oscillations leads to behaviorally relevant changes in local GABAa inhibition: A tACS-TMS study. J Neurosci. 37(17): 4481-4492.
Summary: Nowak and colleagues conducted a study to investigate the effects of GABA-A receptor mediated inhibition on beta- and gamma-band tACS effects in the motor cortex. Using ppTMS before, during, and after 20 minutes of individualized beta and 75 Hz (gamma) tACS and a sham condition, the researchers identified a transient decrease in SICI (less inhibition) during the first 5 minutes of 75 Hz tACS, which shifted towards increased inhibition by the end of the stimulation period (15 min). The early transient reduction in SICI strongly correlated with motor learning tested during a serial reaction time task completed prior to the stimulation sessions. These findings suggest gamma-band tACS engages GABAergic systems in the motor cortex with duration dependent effects, and that the responsiveness of the GABAergic system is predictive of individual motor learning capabilities.
Contributed by: Christopher Walker, PhD
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Every week, there are new and exciting scientific papers published on studies that investigated tACS. Reading and understanding these papers unfortunately requires both access to (sometimes quite expensive) scientific journals and in-depth "insider knowledge." Our goal is to share with you brief summaries of tACS studies that give you a big-picture idea of what the publications are about. There are too many studies to feature all of them but we will continuously update this page. If you have a specific study you would like to get featured, please contact us. The contributors are personnel from the Frohlich Lab and the Carolina Center for Neurostimulation.