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bioRxiv · 10.1101/2022.07.06.499054

A minimum effective dose for (transcranial) alternating current stimulation

Alekseichuk, I.·Wischnewski, M.·Opitz, A.
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Abstract

Transcranial alternating current stimulation (tACS) is a popular method for non-invasive neuromodulation in human research and therapy. However, what constitutes an effective dose in tACS applications is still a matter of investigation and debate. Here, we examined available literature data regarding the effects of alternating current (AC)-induced electric fields on cellular-level neural activity. The literature search identified 16 relevant experimental reports that utilized brain slices, anesthetized rodents, and awake/behaving animal models. We implemented a probabilistic meta-analysis to estimate the minimum effective dose (MED) required for inducing detectable significant neural changes with AC stimulation. The results showed that AC stimulation at 0.3 mV/mm in awake/behaving mammals leads to an 80% probability of inducing minimum neural effects. A similar level of effectiveness in brain slices and anesthetized mammals required 0.7 mV/mm. In conclusion, (transcranial) alternating current stimulation is significantly more effective in awake than in anesthetized brains. The proposed dose targets can serve as a practical guideline for tACS in humans.

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Alekseichuk, I., Wischnewski, M., Opitz, A.. 2022-07-07. A minimum effective dose for (transcranial) alternating current stimulation. https://doi.org/10.1101/2022.07.06.499054

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