tACS entrains neural activity while somatosensory input is blocked.

Share on facebook
Share on twitter
Share on google
Share on linkedin
Share on email
Share on print
Macaques
Link -

tACS entrains neural activity while somatosensory input is blocked.

Abstract
Transcranial alternating current stimulation (tACS) modulates brain activity by passing electrical current through electrodes that are attached to the scalp. Because it is safe and noninvasive, tACS holds great promise as a tool for basic research and clinical treatment. However, little is known about how tACS ultimately influences neural activity. One hypothesis is that tACS affects neural responses directly, by producing electrical fields that interact with the brain’s endogenous electrical activity. By controlling the shape and location of these electric fields, one could target brain regions associated with particular behaviors or symptoms. However, an alternative hypothesis is that tACS affects neural activity indirectly, via peripheral sensory afferents. In particular, it has often been hypothesized that tACS acts on sensory fibers in the skin, which in turn provide rhythmic input to central neurons. In this case, there would be little possibility of targeted brain stimulation, as the regions modulated by tACS would depend entirely on the somatosensory pathways originating in the skin around the stimulating electrodes. Here, we directly test these competing hypotheses by recording single-unit activity in the hippocampus and visual cortex of alert monkeys receiving tACS. We find that tACS entrains neuronal activity in both regions, so that cells fire synchronously with the stimulation. Blocking somatosensory input with a topical anesthetic does not significantly alter these neural entrainment effects. These data are therefore consistent with the direct stimulation hypothesis and suggest that peripheral somatosensory stimulation is not required for tACS to entrain neurons.

PMID: 33001971 [PubMed – as supplied by publisher]

PLoS Biol. 2020 Oct 01;18(10):e3000834

Authors: Vieira PG, Krause MR, Pack CC

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