Top: Experimental set up. Single pulses of TMS were applied to the hand area of the right primary motor cortex with an inter-pulse interval randomized between 6 and 10 s. Simultaneously, the neuronavigated coil position (yellow), electrocardiogram (red), respiratory signal (blue), electrogastrogram (green), and electromyography from the left hand (gray) were recorded. The figure shows traces of a 20-s time segment from one participant of the cardiac (raw), respiratory (filtered), gastric (filtered), and EMG (raw) signals. The experimental measure was the Motor Evoked Potential amplitude measured on a hand muscle (first dorsal interosseous), analyzed against the phase of the cardiac, respiratory, and gastric rhythms. Note that the three rhythms have very different periods (~1 s for the heart, ~ 5 s for respiration, and ~20 s for the gastric rhythm). Bottom: Artwork illustrating how rhythms of the internal organs interact with the moment-to-moment fluctuations observed in corticospinal motor excitability. Image depicts an outline of a brain with representations of the three rhythmic organs influencing the motor system: the heart, lungs, and stomach. Image credit: Tahnée Engelen.
How do internal bodily rhythms influence #brain activity & motor function? @tahnee-engelen.bsky.social &co show that #cardiac, #respiratory & #gastric rhythms independently modulate motor excitability, revealing distinct #interoceptive profiles across individuals @plosbiology.org 🧪 plos.io/4nMtpLT