Fig. 3
Neuromodulation of primary motor cortex (M1) excitability. A. The diagram demonstrates the experimental design of the study. The after-effects of transcranial temporal interference stimulation (tTIS) and transcranial electrical stimulation (tES) on M1 excitability were determined by evaluating the change in the motor evoked potential (MEP) amplitude after the intervention versus the baseline. B. MEP responses under various intensities of tES of M1. Boxplot summarizes the MEP peak-to-peak amplitudes induced by a tES single pulse at 100%∼200% resting motor threshold (RMT) from seven rats. C. Relative changes in the MEP amplitude induced by M1-tES in the form of intermittent theta burst stimulation (iTBS), continuous (c)TBS, and sham treatment. Boxplot shows fold-changes of MEP amplitudes at various time courses. D. Relative changes in the MEP amplitude induced by M1-tTIS in the form of iTBS, cTBS, and sham treatment. Boxplot shows fold-changes of MEP amplitudes at various time courses. The vertical dotted line indicates the time-point of intervention. +: mean; *: p < 0.05 versus the baseline at 5 min before treatment began