Figure 3
Interhemispheric inhibition (IHI) from the M1 hand area contralateral (M1 contra-H ) to that ipsilateral (M1 ipsi-H ) to the fatigued lower limb. (a) IHI from the M1contra-H to M1ipsi-H (10 min) recorded from the first dorsal interosseous muscle of a representative subject before (PRE, left column), immediately after (POST1, middle column), and 10 min after (POST2, right column) fatiguing unilateral plantar flexions. Solid lines are single-pulse motor evoked potentials (MEPs) elicited by adjusted test stimulus (TS) intensity; gray lines are single-pulse MEPs elicited by non-adjusted TS intensity; and dashed lines are conditioned MEPs. Arrows indicate the time points at the TS and conditioning stimulus (CS) are delivered. Ten traces were average in each set. Note that the adjusted TS intensities (% of maximal stimulator output (MSO)) decreased with time. (b) Group data (n = 10). The abscissa shows time points of measurements (PRE, POST1, and POST2). The ordinate shows the magnitude of IHI, in which the size of the conditioned MEPs is expressed as a percentage of the size of the adjusted single-pulse MEPs. #indicates statistical significance from PRE (p < 0.05). Error bars indicate SD.