Inducing LTD-Like Effect in the Human Motor Cortex with Low Frequency and Very Short Duration Paired Associative Stimulation: An Exploratory Study

Figure 3

Original MEP amplitude and normalized MEP amplitudes of 11 subjects with 95% confidence interval of 1-minute stimulation of 0.25 Hz . The original MEP amplitudes are reported as a median with 95% confidence interval (a). One-way repeated-measures ANOVA showed a significant LTD-like effect in 11 subjects (reported as an uncorrected value) ( value < 0.05). Post hoc analysis showed that the inhibitory effect began immediately after applied (T1), 15 (T15), 20 (T20), 25 (T25), and 30 minutes (T30) ( value < 0.05). The maximum inhibition was approximately 55% reduction (b). Min = minute, MEP = motor-evoked potentials, LTD = long-term depression, and = paired associative stimulation with interstimulus interval of 10 ms.

(a)  

(b)