Figure 3.

Nicotinergic impact on paired associative stimulation (PAS)-induced neuroplasticity. The graphs show baseline-standardized motor-evoked potential (MEP) amplitudes on the Y axis plotted at different time points following the stimulation. (a) In the placebo condition (squares), PAS-25 induced a clear increase of MEP amplitudes lasting for 90 min after stimulation. With nicotine (circles), the facilitatory after-effect of PAS-25 is slightly prolonged. (b) PAS-10 under placebo medication (squares) induced a prominent decrease of MEP amplitudes significantly until 90 min after stimulation. Nicotine (circles) abolished the inhibitory after-effect of PAS-10. Filled symbols indicate statistically significant deviations from baseline and asterisks indicate significant differences between the control and nicotine conditions (Student's t-test, paired, two-tailed, p<0.05). SE, same evening; NM, next morning; NE, next evening. Error bars indicate standard error of mean.