FIGURE 2.

Changes in biceps brachii cervicomedullary motor evoked potential (CMEP) amplitude after placebo (PLA) and cyproheptadine (CYP) administration. (a) Waveform averages of biceps CMEPs are shown for a single participant before (baseline) and after (post‐pill) administration of placebo (top panel) and cyproheptadine (bottom panel). Baseline traces are the average of 15 CMEPs and post‐pill traces are the average of 25 CMEPs. Dotted horizontal traces denote the maximum and minimum waveform responses at baseline for each drug condition. (b) Post‐pill CMEP amplitudes are shown for the group (mean ± SD, n = 9). Individual values for each participant are also shown. CMEP amplitudes were first normalised to the amplitude of the maximal compound muscle action potential (M_max), and then normalised to baseline CMEP (% of M_max) values. (c) Individual post‐pill CMEP amplitudes are shown for the cyproheptadine condition, where cyproheptadine amplitudes are presented as a difference from post‐pill placebo values to show the direction of change for each participant after drug intake (cyproheptadine minus placebo)