Saccadic peak velocity and EEG as end-points for a serotonergic challenge test

We previously reported that a single dose of the serotonin receptor agonist meta‐chlorophenylpiperazine increased the peak velocity of saccadic eye movements and decreased low‐frequency electroencephalographic activity. Methods We administered a single dose of the serotonin releaser dexfenfluramine in a double blind, placebo controlled randomised cross‐over design and measured saccadic eye movements and EEG every hour up to 6 h. Subjects were 62 males (18–30 years) with a history of no, moderate or heavy use of ecstasy tablets. Results Dexfenfluramine increased saccadic peak velocity and decreased alpha, delta and theta electroencephalographic activity, the latter predominantly in heavy users of ecstasy. Conclusions This study supports the idea that saccadic peak velocity and EEG can be useful endpoints of a serotonergic challenge. This could be an important anatomical extension of these end‐points, which until now were limited to the effect on hypothalamic serotonergic projections. Copyright © 2002 John Wiley & Sons, Ltd.