Acute cholecystokinin effects on event-related potentials in healthy volunteers.

This study investigated the effects of a continuous slow infusion of cholecystokinin tetrapeptide (CCK-4), a neuropeptide with panicogenic properties, on brain event-related potentials (ERPs) in healthy adults. Twenty-four volunteers, 15 females and 9 males, were assigned to infusion with either placebo or CCK-4 in a randomized, double-blind, parallel group design. ERPs, elicited within a standard auditory odd-ball paradigm requiring the counting of rare (20%) occurring 'deviant' tones interspersed among more frequent (80%) occurring 'standard' tones, were assessed once before infusion, and at 10 min and 40 min after the onset of infusion. Compared with the placebo, CCK-4 delayed the latencies of N100 and P200 components elicited by 'deviant' stimuli. No significant treatment differences were observed with respect to N200, P300b, mood or adverse symptoms. These preliminary findings suggest that CCK-4 may interfere with information processing relating to the selection of significant stimuli and as such, may be of relevance to mechanisms underlying panic disorder.