Time course of intranasally administered cholecystokinin-8 on central nervous effects

The gut and brain peptide cholecystokinin (CCK) exerts a number of central nervous effects. Among them are effects on attention and stimulus processin g as revealed by modulations of event-related potentials (ERPs), In the pre sent study the time course of central nervous effects after an intranasal a dministration of CCK-8 was investigated by means of ERPs, ERPs were recorde d in an odd ball paradigm 15, 30, 60, 90, 120, and 240 min after administra tion. Following the double-blind intranasal administration of CCK-8 and pla cebo, the late positive complex (LPC) of the E R P was significantly increa sed following CCK-8 compared to placebo. This effect was more pronounced in women than in men. The enhancement of the LPC by intranasal CCK-8 was not restricted to a specific recording time but reached its maximum 120 min aft er administration in men and women. Moreover, results tentatively indicate that 30 min after administration of CCK-8 the LPC increased only in women b ut not in men. The early effect of intranasal CCK-8 on LPC in women is unli kely to be caused by changes in plasma CCK-8 levels and suggests a direct n ose-brain pathway. Copyright (C) 2001 S.Kaiger AG, Basel.