REVERSED BEHAVIORAL-EFFECT OF CHOLECYSTOKININ AFTER FRONTAL DECORTICATION IN RATS

Cholecystokinin tetrapeptide (CCK-4) is likely to posses opposite cent ral action against cholecystokinin octapeptide (CCK-8). In the present study, the behavioral effects of CCK-4 and CCK-8 were compared in fro ntal decorticated rats. In sham-operated rats, CCK-4 produced marked e xcitatory responses, while CCK-8 had no stimulatory effects. In fronta l decorticated rats, CCK-LC did not cause any excitatory behaviors, wh ile CCK-8 produced markedly enhanced responses. We speculate that an a ppropriate balance of these CCK peptides might be involved in the main tenance of normal mental states.