| Abstract: | The effect of novel potent CCK-8 antagonists on a one-trial passive avoidance response was investigated in the rat. Intracerebroventricular administration of L-364,718 and CR 1409 in doses of 10 ng per rat or more and proglumide in doses of 100 ng per rat or more completely attenuated the passive avoidance response, when examined 24 hr after the injection. The effective doses of these antagonists did not cause any motility change, as tested by an open-field situation at the same period of time after the central administration. The present findings, together with our previous results on an active avoidance response, suggests that endogenous CCK-8 may be involved in memory processes. |
