THE EFFECTS OF RECEPTOR BLOCKERS ON ATRIAL NATRIURETIC PEPTIDE-INDUCED ACTION ON PASSIVE-AVOIDANCE BEHAVIOR IN RATS

In previous experiments, it was shown that rat atrial natriuretic peptide (rANP1-28) is able to increase the passive avoidance latency in a dose-dependent manner in the learning and consolidation phase (3). In order to clarify whether ANP has a direct action on this behavioral paradigm, or whether the action is mediated by neurotransmitters, rats were pretreated with different receptor blockers. The selected doses of the different receptor blockers could themselves not influence the behavioral paradigms. Haloperidol or atropine blocked the action of ANP on the consolidation of the passive avoidance response. Phenoxybenzamine, propranolol, methysergide, bicuculline and naloxone were ineffective. The data suggest that dopaminergic and cholinergic mediations are involved in the action of ANP on the passive avoidance response.