The time course of attack priming effects in female golden hamsters

In two experiments using different procedures we have found that attack latency, having been reduced by a previous priming attack, returns to baseline levels over a 24 hr period. In both experiments an unexpected, transient increase in attack latency occured 2 hr postpriming. The procedure of the second experiment precludes the possibility that this is a circadian effect. There were no cumulative effects of successive priming attacks suggesting that, under the conditions of these experiments, each attack "resets" the animals' aggressive state. The effects of a single brief agonistic encounter are substantial and persistent enough to be involved in such phenomena as the escalation and redirection of aggression observed in field studies.