Learning and memory consolidation in aggression behavior

Abstract

Aggressive behavior is important for animals for survival and reproduction as it helps in getting access to necessities like food and mates. Therefore aggressive behavior can be considered as an indicative of fitness of an organism. Such behavior can be effectively studied in Drosophila melanogaster, where flies put into a chamber demonstrate specific fighting strategies against opponents and forms clear dominance relationships. Moreover flies tend to learn and remember these fighting strategies over some time. Thus this paradigm offers an excellent opportunity to study short or mid-term memory in Drosophila. During tests we put two flies into a chamber for first fight, removed and returned to their respective vials and then reintroduce them against different opponent for their second fight. We found that in Canton-S flies, winner and loser flies tend to progressively learn lunging and retreating respectively. Moreover loser flies tend to lose their subsequent fights while winner flies fought with equal probability of winning/losing. This suggests a role of loser mentality in these outcomes. We then did these experiments on memory mutants of amnesiac and rutabaga gene. Winner and loser amnesiac mutant flies progressively learnt lunging and retreating during a fight but failed to emulate these strategies in their subsequent fights. On the other hand rutabaga mutant flies failed to learn any fighting strategies during trials which then resulted in lack of dominance relationships. Our results for the first time demonstrate prominent role for rutabaga gene in short term learning and amnesiac gene in consolidation of memories formed in context of agonistic interactions between flies.