Asymmetric Neurogenomic States Emerge in Winners and Losers After Social Competition

Abstract

Winner and loser effects can influence future aggressive behavior following social competition, but their neurogenomic basis remains poorly understood. Using Betta splendens, we integrated behavioral analyses, whole-brain RNA sequencing, and genomic coexpression network analyses to investigate how social experiences influence enduring behavioral and molecular states. Winners showed increased attack frequency, whereas losers prolonged aggressive latency, indicating effects on distinct behavioral aspects. Winners and losers initially shared acute responses in terms of both gene expression and network coordination but subsequently diverged through outcome-specific patterns of network reorganization, despite few persistent differentially expressed genes. This divergence was asymmetric and involved multiple components: immune-related networks showed notable contrasts, with winners displaying anticipated postconflict coordination but losers instead showing discoordination, whereas neuroendocrine and purinergic networks diverged over distinct temporal scales. These findings highlight transcriptomic network-level remodeling as a potential key feature of the winner-loser effect.