Data from: Fighting experience alters brain androgen receptor expression dependent on testosterone status

Contest decisions are influenced by the outcomes of recent fights (winner–loser effects). Steroid hormones and serotonin are closely associated with aggression and therefore probably also play important roles in mediating winner–loser effects. In mangrove rivulus fish, Kryptolebias marmoratus, individuals with higher testosterone (T), 11-ketotestosterone and cortisol levels are more capable of winning, but titres of these hormones do not directly mediate winner–loser effects. In this study, we investigated the effects of winning/losing experiences on brain expression levels of the receptor genes for androgen (AR), oestrogen α/β (ERα/β), glucocorticoid (GR) and serotonin (5-HT1AR). The effect of contest experience on AR gene expression depended on T levels: repeated losses decreased, whereas repeated wins increased AR gene expression in individuals with low T but not in individuals with medium or high T levels. These results lend strong support for AR being involved in mediating winner–loser effects, which, in previous studies, were more detectable in individuals with lower T. Furthermore, the expression levels of ERα/β, 5-HT1AR and GR genes were higher in individuals that initiated contests against larger opponents than in those that did not. Overall, contest experience, underlying endocrine state and hormone and serotonin receptor expression patterns interacted to modulate contest decisions jointly.争斗决策会受近期打斗结果的影响（即胜-败效应）。类固醇激素与血清素和攻击行为密切相关，因此可能在介导胜-败效应中发挥重要作用。在红树林鳉（Kryptolebias marmoratus）中，睾酮（T）、11-酮睾酮及皮质醇水平更高的个体获胜能力更强，但这些激素的滴度并未直接介导胜-败效应。本研究探究了胜/负经历对雄激素受体（AR）、雌激素α/β受体（ERα/β）、糖皮质激素受体（GR）及血清素（5-HT1AR）相关基因在脑部表达水平的影响。争斗经历对AR基因表达的影响依赖于T水平：在T水平较低的个体中，反复失败会降低AR基因表达，而反复获胜则会升高其表达，但该效应在T水平中等或较高的个体中未出现。上述结果有力支持了AR参与介导胜-败效应的结论，此前相关研究中，胜-败效应在T水平较低的个体中更易被检测到。此外，相较于未发起对战较大体型对手的个体，发起此类对战的个体其ERα/β、5-HT1AR及GR基因的表达水平更高。总体而言，争斗经历、内在内分泌状态，以及激素与血清素受体的表达模式三者相互作用，共同调控争斗决策。