Tyraminergic modulation of agonistic outcomes in crayfish
Tyraminergic modulation of agonistic outcomes in crayfish
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DOI：
10.1007/s00359-018-1255-3
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发表时间：
2018-02
期刊：
影响因子：
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通讯作者：
Yuto Momohara;H. Aonuma;T. Nagayama
中科院分区：
文献类型：
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作者：
Yuto Momohara;H. Aonuma;T. Nagayama
章鱼胺是一种生物胺，调节各种行为，从运动和攻击到无脊椎动物的学习和记忆。最近的几项研究表明，酪胺，章鱼胺的生物前体，也会影响章鱼胺之外的行为。本文研究了酪胺在克氏原螯虾雄虾间拮抗相互作用中的作用。当雄性小龙虾打架时，体型较大的动物（体长差异为3-7%）更有可能获胜。相比之下，直接注射酪胺或章鱼胺会抵消大型动物的身体优势。注射酪胺或章鱼胺的幼年大动物大多被未治疗的幼年小动物殴打。这种药理作用类似于失败者效应，即从属的大型动物经常被较小的动物打败。此外，注射epinastine（一种章鱼胺阻滞剂）或育亨宾（一种酪胺阻滞剂）可以部分消除loser效应，注射两种阻滞剂的混合物可以显著减少loser效应。我们还观察到，在输掉战斗后，下属小龙虾食道下神经节中的酪胺水平显著增加。这些结果表明酪胺可以调节小龙虾的攻击性水平，并与章鱼胺一起产生失败者效应。
Octopamine, a biogenic amine, modulates various behaviors, ranging from locomotion and aggression to learning and memory in invertebrates. Several studies recently demonstrated that tyramine, the biological precursor of octopamine, also affects behaviors independent of octopamine. Here we investigated the involvement of tyramine in agonistic interaction of the male crayfishProcambarus clarkii. When male crayfish fight, larger animals (3–7% difference in body length) are more likely to win. By contrast, direct injection of tyramine or octopamine counteracted the physical advantage of larger animals. Tyramine or octopamine-injected naive large animals were mostly beaten by untreated smaller naive animals. This pharmacological effect was similar to the loser effect in which subordinate larger animals are frequently beaten by smaller animals. Furthermore, loser effects were partly eliminated by either injection of epinastine, an octopamine blocker, or yohimbine, a tyramine blocker, and significantly diminished by injection of a mixture of both blockers. We also observed that tyramine levels in the subesophageal ganglion were remarkably increased in subordinate crayfish after losing a fight. These results suggest that tyramine modulates aggressive levels of crayfish and contributes to the loser effect in parallel with octopamine.