Social experience and the establishment of behavioural syndromes - novel insights from crickets into the role of serotonin in aggression, “personality” and depression-like phenomena

最近，人们认识到，同一物种的单个动物，包括许多无脊椎动物，在行为上表现出一致的差异(通常被称为动物个性)。然而，人们对这种个体间行为差异是如何产生的知之甚少。我们最近发表的关于雄性蟋蟀的初步研究表明，社会经验起着决定性的作用。就像许多动物一样，战胜同种蟋蟀的蟋蟀会变得极端攻击性，而输掉比赛的蟋蟀会变得顺从，但这些变化是短暂的(20分钟和3小时)。然而，与哺乳动物一样，多重失败(长期的社会失败)也会导致对蟋蟀攻击性的长期抑制(24小时，可能是终生的)。此外，赢和输的经历会导致一般运动、探索行为和对触觉刺激的运动反应的长期变化。我们已经在几篇论文中表明，获胜者的过度攻击性是由胺章鱼胺介导的，失败者的抑郁是由一氧化氮信号通路的激活引起的。我们现在的目标是研究这些神经调节剂在决定攻击性经历导致的行为长期变化中的作用。https://de.wiktionary.org/wiki/submissiv。初步研究表明，慢性社会挫败会导致长期的攻击性抑郁，并通过一氧化氮和5-羟色胺的共同作用产生抑郁的探索行为。这是对5-羟色胺在攻击性中的自然行为作用的罕见洞察，目前无脊椎动物或哺乳动物还不了解这一点。在包括人类在内的哺乳动物中，慢性社交失败是导致抑郁症等症状的主要应激源，但其潜在的直接机制尚不清楚。因此，我们的工作不仅有可能在无脊椎动物模型中揭示出一种由神经调节剂介导的经验依赖性可塑性的形式，而且还可能为5-羟色胺在类抑郁现象中的作用提供新的见解。

Recently it has become recognised that individual animals of the same species, including many invertebrates, show consistent difference in their behaviour (often referred to as animal personality). Little is known, however, how such inter-individual behavioural differences arise. Our recently published and preliminary work on male crickets reveals that social experience plays a decisive role. As in many animals, crickets that win a fight against a conspecific become hyper-aggressive, while those that lose become submissive, but these changes are short lived (20 min and 3 h). However, as in mammals, multiple defeats (chronic social defeat) also lead to longer term suppression of aggression in crickets (>24 h, possibly life-long). Moreover, the winning and losing experiences lead to long-term changes in general motility, exploratory behaviour and the motor response to tactile stimulation. We have already shown in several papers that the hyper-aggressiveness of winners is mediated by the amine octopamine, and that loser depression results from activation of the nitric oxide signalling pathway. We now aim to investigate t https://de.wiktionary.org/wiki/submissiv he role of such neuromodulators in determining long term changes in behaviour resulting from aggressive experience. Preliminary work indicates that chronic social defeat induces long term depression of aggression coupled with depressed exploratory behaviour via the combined action of nitric oxide and serotonin. This is a rare insight into the natural behavioural role of serotonin in aggression, which is currently not understood in invertebrates or mammals. In mammals, including humans, chronic social defeat is a major stressor that induces depression like symptoms, but the underlying proximate mechanisms are unclear. Thus, our work not only has the potential to unveil “personality” in a model invertebrate as a form of experience dependent plasticity mediated by neuromodulators, it may also offer novel insights into the role of serotonin in depression-like phenomena.