Institut für Neurobiologie, Freie Universität Berlin, Königin-Luise-Str. 28-30, D-14195 Berlin, Germany.
Proc Biol Sci. 2011 Jun 22;278(1713):1873-80. doi: 10.1098/rspb.2010.2099. Epub 2010 Nov 24.
Aggression is a behavioural strategy for securing resources (food, mates and territory) and its expression is strongly influenced by their presence and value. While it is known that resource holders are generally highly aggressive towards intruding consexuals and usually defeat them, the underlying neuronal mechanisms are not known. In a novel intruder-resident paradigm for field crickets (Gryllus bimaculatus), we show that otherwise submissive losers of a preceding aggressive encounter readily fight and often defeat aggressive winners after occupying an artificial shelter. This aggression enhancing effect first became evident after 2 min residency, and was maximal after 15 min, but absent 15 min after shelter removal. The residency effect was abolished following non-selective depletion of biogenic amines from the central nervous system using reserpine, or semi-selective depletion of octopamine and dopamine using α-methyl-tyrosine, but not following serotonin depletion using α-methyl-tryptophan. The residency effect was also abolished by the treatment with phentolamine, an α-adrenergic receptor antagonist, or epinastine, a highly selective octopamine receptor blocker, but not by propranolol, a ß-adrenergic receptor antagonist, or by yohimbine, an insect tyramine receptor blocker. We conclude that crickets evaluate residency as a rewarding experience that promotes aggressive motivation via a mechanism involving octopamine, the invertebrate analogue of noradrenaline.
攻击性是一种获取资源（食物、配偶和领地）的行为策略，其表达受到资源的存在和价值的强烈影响。虽然已知资源占有者通常对入侵的同性别个体具有高度攻击性，并且通常会击败它们，但背后的神经元机制尚不清楚。在蟋蟀（Gryllus bimaculatus）的一种新颖的入侵者-居民范式中，我们表明，在先前的攻击性遭遇中处于劣势的温顺个体，一旦占据了人工庇护所，就会轻易地发起攻击，并且经常能够击败攻击性的获胜者。这种攻击性增强效应在居住 2 分钟后首次变得明显，在居住 15 分钟时达到最大值，但在庇护所移除 15 分钟后消失。使用利血平对中枢神经系统进行非选择性生物胺耗竭、使用α-甲基酪氨酸对章鱼胺和多巴胺进行半选择性耗竭，或使用α-甲基色氨酸对血清素进行耗竭，都会消除这种居住效应。使用苯肾上腺素（一种α-肾上腺素受体拮抗剂）或依普奈丁（一种高度选择性的章鱼胺受体阻断剂）处理也会消除这种居住效应，但使用心得安（一种β-肾上腺素受体拮抗剂）或育亨宾（一种昆虫酪胺受体阻断剂）处理则不会。我们得出结论，蟋蟀将居住评估为一种奖励性体验，通过一种涉及章鱼胺的机制促进攻击性动机，章鱼胺是去甲肾上腺素的无脊椎动物类似物。
