Haller J, Makara G B, Kruk M R
Institute of Experimental Medicine, Hungarian Academy of Sciences, Budapest.
Neurosci Biobehav Rev. 1998;22(1):85-97. doi: 10.1016/s0149-7634(97)00023-7.
Noradrenaline is involved in many different functions, which all are known to affect behaviour profoundly. In the present review we argue that noradrenaline affects aggression on three different levels: the hormonal level, the sympathetic autonomous nervous system, and the central nervous system (CNS), in different, but functionally synergistic ways. Part of these effects may arise in indirect ways that are by no means specific to aggressive behaviour, however, they are functionally relevant to it. Other effects may affect brain mechanisms specifically involved in aggression. Hormonal catecholamines (adrenaline and noradrenaline) appear to be involved in metabolic preparations for the prospective fight; the sympathetic system ensures appropriate cardiovascular reaction, while the CNS noradrenergic system prepares the animal for the prospective fight. Indirect CNS effects include: the shift of attention towards socially relevant stimuli; the enhancement of olfaction (a major source of information in rodents); the decrease in pain sensitivity; and the enhancement of memory (an aggressive encounter is very relevant for the future of the animal). Concerning more aggression-specific effects one may notice that a slight activation of the central noradrenergic system stimulates aggression, while a strong activation decreases fight readiness. This biphasic effect may allow the animal to engage or to avoid the conflict, depending on the strength of social challenge. A hypothesis is presented regarding the relevance of different adrenoceptors in controlling aggression. It appears that neurons bearing postsynaptic alpha2-adrenoceptors are responsible for the start and maintenance of aggression, while a situation-dependent fine-tuning is realised through neurons equipped with beta-adrenoceptors. The latter phenomenon may be dependent on a noradrenaline-induced corticosterone secretion. It appears that by activating very different mechanisms the systems working with adrenaline and/or noradrenaline prepare the animal in a very complex way to answer the demands imposed by, and to endure the effects caused by, fights. It is a challenge for future research to elucidate how precisely these mechanisms interact to contribute to functionally relevant and adaptive aggressive behaviour.
去甲肾上腺素参与多种不同功能，所有这些功能都已知会对行为产生深远影响。在本综述中，我们认为去甲肾上腺素以不同但功能协同的方式在三个不同水平上影响攻击行为：激素水平、交感自主神经系统和中枢神经系统（CNS）。然而，这些影响的一部分可能以并非特定于攻击行为的间接方式出现，但它们在功能上与之相关。其他影响可能会影响专门参与攻击行为的脑机制。激素儿茶酚胺（肾上腺素和去甲肾上腺素）似乎参与了对预期战斗的代谢准备；交感神经系统确保适当的心血管反应，而中枢神经系统去甲肾上腺素能系统使动物为预期战斗做好准备。中枢神经系统的间接影响包括：注意力转向与社交相关的刺激；嗅觉增强（啮齿动物的主要信息来源）；疼痛敏感性降低；以及记忆力增强（一次攻击性遭遇对动物的未来非常重要）。关于更具攻击性的特定影响，可以注意到中枢去甲肾上腺素能系统的轻微激活会刺激攻击行为，而强烈激活则会降低战斗准备状态。这种双相效应可能使动物根据社会挑战的强度参与或避免冲突。提出了一个关于不同肾上腺素能受体在控制攻击行为中的相关性的假设。似乎带有突触后α2-肾上腺素能受体的神经元负责攻击行为的启动和维持，而通过配备β-肾上腺素能受体的神经元实现依赖于情况的微调。后一种现象可能依赖于去甲肾上腺素诱导的皮质酮分泌。似乎通过激活非常不同的机制，与肾上腺素和/或去甲肾上腺素一起工作的系统以非常复杂的方式使动物做好准备，以应对战斗带来的需求并承受战斗造成的影响。阐明这些机制如何精确相互作用以促成功能相关且适应性的攻击行为是未来研究的一个挑战。
