Aggression and Amines: The Roles of Serotonin and Octopamine Neurons

在包括人类在内的许多物种中，血清素都与攻击性有关。在脊椎动物中，低水平的这种胺，可能加上高水平的去甲肾上腺素，与一种特殊的冲动暴力有关。虽然这项研究引起了极大的兴趣，但在脊椎动物系统中，由于涉及大量神经元元素，很难在单个神经元水平上将胺和攻击联系起来，以及神经系统中伴随暴力行为发生的精确变化。在无脊椎动物系统中，由于其可识别的大型神经元数量有限，对复杂行为过程（如攻击）的分析可以提升到被认为对行为至关重要的精确细胞的水平。这个应用程序继续我们的研究，探索从龙虾中枢神经系统（cns）中识别的单个神经细胞的功能，这些细胞含有并利用胺5 -羟色胺和章鱼胺（无脊椎动物相当于去甲肾上腺素）。我们认为，这两种胺至少在龙虾对抗（战斗）行为中重要的姿势成分上具有相反的作用。血清素细胞是我们研究的重点，是神经分泌细胞。这些细胞在两个地方释放血清素：(i)在中枢神经系统内，在那里它影响与姿势和逃逸有关的通路；（ii）直接进入龙虾的血淋巴（血液），在那里，胺改变了肌肉和感觉神经元长时间运作的方式。在中枢神经系统中，就像调光开关在电路中的作用一样，血清素细胞作为“增益调节器”，使特定的通路在很长一段时间内发挥更好或更坏的作用。目前的研究将继续我们对这些有趣的神经元的调查，询问它们是如何被激活的，并将开始旨在询问这些含有5 -羟色胺的神经元是否在功能上表现出任何变化，作为社会地位变化的长期后果。对于章鱼胺神经分泌细胞，我们计划进行研究，旨在确定它们的生理作用，了解它们是如何被激活的，询问它们如何以及在哪里与相应的含血清素的神经元相互作用，并询问这些细胞的子集是否选择性地支配爪子，在切换到从属行为中起任何直接作用，就像当动物失去一只大爪子时看到的那样。我们所有研究的重点都是在神经元层面上理解动物之间社会互动的短期和长期后果。我们正在研究的龙虾模型具有充分的生物化学、生理学、解剖学和行为学研究，在解决这些问题方面具有许多优势。

9728551 Kravitz Serotonin has been linked to aggression in a wide and diverse range of species, including man. In vertebrates, lowered levels of this amine, possibly coupled with elevated levels of norepinephrine, have been linked to a particular kind of impulsive violence. While great interest is centered on this research, it is difficult in vertebrate systems, because of the large number of neuronal elements involved, to link amines and aggression at the level of single neurons and the precise changes taking place in the nervous system accompanying violent behavior. In invertebrate systems, with their limited numbers of large identifiable neurons, the analysis of complex behavioral processes, like aggression, can be brought to the level of the precise cells thought to be essential for the behavior. This application continues our studies exploring the function of identified single nerve cells from the lobster central nervous system (cns) that contain and utilize the amines serotonin and octopamine (the invertebrate equivalent of norepinephrine). We believe that these two amines have opposing actions on at least the postural component important in agonistic (fighting) behavior in lobsters. The serotonin cells that are the focus of our studies are neurosecretory cells. These cells release serotonin at two sites: (i) within the central nervous system, where it influences pathways having to do with posture and escape; and (ii) directly into the haemolymph (blood) of the lobster, where the amine changes the ways that muscles and sensory neurons function for prolonged periods of time. Within the cns, much in the same way that dimmer switches work on electrical circuits, the serotonin cells function as "gain-setters" that make particular pathways function better or worse for lengthy periods of time. The present studies will continue our investig ations of these interesting neurons, asking how they are activated, and will begin studies aimed at asking whether these serotonin-containing neurons show any changes in functioning as a long-term consequence of changes in social status. With the octopamine neurosecretory cells we plan studies aimed at defining their physiological roles, learning how they are activated, asking how and where they interact with the corresponding sets of serotonin-containing neurons, and asking whether a subset of these cells that selectively innervate the claws, serve any direct role in the switch to subordinate behavior seen when animals lose one of their large claws. The emphasis in all of our studies is on understanding, at a neuronal level, the short-and long-term consequences of social interactions between animals. With its well studied biochemistry, physiology, anatomy and behavior, the lobster model we are examining, offers many advantages in addressing such issues.