Neural Mechanisms of Dominance Behavior

动物之间的社会关系影响它们的行为，并通过影响控制行为的神经回路和反应来做到这一点。社会地位和行为之间的主要联系是通过释放神经调节剂来实现的，神经调节剂在神经系统内具有广泛的和有针对性的影响。5-羟色胺是一种神经调节剂，在包括灵长类动物、啮齿动物、鱼类和甲壳类动物在内的多种脊椎动物和无脊椎动物中，参与了社会秩序行为的表达。将5-羟色胺的作用与优势地位的表达联系起来的神经机制在甲壳类动物中研究得最彻底，尤其是龙虾和小龙虾。在目前的资助期间，小龙虾的社会优势地位被发现可以预测神经调节剂5-羟色胺对大翻转行为神经回路的影响。在孤立的小龙虾和社会优势的小龙虾中，5-羟色胺增强了外侧巨人(LG)尾部翻转命令神经元对其正常机械感觉输入的反应，并抑制了从属动物的细胞。这些差异是由于5-羟色胺受体群体的相应差异造成的。本提案继续这项研究，通过确定调节自由行为动物LG的5-羟色胺的来源，并询问在不同社会地位的动物中，5-羟色胺在哪里以及如何对LG产生不同的影响。将在打斗过程中测量自由行为的小龙虾的血液中5-羟色胺的水平，并使用标准的电生理技术测量LG对5-羟色胺、5-羟色胺激动剂和拮抗剂的反应。

Social relationships among animals influence their behavior, and do so by affecting the neural circuits and responses that control behavior. A primary link between social status and behavior occurs through the release of neuromodulators that have both widespread and targeted effects within the nervous system. One neuromodulator, serotonin, has been implicated in the expression of social ordering behaviors in a wide range of vertebrates and invertebrates, including primates, rodents, fish and crustaceans. The neural mechanisms that link serotonin's effects to the expression of dominance status have been studied most thoroughly in crustaceans, particularly lobsters and crayfish. During the current grant period the social dominance status of a crayfish was found to predict the effect of the neuromodulator serotonin on the neural circuit for the taiflip behavior. Serotonin enhances the response of the Lateral Giant (LG) tailflip command neuron to its normal mechanosensory input in isolated crayfish and in socially dominant crayfish, and inhibits the cell in subordinate animals. The differences result from corresponding differences in the population of serotonin receptors. The present proposal continues this research by determining the sources of serotonin that modulate LG in freely behaving animals, and by asking where and how serotonin has its different effects on LG in the animals of different social status. Blood levels of serotonin in freely behaving crayfish will be measured during fights, and the responses of LG to serotonin, serotonin agonists and antagonists will be measured with standard electrophysiological techniques.