Neural Mechanisms of Dominance Behavior

动物之间的社会关系通过影响控制行为的神经回路和反应来影响它们的行为。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，这些神经调节剂在神经系统内具有广泛和有针对性的作用。一种神经调节剂，血清素，在包括灵长类动物、啮齿动物、鱼类和甲壳类动物在内的许多脊椎动物和无脊椎动物的社会秩序行为的表达中都有牵连。在甲壳类动物中，特别是龙虾和小龙虾中，对将血清素影响与优势地位表达联系起来的神经机制进行了最彻底的研究。在当前的资助期内，小龙虾的社会优势地位被发现可以预测神经调节剂血清素对神经回路的影响。5 -羟色胺增强了孤立小龙虾和社会优势小龙虾侧巨尾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。这种差异是由血清素受体数量的相应差异造成的。目前的提议通过确定在自由行为的动物中调节LG的血清素的来源，并通过询问血清素在哪里以及如何对不同社会地位的动物的LG产生不同的影响来继续这项研究。在打斗过程中，将测量自由行为的小龙虾血液中的血清素水平，并使用标准的电生理技术测量LG对血清素、血清素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.