Neural Mechanisms of Dominance Behavior

统治等级组织了所有社会性动物的社会行为，对它们做出贡献的行为一目了然。尽管社会支配地位无处不在，也很重要，但人们对其在任何物种中的神经基础知之甚少。5-羟色胺已被确认为一种神经递质，有助于调节脊椎动物和无脊椎动物的社会优势。尽管5-羟色胺在中枢神经系统中有许多作用和作用部位，但与社会支配地位相关的作用和作用部位在很大程度上是未知的。解决这个问题的一种方法是研究5-羟色胺如何影响有助于控制行为特定方面的神经回路，并确定这些影响如何随着社会支配地位的变化而变化。众所周知，小龙虾逃避行为的神经回路提供了一个机会，来确定动物社会地位的变化如何导致5-羟色胺对逃避神经回路兴奋性的影响发生变化。早期的工作表明，5-羟色胺对逃避的外侧巨细胞(LG)命令神经元兴奋性的影响从社会优势小龙虾的促进作用到从属小龙虾的抑制作用不等。已经在小龙虾中发现了两种5-羟色胺的分子受体，并描述了它们在小龙虾神经系统中的分布。该项目将检验这样一种假设，即5-羟色胺在显性和从属小龙虾中的作用差异是由于影响LG神经元兴奋性的5-羟色胺受体的分布或有效性的不同造成的。LG逃逸回路中受体分布的差异将使用受体的荧光标记抗体来确定。针对每个受体的5-羟色胺激动剂和拮抗剂将被用来确定它的激活如何在每种社会类型的动物中对5-羟色胺的影响做出贡献。这项研究将展示5-羟色胺受体的分布和作用的不同如何导致主力和从属小龙虾神经系统功能的差异。由于5-羟色胺的作用影响许多动物的社会地位，这些机制很可能在动物界广泛存在。这项工作将为来自格拉斯哥州立大学和行为神经科学中心(CBN)其他成员的一名博士后学生和几名本科生提供研究培训机会。这项研究将在CBN的攻击性和从属合作实验室中展示和讨论，从而为CBN的任务做出贡献。

Dominance hierarchies organize the social behavior of all social animals, and the behaviors that contribute to them are immediately recognizable. Despite the ubiquity and importance of social dominance, little is understood about its neural substrates in any species. Serotonin has been identified as a neurotransmitter that helps mediate social dominance in vertebrates and invertebrates. Although serotonin has many effects and sites of action in the central nervous system, the effects and sites that are relevant to social dominance are largely unknown. One approach to this problem is to examine how serotonin affects neural circuits that help govern specific aspects of behavior, and to determine how these effects change with social dominance status. The well-understood neural circuitry for escape behavior in crayfish provides an opportunity to determine how changes in an animal's social status lead to changes in the effect of serotonin on the excitability of neural circuits for escape. Earlier work has shown that serotonin's effect on the excitability of the lateral giant (LG) command neuron for escape varies from facilitation in socially dominant crayfish to inhibition in subordinate crayfish. Two molecular receptors for serotonin have been identified in crayfish, and their distributions in the crayfish nervous system have been described. This project will test the hypothesis that the differences in serotonin's effects in dominant and subordinate crayfish result from differences in the distribution or the efficacy of serotonin receptors that affect the LG neuron's excitability. Differences in receptor distribution in the LG escape circuit will be determined using fluorescently labeled antibodies to the receptors. Serotonin agonists and antagonists specific to each receptor will be used to determine how its activation contributes to the effect of 5-HT in each social type of animal. This research will show how differences in the distribution and action of serotonin receptors produce differences in nervous system function in dominant and subordinate crayfish. Because the action of serotonin affects social status in many animals, these mechanisms are likely to be widespread in the animal kingdom. This work will provide research training opportunities for a Post-doctoral student and a few undergraduates drawn from GSU and from other members of the Center for Behavioral Neuroscience (CBN). The research will be presented and discussed at the CBN's Aggression and Affiliation Collaboratories, and so contribute to the CBN mission.