Neuroendocrine regulation of socially-driven circadian rhythms

虽然昼夜节律的社会调节存在于各种各样的动物中，但我们目前缺乏对昼夜节律和社会经验之间联系的神经内分泌机制和行为意义的理解。我的研究计划的长期目标是确定社会经验在社会行为的神经内分泌调节中的作用。夜间活动的裸体型电鱼由于其电通讯信号的易处理性和可塑性，已成为研究昼夜节律的功能和社会调节机制的良好动物模型。这项研究的主要目的是确定5-羟色胺能系统在裸体形鱼Brachythopomus gauderio电信号昼夜节律调节中的作用。为了进一步研究社会相互作用与电信号昼夜节律性之间关系的社会意义和机制，拟议的研究将：1)阐明5-羟色胺受体1A和2A在调节EOD昼夜节律中的作用；2)确定社会驱动的电信号昼夜节律变化的社会意义；3)确定下丘脑-垂体-肾上腺(HPA)轴中央调节中心5-羟色胺受体1A和2A的表达与下丘脑神经元活动的关系。这项拟议的工作具有创新性，因为它：1)使用电信号模型作为B.Gauderio神经内分泌调节底物在体内的直接实时公共广播；2)实施一种综合的实验方法，结合药理学、分子、组织学和行为学技术来描述5-羟色胺能-HPA途径在社会互动期间电信号昼夜节律变化中的作用。这个项目的结果有望产生重要的积极影响，因为它们将促进我们对昼夜节律调节的社会影响机制的了解，以及昼夜节律对不同社会状态的敏感性。

Although social regulation of circadian rhythms is found in a wide variety of animals, we currently lack an understanding of the neuroendocrine mechanisms and the behavioural significance underlying the connection between circadian rhythms and social experience for a socially-relevant behaviour. The long-term objective of my research program is to determine the role of social experience in the neuroendocrine regulation of social behaviours. Due to their electrocommunication signals' tractability and plasticity, the nocturnal gymnotiform electric fish have emerged as an excellent animal model to study the function and the mechanism of social regulation of circadian rhythms. The main objective of the proposed research is to determine the role of the serotonergic system on the regulation of the circadian rhythm of the electric signals of the gymnotiform fish, Brachyhypopomus gauderio. To further characterize the social significance and the mechanisms underlying the relationship between social interactions and electric signal circadian rhythmicity, the proposed research will: 1) clarify the role of the serotonin receptors 1A and 2A in the regulation of the EOD circadian rhythm; 2) determine the social significance of socially-driven changes in the electric signal circadian rhythm; and 3) determine the relationship between the expression of the serotonin receptors 1A and 2A in the central regulatory centers of the hypothalamic-pituitary-adrenal (HPA) axis and hypothalamic neuronal activity. The proposed work is innovative because it: 1) uses the electric signal model as a direct real-time in vivo public broadcast of B. gauderio's neuroendocrine regulatory substrates, and 2) implements an integrative experimental approach that combines pharmacological, molecular, histological and behavioural techniques to describe the role of the serotonergic-HPA pathway on changes in the electric signal's circadian rhythm during social interactions. The results from this project are expected to have an important positive impact because they will advance our knowledge on the mechanisms mediating social influences on the regulation of circadian rhythms, and on the sensitivity of circadian rhythms to different social states.