仙琴蛙求偶/择偶行为决策及其神经电生理机制

Sexual selection is a co-evolutionary process between males and females with courtship and mate choice, thus few decisions are as important to an individual as decision-making in courtship and mate choice. There are extensive unidirectional researches on evaluations about options and results of decision-making during courtship or mate choice, however, both the properties of decision processes and the underlying neural mechanisms are still largely unknown, so we still cannot understand the essence of these decision-making completely. Based on previous studies, we propose the following hypotheses: 1) The decision-making in both courtship and mate choice are dynamic processes in which animals evaluate internal and external information repeatedly before making a decision, associating with dynamic brain activities (gene expression and neural information); 2) Compared with other decisions, there are similar but different brain networks and neural mechanisms involved in courtship and mate choice. Different from other vertebrates relying on multimode signals, the decisions in courtship and mate choice in frogs rely almost entirely on vocal communications. As it is easy to manipulate and analyze the acoustical signals, Emei music frog (Babina daunchina) is used as an animal model in the present project. The dynamic processes and the underlying neuro- electrophysiological mechanisms of the decisions during courtship and mate choice will be explored entirely by event-related potential (ERP) and local field potential (LFP) with behavioral experiments in frogs. This project may help us to understand the essences and the underlying neural mechanisms of decision-making in courtship and mate choice, and has vital scientific importance for exploring brain functions, sexual selection and the evolution of species.

求偶/择偶决策是动物最重要的行为决策之一，是相互促进和协同进化的过程。前人针对求偶或择偶的选项评估和决策结果进行了大量单向性研究，但决策的动态过程及神经机制均不清楚，因此尚不能完整揭示求偶/择偶决策的本质。基于既往研究，我们提出如下假设：①求偶/择偶决策是互为反馈、相互促进、并对自身条件和外部信息反复评估和最终择优的动态过程，该过程伴随着大脑活动（基因表达和神经信息等）的动态变化；②求偶/择偶决策与其他行为决策既有共享的、又有特异性的参与网络和脑机制。不同于其它脊椎动物基于多模信号，蛙类求偶/择偶决策几乎完全依赖声音通讯；声音信号也便于分析和操纵。因此，本项目以仙琴蛙为模型，结合行为实验、事件相关电位和局部场电位等技术，以"整体和动态"的思路探讨求偶/择偶决策的动态过程及神经电生理机制。本项目的实施将阐明该决策的动态特征及潜在的神经机制，对探讨大脑功能、性选择和物种进化具有重要的科学意义。

求偶/择偶决策是动物最重要的行为决策之一。基于既往研究，我们提出两点假设：（1）求偶/择偶决策是互为反馈、相互促进、并对自身条件和外部信息反复评估和最终择优的动态过程，该过程伴随着大脑神经活动的动态变化；（2）求偶/择偶决策与其他行为决策既有共享的、又有特异性的参与网络和脑机制。为验证实验假设，我们进行了如下实验：利用行为实验，探讨决策过程在行为层面的动态变化，以及刺激信号声学特性与动物行为之间的联系；利用事件相关电位(event-related potentials, ERP)实验，研究大脑处理声音信号的加工模式；利用局部场电位和脑网络方法研究行为决策过程中脑电的动态变化及各脑区间的功能联系。. 通过本项目的研究，我们发现：（1）雄性仙琴蛙的竞争受到社群因素的强烈影响，竞争策略表现出动态性；同时在竞争过程中，顺序线索比空间线索更为重要；（2）声音感知具有右耳优势，且是注意与结构非对称性共同作用的结果，据此提出了右耳优势的混合模型；（3）仙琴蛙存在静息态脑网络，该网络与其听觉感知功能相关联；（4）仙琴蛙存在非对称性的听觉功能网络，即中脑与端脑间的上行连接左侧强于右侧，而下行连接相反。这一结果与仙琴蛙的右耳优势匹配，说明从右侧端脑下行的抑制性连接可能是导致右耳优势的部分原因；（5）仙琴蛙注意脑网络受声音信号的生物学意义强度调制，具有更高性吸引力的洞内鸣叫能诱发出更强的大脑网络连接；（6）声音辨别和鸣声类型识别分别发生在100ms和200ms；（7）鸣声的第一个音节在声音通讯中起着至关重要的作用；（8）脑电近似熵的变化反映着大脑的听觉处理和功能复杂度；（9）脑电与行为受光周期同步调制。这些结果表明：求偶/择偶决策是一个动态过程，并伴随着大脑信息的动态变化；求偶/择偶决策具有特异性的参与网络和脑机制。这些结果对探讨大脑功能、性选择和物种进化具有重要的科学意义。. 本项目已发表SCI论文14篇，中文核心3篇，尚有6篇SCI文章尚在审稿或撰写之中。