通过内在情绪调节和学习记忆的指引,动物行为展现出很强的可塑性和灵活性。这种对生存环境的自适应特征对生物的生存繁衍至关重要。为研究这一类行为可塑性的神经环路机制,本项目拟利用秀丽线虫模式系统,结合行为学、遗传学和光神经生理学对特定的和学习记忆相关的神经环路进行系统的解析。在前期工作中,我们发现线虫对温度以及化学物质浓度均表现出可靠的学习记忆能力; 并用其自身分布式的神经网络来驱动灵活多变的趋温和趋化行为。更有研究发现,对控制人的负面情绪起重要作用的五羟色胺能有效调节线虫的学习和记忆功能。在本项目的支持下,我们将 (1) 通过发展全脑钙成像和光遗传学的手段来监测和操纵所有相关神经元的活动,并寻找记忆在神经环路中的表达和读取方式; (2)分析负面情绪(如饥饿所产生的焦虑)是如何改变趋温和趋化行为;(3)相关的神经调节剂是如何作用在神经环路并改变其动力学性质的。

Modulated by internal emotional states and guided by learning and memory, animal behaviors exhibit high flexibility and plasticity. Such self-adaptation in a changing environment is critical for the survival and multiplication of an animal. To investigate the neural mechanisms underlying behavioral plasticity, we propose to use C. elegans as a model system to dissect the neural circuit underlying behavioral plasticity by integrating behavior, genetics, and optical neurophysiology. In previous work, we have discovered that C. elegans show reliable learning and memory abilities when exposed to temperature and chemical stimuli. Driven by a distributed neural network, worms exhibit flexible thermotactic and chemotactic behaviors. Moreover, studies have shown that serotonin, a biogenic amine that plays critical roles in mediating aversive emotions in human, can also effectively modulate learning and memory in C. elegans. Next, we will first use "whole brain" calcium imaging technique and optogenetic method to monitor and manipulate all neurons underlying a defined sensorimotor behavior, and to search for the neural mechanisms for memory encoding, storage and retrieval. Second, we will investigate how aversive emotions (such as stress caused by hunger) would affect C. elegans thermotaxis and chemotaxis. Third, we will probe how neuromodulators mediate the dynamics of the neural circuit.