“家”和“窝”包含丰富的空间记忆和情感成分。长年离家在外的近三亿农民工面临各种压力，如何助其应对负面情绪是个严峻的社会问题。我们的前期结果显示，在旷场中一旦建立起“窝”概念的小鼠会明显改变对恐惧的本能防御行为。作为已长期合作的团队，我们基于这一发现和近年发展的多种研究神经环路的新技术，拟进一步完善结构和功能兼顾的解析神经元网络的标记系统、以及解析神经突触和全脑环路的多尺度成像系统，并与转基因动物、光遗传学、钙成像、电生理、行为学等手段集成，获得“窝”概念形成过程各阶段的窝相关网络、阴影防御网络及其与各阶段窝相关网络之间的相互作用和相应的多模态的信息集成，解析“窝”概念形成的学习记忆和“窝”这样的习得性记忆调控视觉恐惧防御行为的环路机制。新技术对环路研究具有普适性和转化前景；机理研究可能为如何帮助流动人群适应新环境，改善身心健康，促进社会稳定提供生物学依据，兼具科学意义和社会价值。

“Home”for human and “nest” for animals are complex concepts involving both spatial memory and emotional components. Our preliminary studies have demonstrated that mice can significantly change even their innate defensive responses to fear caused by visual cue after they established the concept of “nest” of “safe space” in the test box through conditioning. In this proposal, the team, which has established close collaboration for years, will take advantages of the expertise of all members to further improve broadly applicable new techniques and methods, including virus-based tracing systems that can be used to reveal the structures and study the functions, and super-resolution imaging tools to determine the site of proteins in synapse, and fast and sensitive imaging system with sub-cellular resolution for whole brain range mapping. Then, we will integrate these tools with others such as optogentics, chemogenetics, calcium imaging, electrical recording and behaviors to: 1) map out the neuronal networks across the whole brain for defensive responses to fear caused by visual cue and nest; 2) obtain the changes of the networks/circuits during the learn and memory processes to establish the concept of nest; 3) study the interactions between the two types of networks during looming stimulation at the different stages in the process forming the concept of nest; and 4) collect the information from the other modalities. By detailed and systematic analyses, we will elucidate the circuit mechanisms for the formation of the concept of nest, how the learnt memory modulates the innate defense responses. The techniques/methods/tools we attempt to develop and establish are suitable for basically all circuit studies and thus have great potential to be transferred into commercial products. The results from the mechanistic studies will provide neurobiological basis for measurements to accelerate the process of forming the concept of nest so as to help the mobile population to accommodate with new environments and improve their emotional conditions, leading to a more coherent society. Therefore, the results from this application should have significant impacts on science as well as society.