自由运动小鼠全脑皮层可达微型化三光子成像技术研究

解码生物大脑工作的脑科学已经成为21世纪科学发展的前沿方向和宏伟目标，而能够观测大脑基本神经处理单元工作方式的显微镜则成为研究的首要目标。尤其是，能够无障碍甚至无感的佩戴在小动物头部并允许其自由运动的微型化显微镜成为热点方向，并被Nature Methods评为2018年的年度方法。然而，佩戴式高分辨显微镜在不实行有创介入的情况下的成像深度依然有限，目前还远无法实现人们非常关注的小动物整个脑皮层深度范围全部可达的成像。本项目提出使用红外二区高穿透深度的激光激发波长，利用三光子成像原理，结合微型化物镜、新型宽带空心光子晶体光纤等技术实现全新一代的微型化三光子高时空分辨显微镜。此项目的顺利实施，将能够在自由运动小鼠上实现无创条件下1mm深度的脑神经功能活动观察，从而具备覆盖全脑皮层深度可达的最小神经单元高时空分辨的功能成像能力,为生物学家完整分析整个脑皮层神经的功能图谱提供有力工具。

Brain decoding has become one of the frontier research field and magnificent goal of scientific development in the 21st century. Furthermore, the microscopy which can observe the basic structural unit of the neural network of the brain has become the primary goal. In particular, miniature microscopy, which can be accessible or even senseless to the head of small free-moving animals, has become a hot topic, and been named as Method of The Year by Nature Methods in 2018. However, the imaging depth of wearable high-resolution microscopy is still quite limited without invasive intervention. At present, it is of great concern to brain scientists that it is impossible to achieve the imaging of the whole cortex of small animals, limited by the imaging depth. In this project, a new miniaturized three-photon microscopy with high spatial-temporal resolution is proposed. It is based on the principle of three-photon excitation, miniaturized objective lens and new broadband hollow photonic crystal fibers. The successful implementation of this project will enable observation of neurological activity of the free-moving mice to the depth of 1 mm under non-invasive conditions, thus providing high spatial and temporal resolution functional imaging capability of the smallest neuron unit covering the whole cerebral cortex. Successful development of this new miniaturized microscopes will certainly contribute to the complete analysis of functional maps of the whole cortical nerve by biologists.