The research paper entitled “rapid body imaging of mouse and zebrafish brains by confocal light field microscope” was published online by Wang Kai, researcher of the center for brain science and intelligent technology innovation, Chinese Academy of Sciences, Shanghai brain science and brain like research center, and State Key Laboratory of neuroscience. In this study, a new body imaging technology, confocal light field microscopy (CLFM), was developed to perform fast and large-scale volume imaging of neural and vascular networks in deep brain tissues of living animals. How to integrate information and influence behavior of large-scale neurons across brain regions is a core problem in neuroscience. To solve this problem, we need tools to capture the dynamic changes of a large number of neurons at a higher spatial and temporal resolution. The traditional imaging tools such as confocal microscope and two-photon microscope are based on point scanning and have low time resolution, so it is difficult to study the rapid changes of neurons in a wide range of brain regions. Therefore, in recent years, researchers have been committed to developing faster imaging methods. Among various new technologies, the light field microscope has the potential and has been widely concerned. Its characteristic is that it can record the signals from different depths of the object at the moment of single exposure of the camera, and reconstruct the whole three-dimensional body through the reverse convolution integral algorithm to realize fast volume imaging. It has been preliminarily applied to small model animals such as online worms, zebrafish juveniles and so on. < / P > < p > there are two problems in traditional optical field microscope, which limit its application in biological imaging. First of all, the reconstructed results will be out of line years. Wang Kai’s research group developed a new type of extended field of view light field microscope, Xlfm) solved this problem, and applied it to the whole brain functional imaging of free behavior zebrafish juveniles. It was the first time to record the changes of the whole brain neuron activity in the complete predatory behavior of zebrafish juveniles. Secondly, the existing optical field microscopic imaging technology lacks the ability of optical sectioning and cannot image the thicker tissue, such as mouse brain. It is the key to improve the image quality and be widely used to improve the signal-to-noise ratio (SNR) by filtering the background signal except the focal layer in the large sample with the same optical slicing ability as the confocal microscope. However, the traditional confocal microscope using laser point by point scanning and conjugate point pinhole detection to reduce out of focus noise is not suitable for three-dimensional optical field microscope. In the face of this challenge, the research team innovatively proposed the concept of generalized confocal detection, which can be combined with the three-dimensional imaging strategy of optical field microscope, effectively filter out the background noise without sacrificing the volume imaging speed, and improve the sensitivity and resolution. This new optical field microscopy technology is called confocal optical field microscope. < / P > < p > the team tested the imaging ability of confocal light field microscopy on different animal samples. The team members performed whole brain calcium imaging on the embedded live zebrafish juveniles. Comparing the imaging results of confocal and traditional light field microscopy, it was found that the image resolution and signal-to-noise ratio were improved after adding optical sectioning ability, and more weak calcium activities could be detected. Furthermore, a confocal optical field microscope and a high-speed three-dimensional tracking system were combined to conduct whole brain calcium imaging of free-moving zebrafish juveniles. The spatial resolution of 2 x 2 x 2.5 μ m 3 and the time resolution of 6 Hz were achieved in the volume of 0.800 μ m x 200 μ M. Thanks to the higher resolution and sensitivity, the changes of calcium ion activity in single neuron of zebrafish juveniles in the process of predation on Paramecium can be recognized. < / P > < p > the team members have verified the imaging effect of confocal light field microscope on mouse brain. Calcium imaging of visual cortex of awake mice can simultaneously record the activity of nearly 1000 neurons in the volume of (800 μ m x 150 μ m), with the maximum depth of about 400 μ M, and more than 100000 frames can be recorded stably for more than 5 hours without obvious photobleaching. The team members further tried to use confocal light field microscope to image blood cells in the brain of rats, with a depth of 600 μ m and a shooting speed of 70 Hz. Meanwhile, the flow of blood cells in thousands of blood vessel branches was recorded and the velocity of blood cells was calculated, which was more than 100 times higher than the previous traditional imaging method. < / P > < p > the research team has demonstrated that confocal light field microscopy has higher resolution and sensitivity in the brains of free-living zebrafish juveniles and mice, which provides a new tool for studying the function of large-scale neural networks and vascular networks. At the same time, the technology is not only suitable for brain tissue imaging, but also can flexibly adjust the resolution, imaging range and speed according to the types of samples to be imaged, which can be applied to the rapid dynamic imaging of other thick tissues. Under the guidance of Wang Kai, the research was mainly completed by doctoral students Zhang Zhenkun, Bai Lu and assistant researcher Lin Lin. Yu Peng and Zhang Tianlei of Wang Kai’s research group, Shi wanzhuo, undergraduate of University of science and technology of China, and Li Funing of Du Jiulin research group made contributions, and researcher Du Jiulin participated in the cooperation and gave guidance. The research was supported by the experimental animal platform of brain intelligence Excellence Center of Chinese Academy of Sciences. The research was funded by the Ministry of science and technology, the Chinese Academy of Sciences, the National Natural Science Foundation of China and Shanghai Municipality. < / P > < p > Figure 1. (1) schematic diagram of confocal light field microscope. (2) different from the traditional light field microscope, confocal light field microscope uses sheet illumination, selectively excites a part of the sample, and scans in the direction of vertical illumination, and the collected signal is filtered out of the range of focal layer by the shielding plate. The 3D information in the focal layer can be obtained by reconstructing the collected image. < / P > < p > Fig. 2. (left) an example of predation behavior of juvenile zebrafish. 0 s was the time when zebrafish ate Paramecium. (right) the activity of neurons in two different brain regions recorded by confocal light field microscope during zebrafish predation. The arrow refers to a single neuron activated in the process. < / P > < p > Fig. 3. (left) complex vascular networks in the visual cortex of mice captured by confocal light field microscope. Six volumes photographed at different depths were connected to form a three-dimensional structure with a depth of 600 μ M. (middle) the plane projection of the vascular network at the depth of 100 μ m to 250 μ m, and the color represents the average flow velocity of blood cells in different vascular branches. (right) the number of blood cells flowing through the five branches of blood vessels in the area indicated by the arrow in the figure over a period of time.