Development of Miniature Two-photon Microscopes for Studying Brain Microcircuit Functions in Freely Moving Animals



Time: 9:30-10:30 on Thur.,Dec.28, 2023

Venue:Central Main Building 511, Tsinghua University

Speaker: Dr. Weijian Zong

Host: Dr. Jiamin Wu

Title: Development of Miniature Two-photon Microscopes for Studying Brain Microcircuit Functions in Freely Moving Animals



Understanding complex cognitive functions starts with an elucidation of how information is encoded and transmitted within individual brain microcircuit. To achieve this goal, we need recording techniques capable of capturing the activity of large populations of neurons with a temporal precision close to the timescale of spikes and a spatial resolution high enough to resolve their spatial organization. Moreover, these techniques should be compatible with well-established and well-validated behavioral paradigms. Traditional extracellular recording techniques have drawbacks in terms of their ability to identify genetically defined cell types and are of limited use for studies of subcellular dynamics. Two-photon (2P) functional imaging stands out by offering subcellular spatial resolution and near-spike temporal resolution, so it has emerged as one of the workhorses to study the coding and computational properties of neural populations. However, its application had been limited by the bulky nature of conventional 2P imaging systems, restricting studies to head-fixed animals. Over the last two decades, considerable progress has been made in the development of portable microscopes specifically tailored for freely-moving-animal functional imaging. This talk introduces our recent work in developing new generations of 2P miniscopes with resolution, field of view, speed, and z-scanning capability similar to that of 2P benchtop microscopes. I will highlight key applications from my group and our collaborators, showcasing how this technology revolutionizes our understanding of neural circuits. Additionally, I'll discuss our roadmap for future developments, poised to significantly expand the capabilities of current existing systems.



Weijian Zong is currently the group leader of the neurophotonics lab at the Kavli lnstitutefor Systems Neuroscience, Norwegian University of Science and Technology in Trondheim Norway. He had his postdoc training in the lab of Prof. Edvard Moser and Prof. May-Britt Moser. He holds a BSc in Electrical Engineering from Peking University and a Ph.D. in biophotonics from the Academy of Military Medical Sciences, supervised by renowned professors Heping Cheng and Ming Fan. His research has contributed significantly to the development of miniature two-photon microscopy for brain imaging in freely behaving mice (Zong et al, Nature Methods 201782021: and Cell 2022). Additionally, he has developed a series of advanced fluorescence imaging tools across broad topics, including light-sheet microscopy, super-resolution, and TIRF microscopy.