Year: 2026
Type: preprint
Abstract: How the cortex supports complex, naturalistic behavior can be revealed only in freely moving animals. Although head-mounted microscopes promise access to the neural dynamics underlying such behavior, fundamental trade-offs among field of view, spatial resolution, device weight, and background contamination have prevented cortex-wide single-neuron recording, leaving distributed cortical coordination largely inaccessible. To meet these challenges, we introduce COMET (C ortex-wide O bservational M iniature E pifluorescence T echnique ) , a 3.75-g head-mounted mesoscope that integrates an aberration-controlled wide-field optical design, uniform high-efficiency excitation and single-coaxial power-and-data transmission with an end-to-end denoising and signal-extraction pipeline. This enables cortex-wide calcium imaging at single-cell resolution in freely moving mice. COMET captures activity from >15,000 layer 2/3 neurons per 5-min recording over fields of view up to 10 mm in diameter while preserving natural behavior. Benchmarking against benchtop two-photon microscopy demonstrates high spatial concordance of detected neurons and matched event-level calcium dynamics. We apply COMET to social interaction to quantify region-specific engagement and to an auditory trace fear-conditioning task that requires natural movement and behavioral expression, revealing time-ordered changes in regional firing-rate structure and functional connectivity preceding a global conditioned response. COMET provides an open, lightweight hardware–software framework for linking single-neuron activity to cortex-scale network dynamics during freely expressed behaviors under changing internal or external conditions.
Authors: Changliang Guo, Mian Xie, Guohua Qiu, Jian Lu, Yuzhen Liu, Liying Qu, Yuanyuan Huang, Zhenran Guo, Jing Tian, Jingren Lin, Baoyi Zhang, Xuefei Zhang, Junjie Zhao, Xiang Liu, Haochen Long, Jingyi Ma, Bo Zhou, Xianxin Ye, Pingping Zhao, Jingjie Cao, Zhengan Lin, Zhimiao Zhang, Weijie Deng, Jian Wang, Wei Wu, Junwen Wang, Xiaohong Peng, Shiqun Zhao, Shuai Na, Haoyu Li, Wenhao Liu, Qiang Fu, Zengcai V. Guo, Weisong Zhao, Liangyi Chen
Institutions: Peking University, Center for Life Sciences, State Key Laboratory of Membrane Biology, Tsinghua University, Harbin Institute of Technology, University of Hong Kong, University of California, Los Angeles, Chinese Academy of Sciences, Changchun Institute of Optics, Fine Mechanics and Physics, University of Chinese Academy of Sciences, First Hospital of Jilin University, Shenzhen University
Language: English
Subfield: Biophysics
Domain: Life Sciences
Open Access status: green
OpenAlex ID: W7221912735