Journal Article

Fast high-resolution miniature two-photon microscopy for brain imaging in freely behaving mice

Hu, Yanhui, Zhang, Yunfeng, Zong, Weijian, Zhou, Zhuan, Lu, Yang, Wang, Aimin, Wu, Runlong, Fan, Ming, Xu, Yangyang, Li, Yijun, Jia, Hongbo, Chen, Liangyi, Li, Jinghang, Rong, Hao, Wu, Haitao, Li, Mingli, Cheng, Heping

2017

Overview

FHIRM-TPM is a miniature two-photon microscope capable of imaging fluorescently labeled neurons in the brains of freely behaving mice. It allows for imaging of spines or recording of neural activity with a frame rate up to 40 Hz. Developments in miniaturized microscopes have enabled visualization of brain activities and structural dynamics in animals engaging in self-determined behaviors. However, it remains a challenge to resolve activity at single dendritic spines in freely behaving animals. Here, we report the design and application of a fast high-resolution, miniaturized two-photon microscope (FHIRM-TPM) that accomplishes this goal. With a headpiece weighing 2.15 g and a hollow-core photonic crystal fiber delivering 920-nm femtosecond laser pulses, the FHIRM-TPM is capable of imaging commonly used biosensors (GFP and GCaMP6) at high spatiotemporal resolution (0.64 μm laterally and 3.35 μm axially, 40 Hz at 256 × 256 pixels for raster scanning and 10,000 Hz for free-line scanning). We demonstrate the microscope's robustness with hour-long recordings of neuronal activities at the level of spines in mice experiencing vigorous body movements.

• Publisher: Nature Publishing Group US,Nature Publishing Group
• Subject: 14/35 / 14/63 / 14/69 / 631/1647/245/2225 / 631/1647/328/2057 / 631/1647/328/2235 / 631/1647/334/1874/345 / 631/378 / 64/60 / Animal behavior / Animals / Behavior, Animal / Bioinformatics / Biological Microscopy / Biological Techniques / Biomedical and Life Sciences / Biomedical Engineering/Biotechnology / Biosensors / Brain / Brain - cytology / Brain - diagnostic imaging / Brain - physiology / Crystal fibers / Cytological Techniques - methods / Dendrites / Dendritic spines / Femtosecond pulsed lasers / Femtosecond pulses / High resolution / Innovations / Life Sciences / Medical imaging / Mice / Microscopes / Microscopy / Microscopy, Fluorescence, Multiphoton - methods / Miniaturization - methods / Neuroimaging / Observations / Photonic crystals / Photons / Proteomics / Raster scanning / Rodents / Scanning / Synaptic transmission