Fig. 1. Overview of in vivo super-resolution microscopy^[22-34]

Fig. 2. The principle of STED and its applications in vivo. (a) The principle of STED^[38]; (b) the STED in vivo imaging achieved for the first time^[24]; (c) comparison between two-photon STED imaging and two-photon imaging^[29]; (d) imaging of the mouse brain by combining adaptive optics and 3D-2P-STED^[30]

Fig. 3. The principle of SIM and its applications in vivo. (a) The principle of SIM^[13,38]; (b) imaging of the mouse brains by 2P-SuPER^[31]; (c) imaging of the mouse brain by combining adaptive optics and OS-SIM^[48]; (d) observation of head-fixed awake mice using a multiplexed, line-scanning structured illumination microscope^[33]

Fig. 4. The principle of MSIM and its applications. (a) The principle of iSIM^[51]; (b) imaging of the phantoms by NIR-II MSIM^[52]; (c) imaging of the zebrafish motoneurons by AO 2P-MSIM^[53]

Fig. 5. The principle of SMLM and its applications. (a) The principle of PALM/STROM^[38]; (b) visualization of the stepping behavior of endogenous dynamin in live neurons via MINFLUX^[64]; (c) imaging up to 80 µm deep in tissue with MINFLUX nanoscopy^[65]; (d) the principle of MINFLUX^[63]

Fig. 6. The principle of SOFI and its applications in vivo. (a) The principle of SOFI^[16];(b) the principle of SRRF^[68]; (c) imaging of the mouse brain by 2P-SRRF^[34]

Fig. 7. Three-dimension imaging method. (a) Confocal microscopy and Light sheet microscopy^[86]; (b) 4pi-STED^[87]; (c) 3D-MP-SIM^[88]

Fig. 8. Strategies for improving the imaging quality of in vivo super-resolution microscopy. (a) Multi-photon microscopy^[93]; (b) near-infrared imaging^[94]; (c) adaptive optics^[30]; (d) deep learning^[95]