Fig. 5

TIS window for long-term neural monitoring. a Representative images of the two-photon cortical neural imaging of a Thy1-EGFP mouse at various depths on days 0, 7, and 14 after TIS window establishment. The axial step was set as 5 μm. b long-term two-photon observation of dendritic spines through the TIS window at a depth of 150 μm. Green arrows show spines that were eliminated over 10 days; yellow arrows show spines that were formed over 10 days; cyan arrows show spines that were formed and then eliminated over 10 days; asterisks show spines that persisted through 10 days. c Representative images of the three-photon microscopy of synaptic imaging and neural cell body long-term monitoring in deep tissue. The axial step was set as 5 μm. Yellow arrows point to the spines that were distinguishable through the TIS window. The images were obtained using a 20 × objective. The excitation wavelengths were 920 nm (80 MHz, 140 fs) and 1300 nm (400 kHz, 50 fs) for two-photon microscopy and three-photon microscopy, respectively. MIP: maximum projection. Similar results were obtained in 3 mice