Table 1. Microscope specifications and imaging settings.
| Minaturized microscope | Two-photon microscope | |
|---|---|---|
| Illumination method | Epifluorescence | Two-photon |
| Frame rate | 10 Hz | 10 Hz |
| Maximum frame rate | 50 Hz (at 630 x 630 pixels) | 30 Hz (at 750 x 800 pixels) |
| Lens numerical aperture | 0.5 NA | 0.8 NA |
| Lens magnification | 2x | 16x |
| Field-of-view | 1 mm x 1 mm (630 pixels x 630 pixels) |
300 x 320 μm (750 x 800 pixels) |
| Excitation wavelength | 458 nm | 910 nm |
| Excitation power | <1 mW | 25 mW |
| Optical resolution (X)a | 3.52 μm | 0.59 μm |
| Optical resolution (Y)a | 6.12 μm | 0.57 μm |
| Optical resolution (Z)a | 33.35 μm | 2.78 μm |
| Photobleachingb | 1.013 ± 0.019 a.u. | 0.994 ± 0.004 a.u. |
| Movement correction | <1.6 μm (95th percentile) | <1.6 μm (95th percentile) |
a The optical resolution was emperically obtained by calculating the full width at half maximum (FWHM) of a Gaussian-curve fitted intensity profile of a subresolution (0.2 μm diameter) fluorescent bead.
b Photobleaching was defined as the fraction average fluorescence in the 30 s post-stimulation period compared to the 30 seconds pre-stimulus period (5–6 minute interval). A value of 1.0 indicates no change.