Figure 1
From: Fast confocal fluorescence imaging in freely behaving mice
Principle of the optical method and expected optical sectioning. (A) The illumination and detection grid G is composed of square pinholes of size A arranged along a rectangular grid with a distance of AP between pinholes (P = 4 in this case). (B) Illumination intensity for multipoint-scanning confocal imaging Ii,conf plotted along x and z, corresponding to the illumination grid plotted in A. For |z| < zc (region inside the dotted white lines), the illumination cones corresponding to different pinholes are well-separated. The envelope of the detection PSF of the microscope objective is also shown (dotted green line). (C) Expected signals for a fluorescent plane as a function of its position zs for widefield imaging (dotted black line), regular (solid blue line) and differential (solid black line) multipoint-scanning confocal imaging. Signals were normalized by the constant I0 (equation 17). We chose a ratio between transmission of the detection optics in the confocal and widefield pathways Twide/Tconf = 1/4.5 (value corresponding to our optical setup). For regular multipoint-scanning imaging, the signal measured for |z| > 20 μm is equal to the pinhole density D (D = 1/P2 ≈ 0.06).
