Single-shot quantitative aberration and scattering length measurements in mouse brain tissues using an extended-source Shack-Hartmann wavefront sensor

Abstract

Deep fluorescence imaging in mammalian brain tissues remains challenging due to scattering and optical aberration-induced loss in signal and resolution. Correction of aberrations using adaptive optics (AO) requires their reliable measurement in the tissues. Here, we show that an extended-source Shack-Hartmann wavefront sensor (ESSH) allows quantitative aberration measurements through fixed brain slices with a thickness up to four times their scattering length. We demonstrate in particular that this wavefront measurement method based on image correlation is more robust to scattering compared to the standard centroid-based approach. Finally, we obtain a measurement of the tissue scattering length taking advantage of the geometry of a Shack-Hartmann sensor.

Enhanced neuroimaging with a calcium sensor in the live adultDrosophila Melanogasterbrain using closed-loop adaptive optics light-sheet microscopy

“…All results presented in this paper without AO are instrument-corrected so that the reported gain brought by AO only comes from the correction of sample induced aberrations. The wavefront calculation procedure has been described in detail in a previous article [23], and the slopes calculation is based on a Southwell geometry. The slopes calculation process based on intercorrelations follow the pseudo-code described in Anugu et al [24].…”

Enhanced neuroimaging with a calcium sensor in ex-vivo Drosophila melanogaster brains using closed-loop adaptive optics light-sheet fluorescence microscopy

“…All results presented in this paper without AO are instrument-corrected so the reported gain brought by AO only comes from the correction of sample induced aberrations. The wavefront calculation procedure has been described in detail in a previous article, 23 and the slopes calculation is based on a Southwell geometry. The slopes calculation process based on intercorrelations follows the pseudo-code described in Anugu et al 24 …”

Fast Adaptive Optics in optically sectioned fluorescence microscopes for functional neuroimaging

“…By using an extended-source Shack-Hartmann wavefront sensor (ESSH), our approach allows to preserve speed and accuracy of the direct wavefront sensing method and takes advantage of existing labelling methods of biological samples [1]. It relies on the crosscorrelation of images of an extended source obtained through a microlens array and requires to be coupled to an optical sectioning method in order to provide a guide plane: it is thus interestingly compatible with various fluorescence imaging techniques already implemented for 3D imaging such as two-photon microscopy (TPEF) [2] or light-sheet fluorescence microscopy (LSFM) [3].…”