Three-dimensional wide-field fluorescence microscopy for transcranial mapping of cortical microcirculation

Abstract

Wide-field fluorescence imaging is an indispensable tool for studying large-scale biodynamics. Limited space-bandwidth product and strong light diffusion make conventional implementations incapable of high-resolution mapping of fluorescence biodistribution in three dimensions. We introduce a volumetric wide-field fluorescence microscopy based on optical astigmatism combined with fluorescence source localization, covering 5.6×5.6×0.6 mm3 imaging volume. Two alternative configurations are proposed exploiting multifocal illumination or sparse localization of point emitters, which are herein seamlessly integrated in one system. We demonstrate real-time volumetric mapping of the murine cortical microcirculation at capillary resolution without employing cranial windows, thus simultaneously delivering quantitative perfusion information across both brain hemispheres. Morphological and functional changes of cerebral vascular networks are further investigated after an acute ischemic stroke, enabling cortex-wide observation of concurrent collateral recruitment events occurring on a sub-second scale. The reported technique thus offers a wealth of unmatched possibilities for non- or minimally invasive imaging of biodynamics across scales.

Multifocal fluorescence video-rate imaging of centimetre-wide arbitrarily shaped brain surfaces at micrometric resolution

“…MFIAS is a flexible technique that can be easily integrated into RUSH or other macroscopes, such as digital single lens reflex (SLR) systems 42 (Extended Data Fig. 1a ).…”

“…These signals exhibit a high correlation with signals obtained from two-photon microscopy. The SLR system 42 , 43 achieves a lateral resolution below 10 μm in a 7-mm-diameter FOV (Supplementary Note 1.3.2 ) and has demonstrated cellular resolution for fixed NSC-34 neurons 57 (Supplementary Fig. 5 ).…”

Multimodal optoacoustic imaging: methods and contrast materials

“…239 Recently, microparticles have also been used to realize similar super-resolution approaches in FL and OA imaging. [240][241][242] Further developments in multimodal contrast materials should not only focus on improving their efficiency of signal generation but also optimizing the biodistribution properties, targeting capacity, biodegradability, and biocompatibility to reduce toxicity and administered doses.…”

Unveiling Fundamentals of Multi-Beam Pulsed Laser Ablation in Liquids toward Scaling up Nanoparticle Production

“…In particular, DOE beam splitters can split the incident laser beam into any number of beams along a line or in a 2D pattern and maintain other parameters of the light source (beam size, divergence, and polarization). Modern DOEs are flexible and reliable devices that can be easily incorporated into advanced optical systems and are currently widely used in applications such as laser material processing [ 26 , 27 , 28 ], optical sensing [ 29 , 30 ], lithography [ 31 ], and fluorescence microscopy [ 32 ]. It is reasonable to expect that multi-beam irradiation offered by DOEs can help to bypass the PLAL-generated cavitation bubble both temporally (the same ablation conditions per beam can be achieved at lower laser repetition rates) and spatially (lower beam scanning speeds are needed).…”