Boosting Neuroimaging: The Synergy of Adaptive Optics and Light-Sheet Fluorescence Microscopy
published on 01.19.2024
Images of neurons inside Drosophila brain taken with and without adaptive optics

As a new step towards better imaging solutions incorporating adaptive optics (AO), we recently demonstrated, in collaboration with several research groups from CNRS, a fast aberration correction method, designed as an AO module compatible with light-sheet fluorescence microscopy (LSFM) for enhanced neuroimaging of live samples.

Focusing on the Neuroscientific Challenge

In the dynamic realm of neuroscience, understanding the brain’s functional organization and connectivity poses a great challenge.
Indeed, to be able to unveil mechanisms behind neurodegenerative diseases like Alzheimer’s and Parkinson’s, demands advanced imaging techniques allowing to map the brain activity with high spatio-temporal resolution at large depths.
Such requirements led to the development of new 3D imaging strategies such as light-sheet fluorescence microscopy (LSFM).
Even though the technique is perfectly suited for live imaging (thanks to great spatio-temporal capabilities and minimal phototoxicity), LSFM still encounters limited imaging depth capability due to strong optical aberrations compromising signal-to-background ratio (SBR).


Overcoming Challenges and Pushing Boundaries thanks to AO-LSFM combination

In response to this limitation, adaptive optics (AO) emerges as a game-changing technology when integrated into LSFM setups to counteract optical aberrations.
Recently, our research consortium highlighted the transformative impact of AO on LSFM, employing direct wavefront sensing with an extended-scene Shack-Hartmann (ESSH) wavefront sensor (link here). As a proof of concept, we were able to show significant improvement of image quality in-depth with structural imaging of ex-vivo Drosophila brain.
In this new study, an enhanced AO-LSFM set-up which does not require any guide star and is compatible with calcium neuroimaging is demonstrated.
Using dual labelling in the Drosophila brain, a strongly scattering sample :
– Structural and calcium signal images down to 80 and 40 μm were reported respectively, with an increased contrast of at least a factor of 2.
– Fast AO correction at a speed up to 10 Hz was demonstrated, positioning the approach as a game-changer in 3D imaging and dynamic process observation in depth in scattering samples.


Next steps and Future Frontiers

The instrumental approach designed by the team offers a compact and versatile prototype for integration into various LSFM setups. Ongoing testing on different configurations reveals the potential for a commercial AO add-on.
Researchers now delve into new challenges such as light-sheet thickness and excitation optimization, showcasing the continuous evolution of AO-LSFM technology for even greater image quality and sensitivity.
In conclusion, with its potential to unlock the mysteries of the brain, AO-LSFM is one of the technologies standing at the forefront of neuroimaging innovation. To address current & future challenges in this promising field, we are dedicated to developing tailored adaptive optics solutions to propel research forward.

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