Parallel multi-region adaptive optics module for high-resolution imaging in deep brain microendoscopy

Area of Science:

• Neuroscience
• Optical Engineering
• Biomedical Imaging

Background:

• Gradient refractive index (GRIN) lens microendoscopy offers deep brain access but suffers from off-axis aberrations degrading image quality.
• Conventional adaptive optics (AO) struggle with correction speed, imaging speed, and system compatibility for large fields of view (FOV).

Purpose of the Study:

• To develop an advanced AO system for simultaneous aberration correction in multiple subregions of GRIN lenses.
• To improve image quality, speed, and FOV in one-photon and two-photon microendoscopy.

Main Methods:

• Developed a parallel multi-region AO module using a spatial light modulator (SLM) for simultaneous correction in nine subregions.
• Integrated the module into one-photon and two-photon microendoscopes, combined with multi-focus illumination.

Main Results:

• Achieved near-diffraction-limited imaging over an enlarged FOV, extending the usable field radius by ~300% (from 105µm to 185µm).
• Demonstrated significant improvements in correction efficiency and imaging speed.
• Validated enhanced resolution and signal strength in fluorescent beads, brain tissue, and in vivo mouse hippocampus imaging.

Conclusions:

• The parallel multi-region AO system effectively corrects complex spatial aberrations in GRIN lens microendoscopy.
• This method provides a practical solution for high-resolution, high-speed deep brain imaging, especially at the FOV edges.