High-resolution two-photon transcranial imaging of brain using direct wavefront sensing

Imaging of the brain in its native state at high spatial resolution poses major challenges to visualization techniques. Two-photon microscopy integrated with the thinned-skull or optical clearing skull technique provides a minimally invasive tool for in vivo imaging of the cortex of mice without activating immune response and inducing brain injury. However, the imaging contrast and spatial resolution are severely compromised by the optical heterogeneity of the skull, limiting the imaging depth to the superficial layer. In this work, an optimized configuration of an adaptive optics two-photon microscope system and an improved wavefront sensing algorithm are proposed for accurate correction for the aberrations induced by the skull window and brain tissue. Using this system, we achieved subcellular resolution transcranial imaging of layer 5 pyramidal neurons up to 700 mu m below pia in living mice. In addition, we investigated microglia-plaque interaction in living brain of Alzheimer's disease and demonstrated high-precision laser dendrotomy and single-spine ablation. (C) 2021 Chinese Laser Press

Automated summary

The challenge of imaging the brain at high spatial resolution has been addressed with the development of two-photon microscopy integrated with techniques like thinned-skull or optical clearing skull. However, the optical heterogeneity of the skull limits imaging depth to the superficial layer. Recent optimizations in adaptive optics and wavefront sensing algorithms have enabled subcellular resolution imaging of neurons and investigation of microglia-plaque interaction in living brains of mice with Alzheimer's disease.