Long-term in vivo imaging of mouse spinal cord through an optically cleared intervertebral window

• Published in: Nature communications 2022-04, Vol.13 (1), p.1959-1959, Article 1959
• Main Authors: Wu, Wanjie, He, Sicong, Wu, Junqiang, Chen, Congping, Li, Xuesong, Liu, Kai, Qu, Jianan Y.
• Format: Article
• Language: English
• Subjects: 14/35; 14/69; 140/133; 631/1647/245/2226; 631/1647/328/2057; 631/378/87; 64/110; Animal models; Animals; Axotomy; Degeneration; Diagnostic Imaging; Disease Models, Animal; Fluorescence; Humanities and Social Sciences; Image resolution; Immunology; Inflammation; Inflammatory response; Mice; Microglia; Microglia - metabolism; multidisciplinary; Nervous system; Neurodegeneration; Neuroimaging; Neuronal-glial interactions; Nodes of Ranvier; Paralysis; Pathology; Peripheral nervous system; Raman spectra; Science; Science (multidisciplinary); Spinal cord; Spinal Cord - metabolism; Spinal cord injuries; Spinal Cord Injuries - pathology; Trauma
• ISSN: 2041-1723; 2041-1723
• DOI: 10.1038/s41467-022-29496-x

The spinal cord accounts for the main communication pathway between the brain and the peripheral nervous system. Spinal cord injury is a devastating and largely irreversible neurological trauma, and can result in lifelong disability and paralysis with no available cure. In vivo spinal cord imaging in mouse models without introducing immunological artifacts is critical to understand spinal cord pathology and discover effective treatments. We developed a minimally invasive intervertebral window by retaining the ligamentum flavum to protect the underlying spinal cord. By introducing an optical clearing method, we achieve repeated two-photon fluorescence and stimulated Raman scattering imaging at subcellular resolution with up to 15 imaging sessions over 6–167 days and observe no inflammatory response. Using this optically cleared intervertebral window, we study neuron-glia dynamics following laser axotomy and observe strengthened contact of microglia with the nodes of Ranvier during axonal degeneration. By enabling long-term, repetitive, stable, high-resolution and inflammation-free imaging of mouse spinal cord, our method provides a reliable platform in the research aiming at interpretation of spinal cord physiology and pathology. Wu et al. developed a technique for longitudinal imaging with subcellular resolution of the spinal cord without causing inflammation or microglia activation in live mouse through an optically cleared intervertebral window.