MTA-SZTE Research Group for Cortical Microcircuits, Department of Physiology, Anatomy and Neuroscience, University of Szeged, Közép fasor 52, Szeged H-6726, Hungary.
Department of Applied and Nonlinear Optics, Institute for Solid State Physics and Optics, Konkoly-Thege M. u. 29-33, Budapest H-1525, Hungary; R&D Ultrafast Lasers Ltd., H-1539 Budapest, Hungary.
Brain Res Bull. 2018 Mar;137:277-284. doi: 10.1016/j.brainresbull.2018.01.003. Epub 2018 Jan 8.
Degradation of myelin sheath is thought to be the cause of neurodegenerative diseases, such as multiple sclerosis (MS), but definitive agreement on the mechanism of how myelin is lost is currently lacking. Autoimmune initiation of MS has been recently questioned by proposing that the immune response is a consequence of oligodendrocyte degeneration. To study the process of myelin breakdown, we induced demyelination with cuprizone and applied coherent anti-Stokes Raman scattering (CARS) microscopy, a non-destructive label-free method to image lipid structures in living tissue. We confirmed earlier results showing a brain region dependent myelin destructive effect of cuprizone. In addition, high resolution in situ CARS imaging revealed myelin debris forming lipid droplets alongwith myelinated axon fibers. Quantification of lipid debris with custom-made software for segmentation and three dimensional reconstruction revealed brain region dependent accumulation of lipid drops inversely correlated with the thickness of myelin sheaths. Finally, we confirmed that in situ CARS imaging is applicable to living human brain tissue in brain slices derived from a patient. Thus, CARS microscopy is potent tool for quantitative monitoring of myelin degradation in unprecedented spatiotemporal resolution during oligodendrocyte damage. We think that the accumulation of lipid drops around degrading myelin might be instrumental in triggering subsequent inflammatory processes.
髓鞘的降解被认为是神经退行性疾病（如多发性硬化症，MS）的病因，但目前对于髓鞘丢失的机制还没有明确的共识。最近有人提出，免疫反应是少突胶质细胞退化的结果，从而对 MS 的自身免疫起始提出了质疑。为了研究髓鞘分解的过程，我们用铜锌超氧化物歧化酶（Cuprizone）诱导脱髓鞘，并应用相干反斯托克斯拉曼散射（CARS）显微镜，这是一种非破坏性的、无需标记的方法，可对活体组织中的脂质结构进行成像。我们证实了先前的结果，即 Cuprizone 对大脑区域具有依赖性的髓鞘破坏性作用。此外，高分辨率的原位 CARS 成像显示，髓鞘碎片沿着有髓轴突纤维形成脂质滴。用定制的软件进行分割和三维重建对脂质碎片进行定量分析，结果显示，脂质滴在大脑中的积累与髓鞘厚度呈负相关，这与大脑区域有关。最后，我们证实原位 CARS 成像可应用于源自患者的脑切片中的活体人脑组织。因此，CARS 显微镜是一种强大的工具，可在少突胶质细胞损伤过程中以空前的时空分辨率对髓鞘降解进行定量监测。我们认为，围绕降解髓鞘积累的脂质滴可能在触发随后的炎症过程中起作用。
