Method for Large-scale Quantitative Analysis of Myelin in Living Animals

摘要 多发性硬化症(MS)是一种中枢神经系统脱髓鞘疾病，影响超过230万人 世界各地的人们。其发病机制尚不清楚，诊断不及时。 足以防止进一步的神经退化。证据表明，大脑中的脱髓鞘是一种 多发性硬化症的重要损害与该病的认知缺陷密切相关。然而，它的临床意义 尚未完全确定，因为在体内不能长期观察到皮质髓鞘。在这里我们 建议发展研究活体动物皮质髓鞘的光学方法。一种新的成像方式将 即三次谐波产生显微镜(THGM)，这是我们最近演示的 周围神经系统完整神经中髓鞘的无标记显影。强大的成像能力 将开发适合于提高我们对皮质髓鞘形成的知识的能力。首先，THGM将被 在活体多发性硬化症动物模型中被验证用于探测皮质脱髓鞘和重新髓鞘形成。第二，波前 将实施控制，以促进在小鼠大脑深处对皮质髓鞘进行大规模THGM成像。 第三，通过图像复原和概率建模实现超分辨率THGM形态测量。 该项目成功完成后，将开启基础科学研究的新领域 转化医学阐明皮质脱髓鞘和轴突-神经胶质细胞相互作用 重新髓鞘形成。

Abstract Multiple sclerosis (MS) is a demyelinating disease of the central nervous system affecting more than 2.3 million people worldwide. The pathogenic mechanism is not well understood and the diagnosis does not occur early enough to prevent further neurodegeneration. Evidence suggests that demyelination in the cerebrum is an important lesion of MS correlating well with cognitive defects in the disease. However, the clinical significance has not been fully established because cortical myelin cannot be observed in vivo over a long period. Here we propose to develop optical methods for studying cortical myelin in living animals. A new imaging modality will be employed, namely third-harmonic generation microscopy (THGM), which we recently demonstrated for label-free visualization of myelin in intact nerves of the peripheral nervous system. Powerful imaging capabilities will be developed suitable for advancing our knowledge of cortical myelination. First, THGM will be validated for probing cortical demyelination and remyelination in living MS animal models. Second, wavefront control will be implemented to facilitate large-scale THGM imaging of cortical myelin in deep mouse brain. Third, super-resolution THGM morphometry will be achieved by image restoration and probabilistic modeling. Upon successful completion, this project will open a new field of investigations in basic science as well as translational medicine to elucidate the axon-glial cell interaction underlying cortical demyelination and remyelination.