Direct visualization of longitudinal effects of drug therapy on white matter in diffuse injured brain

描述（由申请人提供）：本项目将提供高含量的数据，用于基础研究和临床前研究。基础研究方面：我们将使用一种新的高分辨率，皮层下，体内成像方法来填补关于弥漫性创伤性脑损伤在细胞水平上的动态知识的关键空白，在活小鼠的皮层下白质损伤后60天内。这些知识将为我们理解脑外伤后发生的进行性退行性变提供新的见解，并为未来的联合药物治疗优化治疗窗口。我们将在活体小鼠中使用放置在皮层下白质束上的永久植入微透镜获得这些图像，并使用多光子显微镜通过该透镜周期性成像。我们将揭示该区域轴突退化、小胶质细胞浸润和激活以及微血管变化的时空动态变化。临床前方面：我们还将使用我们观察到的3个关键结果来评估正在进行临床前试验的药物的疗效。这种药物，米诺环素，是一种fda批准的抗生素，在实验性创伤性脑损伤小鼠的几小时内给予单剂量，可以减少轴突损失和小胶质细胞激活。我们假设，在损伤后3天给予的剂量将具有相同的治疗效果，即显著(1)减少轴突损失和(2)减少小胶质细胞激活。我们进一步假设二甲胺四环素会显著改善微循环速率。扩大这种有前途的药物的治疗窗口将使其更好地转化为临床。

DESCRIPTION (provided by applicant): This project will provide high-content data that will be used for both basic and preclinical research. BASIC RESEARCH ASPECT: We will use a novel method of high-resolution, subcortical, in vivo imaging to fill critical gaps in knowledge about th dynamics of diffuse traumatic brain injury at a cellular level in subcortical white matter in live mice over a 60-day period post-injury. This knowledge will give us new insights into understanding the progressive degeneration that happens after TBI and for optimizing therapeutic windows for future combination drug therapy. We will obtain these images in live mice using a permanently implanted microlens positioned over a subcortical white matter tract and periodically image through this lens using a multiphoton microscope. We will reveal previously unseen spatio-temporal dynamics of axon degeneration, microglia infiltration and activation, and microvascular changes with cellular resolution in this region. PRECLINICAL ASPECT: We will also use 3 key outcomes from our observations to evaluate the efficacy of a drug which is now in preclinical trials. This drug, minocycline, is an FDA-approved antibiotic that has reduced axonal loss and microglial activation when given in a single dose within a few hours of experimental traumatic brain injury in mice. We hypothesize that a dose given 3 days post-injury will have the same therapeutic benefits of significantly (1) reducing axonal loss and (2) reducing microglial activation. We further hypothesize that minocycline will result in significant improvement in microcirculation rates. Widening the therapeutic window for this promising drug will better position it for translation to the clinic.