Connectome Analysis of the Nigrostriatal Neuronal Tract after Blast TBI

部署到阿富汗战争（持久自由行动）和伊拉克战争（ 伊拉克自由组织（OIF）因暴露于爆炸（bTBI）而遭受创伤性脑损伤（TBI）的风险很高 和其他类型的头部损伤。此外，暴露在发射肩射武器的冲击波中， 影响大脑，甚至在训练期间。所有严重程度的TBI均可导致慢性展开后干扰， 认知、行为、情感和身体功能。有大量证据表明创伤性脑损伤 (TBI)在多巴胺能系统中产生慢性缺陷，这可能有助于损伤后的认知功能。 SPiRE基金的目的是评估弥散MRI纤维束成像和网络分析的使用， 确定单次和重复模拟爆炸（激波管）暴露对 黑质纹状体相关束hTH-GFP报告大鼠将暴露于单一或重复的压力波， 30psi或40psi的峰值压力。这些压力是基于初步数据显示， 40 psi和30 psi的空间记忆缺陷。一系列行为结果测试，以评估运动，认知， 并测量与压力相关的功能。在模拟爆炸后4周，离体高清光纤 跟踪（HDFT）结合网络拓扑分析将被执行，以表征 黑质和纹状体神经元网络通路。还将评估小脑被盖区束。 初步的连接体分析表明，中脑和纹状体的连接受损后bTBI。损失 脑损伤后4周，脑组织中多巴胺能转运蛋白的表达有明显变化。初步成像 网络拓扑分析显示，黑质纹状体通路经历了更大的神经元网络重构， 组织比海马或杏仁核区域。多巴胺的免疫组织化学分析- 在成像后评估相关蛋白质。总的假设是，暴露于不同的模拟 冲击波超压将导致黑质纹状体完整性、多巴胺能标记物和 行为功能该应用程序符合SPiRE的目的，即支持高级调查人员寻求 在以前没有资助的领域探索新的研究方法。

Military personnel deployed to the wars in Afghanistan (Operation Enduring Freedom; OEF) and Iraq (Operation Iraqi Freedom; OIF) are at high risk of sustaining a traumatic brain injury (TBI) from exposures to a blast (bTBI) and other types of head injuries. Furthermore, exposure to blast waves from firing shoulder-fired weapons can affect the brain, even during training. TBI of all severities can result in chronic post-deployment disturbances of cognitive, behavioral, emotional, and physical functioning. There is extensive evidence that traumatic brain injury (TBI) produces chronic deficits in the dopaminergic system that may contribute to postinjury cognitive function. The goal of this SPiRE grant is to evaluate the use of diffusion MRI tractography and network analysis to determine the effects of single and repetitive simulated blast (shock tube) exposures on the integrity of nigrostriatal-associated tracts. hTH-GFP reporter rats will be exposed to single or repeated pressure waves at either peak pressure of 30psi or 40psi. These pressures are based on preliminary data demonstrating greater spatial memory deficits in the 40psi vs. 30psi. A battery of behavioral outcome tests to assess motor, cognitive, and stress-related function will be measured. At 4-weeks post-simulated blast, ex-vivo high-definition fiber tracking (HDFT) in conjunction with network topology analysis will be performed to characterize the integrity of substantia nigral and striatal neuronal network pathways. Ventral tegmental area tracts will also be assessed. Preliminary connectome analyses indicate that midbrain and striatal connectivity is impaired after bTBI. Loss of dopaminergic transporter protein was preliminarily observed after 4-week post-bTBI. Preliminary imaging network topological analysis showed that the nigrostriatal pathway underwent larger neuronal network re- organization after bTBI than hippocampal or amygdala regions. Immunohistochemical analyses of dopamine- related proteins will be assessed after imaging. The overall hypothesis is that exposure to varying simulated blast overpressures will result in graded reductions in nigrostriatal integrity, dopaminergic markers, and behavioral function. The application is in line with the SPiRE purpose to support senior investigators seeking to explore new research approaches in areas where they have not previously been funded.