Does Contact Sport Induce Fibrillar Amyloid Deposition in the Brain?

项目摘要/摘要 反复脑震荡和亚脑震荡脑损伤，如在接触性运动和军事中所经历的 从长远来看，部署与破坏性的神经退行性疾病有关，例如慢性 创伤性脑病(CTE)和阿尔茨海默病(AD)，但它们之间的联系机制仍然存在 在很大程度上是难以捉摸的。众所周知，颅脑损伤可通过轴突显著诱导β淀粉样蛋白的增加。 损伤，有证据表明这会演变成淀粉样斑块，但其大小、持续时间和 这种增加的影响在活人身上还没有得到很好的研究，特别是在轻微的脑外伤中，这是 最常见的形式。诱导的有毒淀粉样蛋白的后果令人担忧，尤其是 考虑到最近的证据表明，β淀粉样蛋白可能通过 肾上腺素能系统，说明了一种新的途径，淀粉样蛋白可能通过该途径导致神经毒性，即使它 抬高是温和的，随后通过正常的生理过程或药物作用而清除 干预措施。虽然这对AD研究有巨大的影响，但它也增加了诱人的可能性 淀粉样蛋白是脑外伤后神经变性风险的一个重要因素，可能包括最轻微的 年轻运动员和服役人员经常接触的形式。幸运的是，有强大的和 测量活体大脑中的β淀粉样蛋白的灵敏方法。在目标1中，我们将采用最有效的、 定量PET/MR成像技术(具有动脉输入功能和隔室模型的11C-PIB) 灵敏地测量大学接触性运动运动员在一个赛季比赛前后的大脑淀粉样蛋白水平。 我们的主要假设是，本赛季结束后，全球皮质淀粉样蛋白的分布量将会更高。在……里面 目的2、探讨这一措施与创伤性轴索损伤相关措施的关系。 相关白质(使用DTI MRI的分数各向异性，同时采集到PET)，血浆 生物标志物和通过加速度计测量的客观暴露变量。虽然这是一个初步的 机械性研究，它可能为整个地区的诊断和预防方法带来重要的新方向 颅脑损伤的全部严重程度。

PROJECT SUMMARY/ABSTRACT Repetitive concussive and subconcussive brain trauma, as experienced in contact sports and military deployment, has been linked to devastating neurodegenerative disease in the long term, such as chronic traumatic encephalopathy (CTE) and Alzheimers disease (AD), but the mechanisms linking them remain largely elusive. It is well known that TBI can acutely induce increases in beta amyloid protein via axonal damage and there is evidence that this can evolve into amyloid plaques, but the magnitude, duration and implications of this increase have not been well studied in living humans, especially in mild TBI which is the most common form. The consequences of induced toxic amyloid species are worrisome, especially considering recent evidence that beta amyloid might directly stimulate production of tau protein via the adrenergic system, illustrating a new pathway through which amyloid may result in neurotoxicity even if its elevation is modest and subsequently cleared by normal physiological processes or pharmacological interventions. While this has enormous implications for AD research, it also raises the tantalizing possibility that amyloid is an important factor in the risk of neurodegeneration following TBI, perhaps including the mildest forms to which young athletes and service members are frequently exposed. Fortunately, there are robust and sensitive ways to measure beta amyloid in the living brain. In Aim 1, we will employ the most validated, quantitative PET/MR imaging techniques (11C-PiB with arterial input function and compartmental modeling) to sensitively measure brain levels of amyloid in college contact-sport athletes before and after a season of play. Our primary hypothesis is that global cortical amyloid distribution volume will be higher after the season. In Aim 2, we will explore relationships of this measure with related measures of traumatic axonal injury of associated white matter (using fractional anisotropy with DTI MRI, acquired simultaneously to PET), plasma biomarkers, and objective exposure variables measured by accelerometer. Although this is a preliminary mechanistic study, it could lead to vital new directions for diagnostic and preventative approaches across the full spectrum of TBI severity.