Quantitative characterization of human subcortical hemodynamic response

项目总结 人类大脑皮质下区域在从动态平衡到认知的功能中起着关键作用。然而，在那里 对人类皮质下健康的全面评估一直缺乏研究。定量表征 对于揭示各种神经退行性变的机制具有很大的潜力 阿尔茨海默氏症、亨廷顿氏症和帕金森氏症等疾病以及脑血管病理 作为创伤性脑损伤(TBI)。 在这里，我们使用功能磁共振成像(Fmri)来测量血氧水平依赖性。 (粗体)皮质下区域的反应。我们将创建简单的多感觉整合任务，以产生 这种短暂的大脑激活引起的大胆反应--即所谓的大胆血流动力学反应功能(HRF)。 我们还将使用各种磁共振成像方法，如质子密度加权成像(PDWI)和扩散张量 用于结构评估的成像(DTI)。BOLD HRF与PDWI和DTI相结合将显著实现 皮质下神经血管健康的完整评估，包括核体积的量化，白色 物质连通性，以及这些指标之间的相关性。在拟议的研究性研究中，我们将获得 这一新指标的健康控制数据库。 我们将开发一种新的生物力学传输模型来预测潜在的脑血流和 与粗大的高频射频相对应的氧代谢。我们还将开发一种简单但有效的线性流 基于电路类比的局部神经驱动血流反应机制模型 活动。该流动网络模型将通过动脉自旋标记灌流的流量测量进行验证。 磁共振成像。建议的模型将解决我们对皮质下脑血管知识的一个关键缺口。 生理学。 我们将测试我们的测量和建模方案，以表征大脑皮质下的高频信号。 创伤性脑损伤(TBI)人群。这将证明我们的指标作为临床诊断的可行性。 工具。所提出的实验和建模方案可以更广泛地应用于其他大脑区域， 比如大脑皮层。它将是一种非常有效和可靠的诊断工具，特别是对于神经科 导致无结构异常的功能缺陷的疾病和脑血管病理，如 蛛网膜下腔出血、早期阿尔茨海默病和轻度认知障碍。

Project summary Subcortical human brain regions play critical roles in functions from homeostasis to cognition. However, there has been a dearth of research on full assessments of human subcortical health. Quantitative characterization of subcortical responses has a great potential to unveil the mechanisms of various neurodegenerative disorders including Alzheimer's, Huntington's, and Parkinson's Disease and cerebrovascular pathology such as traumatic brain injury (TBI). Here, we use functional magnetic resonance imaging (fMRI) to measure the blood oxygen level dependent (BOLD) response in subcortical regions. We will create simple multisensory integration tasks that produce BOLD response evoked by this brief brain activation – so called BOLD hemodynamic response function (HRF). We will also use various MRI methods such as proton-density weighted imaging (PDWI), and diffusion tensor imaging (DTI) for structural assessments. BOLD HRF combined with PDWI and DTI will enable remarkably complete assessments of subcortical neurovascular health, including quantification of nuclear volumes, white matter connectivity, and correlations among these metrics. In the proposed research study, we will obtain health control database for this novel metrics. We will develop a novel biomechanical transport model to predict underlying cerebral blood flow and oxygen metabolism corresponding to BOLD HRFs. We will also develop a simple but effective linear flow model based on an electrical circuit analogy to show mechanisms of blood flow response driven by local neural activity. This flow network model will be validated with flow measurement from arterial spin labelling perfusion MR imaging. The proposed model will address a critical gap in our knowledge of subcortical cerebrovascular physiology. We will test our measurement and modeling schemes for characterization of subcortical HRFs in the mild traumatic brain injury (TBI) population. This will demonstrate the feasibility of our metrics as clinical diagnostic tools. The proposed experimental and modeling schemes can be applied more broadly to other brain regions, such as cerebral cortex. It will be a very effective and reliable diagnostic tools, especially for neurological disorders and cerebrovascular pathology that cause functional deficits without structural abnormality, such as subarachnoid hemorrhage, early stage Alzheimer's disease, and mild cognitive impairment.