NOVEL MULTI-MODALITY MRI AND TRANSCRANIAL STIMULATION TO STUDY BRAIN CONNECTIVIY

这个子项目是许多研究子项目中的一个 由NIH/NCRR资助的中心赠款提供的资源。子项目和 研究者（PI）可能从另一个NIH来源获得了主要资金， 因此可以在其他CRISP条目中表示。所列机构为 研究中心，而研究中心不一定是研究者所在的机构。 磁共振成像（MRI）提供人脑和其他器官的高分辨率扫描，其中图像对比度主要基于质子弛豫时间的区域差异。 磁共振对组织物理化学的各个方面的敏感性导致了功能性MRI（fMRI）技术的发展，该技术可以超越简单解剖成像的范围来探测组织生理学和病理学。 众所周知的血氧水平依赖性（BOLD）方法依赖于有效T2弛豫时间对血红蛋白铁的氧化态的敏感性，而血红蛋白铁的氧化态又对氧消耗速率的改变敏感。BOLD信号在刺激呈现后的变化反映了神经元激活的变化，因此可以用于绘制大脑中的功能通路。 结合BOLD对比度和扩散张量成像（DTI）[1]，已经实现了对与功能性脑区相关的结构基础的评估，这允许可视化连接大脑不同部分的神经元轴突束或束。然而，由于这些功能性技术揭示了参与特定功能的大脑网络，因此它们不能单独证明特定区域对特定功能至关重要。 功能磁共振成像和经颅磁刺激（TMS）的组合，这是非侵入性和无痛的，可以暂时破坏局灶性大脑区域的活动[2]。这种结合是提高对大脑活动中特定区域贡献的认识的初步尝试。因此，在这个项目中，我们建议开发一种革命性的方法，集成TMS，功能磁共振成像和DTI，使用BNL的4-T MR扫描仪，从而提供大脑功能和连接的独特窗口。

This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. Magnetic resonance imaging (MRI) provides high-resolution scans of the human brain and other organs where image contrast is based principally on regional differences in proton relaxation times. The sensitivity of magnetic resonance to various aspects of tissue physical chemistry led to the development of a functional MRI (fMRI) technique that can probe tissue physiology and pathology beyond the scope of simple anatomical imaging. The well-known blood oxygenation level-dependent (BOLD) method relies on the sensitivity of the effective T2 relaxation time to the oxidation state of hemoglobin iron, which in turn is sensitive to alterations in oxygen consumption rate. Changes in the BOLD signal following presentation of stimuli reflect changes in neuronal activation, and can therefore be used to map functional pathways in the brain. The assessment of the structural basis associated with the functional brain areas have been achieved combining BOLD contrast and diffusion tensor imaging (DTI) [1], which permits the visualization of the tracts or bundles of neuronal axons that connect different parts of the brain. Nevertheless, since these functional techniques reveal the brain networks involved in specific functions, they cannot alone prove that a specific area is essential for a particular function. The combination of fMRI and transcranial magnetic stimulation (TMS), which is non-invasive and painless, can transiently disrupt activity in focal brain regions [2]. This combination was the initial trial to improve the acknowledgement about the contribution of specific areas in brain activity. Therefore, in this project we propose to develop a revolutionary methodology integrating TMS, fMRI and DTI, using BNL's 4-T MR scanner, so as to provide the unique windows on brain function and connectivity.