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利用 资源由NIH/NCRR资助的中心拨款提供。子项目和 调查员(PI)可能从NIH的另一个来源获得了主要资金， 并因此可以在其他清晰的条目中表示。列出的机构是 该中心不一定是调查人员的机构。 磁共振成像(MRI)提供了对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各方面的敏感性导致了功能磁共振成像(FMRI)技术的发展，该技术可以探测组织的生理和病理，超出了简单的解剖成像的范围。众所周知的血氧水平依赖(BOLD)方法依赖于有效T2弛豫时间对血红蛋白铁的氧化状态的敏感性，而血红蛋白铁又对氧耗率的变化敏感。在刺激呈现后，BOLD信号的变化反映了神经元激活的变化，因此可以用来绘制大脑中的功能路径。结合大胆对比和扩散张量成像(DTI)[1]，可以对连接大脑不同部分的神经轴突束或束进行可视化，从而实现了与大脑功能区域相关的结构基础的评估。然而，由于这些功能技术揭示了涉及特定功能的大脑网络，它们不能单独证明特定区域对特定功能是必不可少的。 功能磁共振成像和无创无痛的经颅磁刺激(TMS)相结合，可以暂时扰乱大脑局部区域的活动[2]。这一组合是提高对特定区域在大脑活动中的贡献的认识的初步试验。因此，在这个项目中，我们建议开发一种革命性的方法，利用BNL的4-T磁共振扫描仪，集成TMS、fMRI和DTI，从而提供关于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.