Functional MRI investigation of spinal cord resting-state networks and their physiological relevance

静息状态的功能性磁共振成像（fMRI）研究提供了关于皮质功能的丰富信息，我的实验室的研究已将这种能力扩展到脑干（BS）和脊髓（SC）。静息状态fMRI研究是指在没有任务或刺激时发生的协调血氧水平依赖性（BOLD）反应，因此神经活动与内定向认知相对应。我的实验室已经获得证据，在静息状态下，SC中的协调信号可能与通过BS降低SC兴奋性的调节有关。静息状态协调的概念因此延伸到整个中枢神经系统，以及认知以外的功能。迄今为止，我的实验室研究已经证明了功能磁共振成像数据中生理噪声的主要来源，它们的相对贡献，以及如何减少/消除它们。这使我们能够确认在静息状态下，BS和SC区域内部和之间存在广泛的协调，并开始研究这种协调如何被认知过程改变。本研究的目标是：1)进一步加深我们对人类SC神经生理学和功能如何持续调节的理解；2)开发用于识别和研究这种调节的分析工具。具体目标如下：目标1：描述静息状态下横跨BS和SC的协调信号的一致网络，包括区域和连接、发生率和连接强度。目标2：确定健康人群中rs-网络的变化，以及静息状态连接与各种功能之间的关系（基于先前的研究），包括；1)疼痛敏感性，2)与心脏和呼吸功能相关的运动活动，3)自主调节。目标3：开发和验证用于分析和可视化BS和SC静息状态分析结果的软件工具。拟议的研究将为大约6名研究生提供丰富的培训机会，以及本科论文项目，并将有助于我们对健康人体BS和SC功能的全面了解。它还将改进我们可用来进行这项研究的工具。预计对这些网络/系统及其持续调控的理解将支持未来的研究，以更好地理解各种疾病和损伤的影响。连续静息状态功能可能是维持许多系统内稳态的核心，因此可能是我们生理的一个非常重要的特征。因此，拟议的研究有可能对我们对涉及脑干和脊髓的所有功能的理解产生重大影响。

Functional magnetic resonance imaging (fMRI) studies of the resting-state have provided a wealth of information about cortical function, and research in my lab has extended this capability to the brainstem (BS) and spinal cord (SC). Resting-state fMRI studies refer to coordinated blood oxygenation-level dependent (BOLD) responses that occur when no task or stimulus is applied, and therefore the neural activity corresponds with internally-directed cognition. My lab has obtained evidence that coordinated signaling in the SC, in the resting-state, is likely related to descending regulation of SC excitability, via the BS. The concept of resting-state coordination thus extends to the entire central nervous system, and to functions other than cognition. Research in my lab to date has demonstrated the primary sources of physiological noise in fMRI data, their relative contributions, and how to reduce/remove them. This enabled us to confirm that there is extensive coordination within and across BS and SC regions in the resting-state, and to begin to investigate how this coordination is altered by cognitive processes. The proposed research has the goals of 1) furthering our understanding of human SC neurophysiology and how function is regulated on a continuous basis, and 2) developing analysis tools for identifying and studying this regulation. The specific objectives are: Objective 1: Characterize the consistent networks of coordinated signaling in the resting-state across the BS and SC, in terms of regions and connections, rates of occurrence, and connection strengths. Objective 2: Identify variations in rs-networks across healthy people, and the relationships between resting-state connectivity and various functions (based on prior research), including; 1) pain sensitivity, 2) motor activity related to cardiac and respiratory function, 3) autonomic regulation. Objective 3: Develop and validate software tools for analysis and visualization of results for resting-state analyses in the BS and SC. The proposed research will provide a wealth of training opportunities for approximately 6 graduate students, as well as undergraduate thesis projects, and will contribute to our overall understanding of BS and SC function in healthy humans. It will also improve the tools we have available to do this research. It is expected that an understanding of these networks/systems and their continuous regulation will support future research into better understanding the effects of a wide variety of diseases and effects of injuries. Continuous resting-state function may be central to maintaining homeostasis of a number of systems and therefore may be a very important feature of our physiology. The proposed research thus has the potential for significant impact on our understanding of all functions that involve the brainstem and spinal cord.