Linking Functional Imaging, Neurophysiology & Anatomy

描述(由申请人提供)： 功能磁共振成像(FMRI)、磁源成像(MSI)和扩散张量成像(DTI)等脑成像方法正在迅速发展成为分析正常和异常脑功能的基本工具。这项研究的总体目标是加强我们对使用这些成像技术测量的信号与潜在神经活动之间的关系的理解。我们建议在麻醉猕猴身上进行一系列实验，以检验功能性脑成像信号之间的相关性，特别是fMRI的BOLD信号、MSI的模拟电流源和DTI对白质束的成像，并使用“金标准”单单位和多单位电生理记录和神经解剖示踪技术。具体目标是1)测量刺激引起的脑功能成像信号在幅度、位置和时间上的变化，并将它们与潜在神经活动的变化联系起来；2)将来自DTI的非侵入性解剖连通性测量与使用神经解剖学技术得出的连通性相关联；以及3)将基于fMRI和MSI时间序列的协方差的功能连通性测量与来自DTI和神经解剖学研究的解剖连通性进行比较。这些实验代表了一项独特的合作努力，目的是在同一动物身上结合几种技术，以更好地理解现代成像技术在不同刺激条件下跟踪神经系统变化的能力，并揭示复杂感觉能力所需的电路。我们的努力是第一批弥合成像、神经生理学和解剖学之间差距的努力之一，这是将来自猕猴的丰富电生理记录数据与人类大脑皮层联系起来的关键一步，也是理解复杂功能(如物体识别和语言等认知过程所需的感觉整合)的关键一步。

DESCRIPTION (provided by applicant): Brain imaging methods such as functional magnetic resonance imaging (fMRI), magnetic source imaging (MSI) and diffusion tensor imaging (DTI) are rapidly evolving as essential tools for assaying normal and abnormal brain function. The overall goal of this research is to enhance our understanding of the relationship between the signals measured using these imaging techniques and the underlying neural activity. We propose to conduct a series of experiments in anesthetized macaque monkeys to examine the correlation between functional brain imaging signals, specifically the BOLD signals of fMRI, the modeled current sources of MSI, and the imaging of white-matter tracts with DTI, with "gold standard" single and multi-unit electrophysiological recordings, and neuroanatomical tracing techniques. The specific aims are 1) To measure the stimulus evoked changes in magnitude, location and timing of functional brain imaging signals and relate them to changes in underlying neural activity, 2) To correlate non-invasive anatomic connectivity measures derived from tractography of DTI with connectivity derived using neuroanatomical techniques, and 3) To compare measures of functional connectivity based on the covariance of fMRI and MSI time-series with anatomic connectivity derived from DTI and neuroanatomic studies. These experiments represent a unique collaborative effort to combine several techniques in the same animal to generate a better understanding of the ability of modem imaging techniques to track changes in the nervous system under varying stimulus conditions and to uncover the circuitry necessary for complex sensory abilities. Our efforts are among the first to bridge the gap between imaging, neurophysiology and anatomy, an essential step in relating the wealth of electrophysiological recording data from macaque monkeys to the human cortex, and in understanding complex functions such as the sensory integration necessary for cognitive processes like object recognition and language.