Neurophysiology Imaging Facility Core: Functional and Structural MRI

磁共振成像或MRI是基于组成不同脑组织的质子的核自旋特性。通过一系列卓越的工程成就，MRI现在被常规用于以三维方式可视化整个身体（包括大脑）的内部结构。 也许更令人印象深刻的是，大脑中的局部血液流动，其在灰质体积中的相对比例，以及其氧合水平，都可以在感觉和行为任务中进行评估。 后一种功能性磁共振成像（fMRI）技术现在被美国和世界各地几乎所有主要大学的研究人员用于探索感觉处理，执行功能和社会认知。在短短的二十年里，功能性磁共振成像革命将人类大脑的研究带到了神经科学的前沿，并塑造了社会对大脑活动及其所有精神功能和功能障碍的基础的理解。 在神经生理学成像设备（NIF）中，我们试图将人类fMRI这一新领域与动物脑生理学和解剖学的更详细研究联系起来，因为动物研究对于获得fMRI无法获得的神经回路结构和功能的详细信息仍然至关重要。NIF是一个集中的核心设施，为三个赞助机构（NIMH，NINDS和NEI）的广泛研究人员提供服务。 NIF中的结构和功能成像利用了最新的尖端成像技术，允许用户将联合收割机成像与其他侵入性技术（如微电极记录、药理学灭活或解剖学追踪）结合起来。在强磁场中测试动物需要开发各种MRI兼容设备，包括动物座椅，约束装置，奖励输送装置，眼睛位置跟踪摄像机和手动响应键。因此，该设施为用户提供了猴子功能磁共振成像的这些和其他关键组成部分，使他们能够以最小的发展开始他们的研究。设施工作人员协助调查人员进行实验设计，以及生产项目专用硬件（例如射频线圈），以优化数据收集。 使用过去几年开发的标准设置，该设施通常每天进行三次扫描，全部在非人类灵长类动物中进行。 一些会议专门用于高分辨率解剖扫描，使研究人员能够确定电极的位置，执行手术计划，并评估药物的扩散。 此外，该设施还提供解剖技术，如扩散张量成像（DTI）和锰束示踪，可与电生理研究或病变结合使用。 垂直扫描仪中的大多数扫描旨在评估神经功能。 通常，功能性磁共振成像扫描与侵入性程序相结合，例如可逆失活、皮质消融、药理学操作、皮质电图记录、电微刺激或来自慢性微丝阵列的记录。 在清醒的、行为正常的猴子身上，功能性磁共振成像和侵入性技术的常规组合使NIH校内研究计划成为进行非人类灵长类动物研究的独特场所。使用NIF核心设施的NIH研究人员正在研究与基本神经功能，动机，决策，情绪和抑郁相关的广泛主题。

Magnetic resonance imaging, or MRI, is based on the nuclear spin properties of protons comprising different brain tissues. Through a remarkable set of engineering achievements, MRI is now routinely used to visualize the internal structure of the entire body, including the brain, in three dimensions. Perhaps even more impressively, the regional flow of blood in the brain, its relative proportion in a volume of gray matter, and its oxygenation level, can all be evaluated during sensory and behavioral tasks. The latter technique of functional MRI (fMRI) is now used by investigators in nearly every major university in the country and around the world to explore sensory processing, executive function, and social cognition. In just two decades, the fMRI revolution has brought the study of the human brain to the forefront of neuroscience, and has shaped the societal understanding of brain activity and its basis for all mental function and dysfunction. In the Neurophysiology Imaging Facility (NIF), we attempt to link this new field fMRI in humans to more detailed studies of brain physiology and anatomy in animals, since animal studies remain crucial for obtaining detailed information the structure and function of neural circuits that fMRI cannot obtain. The NIF is a centralized core facility that offers services to a wide range of investigators in each of the three sponsoring institutes (NIMH, NINDS, and NEI). Structural and functional imaging in the NIF exploit the latest cutting-edge imaging technology, allowing users to combine imaging with other invasive techniques, such as microelectrode recordings, pharmacological inactivation, or anatomical tract tracing. Testing animals inside a strong magnetic field has required the development of a wide array of MRI-compatible equipment, including animal chairs, restraint devices, reward delivery apparatus, eye position tracking cameras, and manual response keys. The facility thus provides users with these and other critical components of monkey fMRI, allowing them to initiate their studies with minimal development on their part. The facility staff assists investigators with experimental design, as well as the production of project-specific hardware (e.g. radiofrequency coils) that allow for optimized data collection. Using a standard setup developed over the last years, the facility typically carries out three scanning sessions per day, all in nonhuman primates. Some of sessions are devoted to high-resolution anatomical scanning, which allows investigators to determine the position of their electrodes, perform surgical planning, and evaluate the spread of pharmacological agents. In addition, the facility offers anatomical techniques, such as diffusion tensor imaging (DTI) and manganese tract tracing, which can be used in combination with electrophysiological studies or lesions. Most of the scans in the vertical scanner are aimed at evaluation of neural function. Typically fMRI scans are combined with an invasive procedure, such as reversible inactivation, cortical ablation, pharmacological manipulation, electrocorticogram recordings, electrical microstimulation, or recordings from chronic microwire arrays. The routine combination of fMRI and invasive techniques in awake, behaving monkeys makes the NIH Intramural Research Program a unique site to perform nonhuman primate research. NIH investigators that use the NIF core facility are studying a wide range of topics related to basic neurological function, motivation, decision-making, emotion, and depression.