DEVELOPMENT OF fMRI COMPATIBLE REVERSIBLE DEACTIVATION

功能磁共振成像兼容可逆失活的开发

基本信息

批准号：
6891414
负责人：
STEPHEN G LOMBER
金额：
$ 17.29万
依托单位：
UNIVERSITY OF TEXAS DALLAS
依托单位国家：
美国
项目类别：
财政年份：
2004
资助国家：
美国
起止时间：
2004-06-01 至 2007-05-31
项目状态：
已结题

项目摘要

DESCRIPTION (provided by applicant): The development of functional magnetic resonance imaging (fMRI) has greatly expanded our ability to examine neural processing while subjects perform a variety of perceptual, cognitive, or motor tasks. fMRI permits the simultaneous examination of functional activity in many different brain regions and provides a better understanding of how multiple regions work in concert to produce particular behaviors. The next necessary step in the evolution of this approach is to deactivate a specific region in the brain, while a subject is being scanned, to determine the contribution of this site to the activity of its functional network -- by examining the activity of other network components in the absence of this region. To accomplish this goal, we propose to develop a reversible deactivation approach that is fMRI-compatible. The development of this technique will be based on a well-established cryoloop technique in which a cooling device is chronically implanted in behaving animals. We propose a four-phase development program. In phase 1 (development), we will develop a non-metallic cooling device capable of deactivating specific regions of the cerebral cortex. In phase 2 (testing), we will test the device in the behaving cat by cooling regions of primary visual cortex (V1) while the animal performs a visual orienting task. Once we establish device reliability, and can produce behavioral deficits, we will anesthetize the cats and examine the function of the device in the fMRI to confirm compatibility. In phase 3 (implementation), we will chronically implant the device over a region of V1 in non-human primates that have been trained to make visually guided saccades. If V1 is successfully deactivated, saccades to targets within the scotoma should be abolished. The monkeys will be tested while performing the task in the magnet and images will be collected before, during, and after cooling deactivation. We will also examine the distant deactivation consequences on area MTN5 and the superior colliculus while the monkeys view expanding and contracting visual flow during fixation. Finally, in phase 4 (evaluation), we will administer radiolabelled 2-deoxyglucose during cooling so that we may compare the autoradiograms with the deactivation images collected in the magnet. In summary, we expect to fully develop and test a device to reversibly deactivate sites in the brain during behavioral testing in the magnet. Such a development should have wide appeal and will greatly advance our ability to dissect functional circuits with fMRI.

描述（由申请人提供）：功能磁共振成像（fMRI）的发展极大地扩展了我们在受试者执行各种感知、认知或运动任务时检查神经处理的能力。功能磁共振成像可以同时检查许多不同大脑区域的功能活动，并可以更好地了解多个区域如何协同工作以产生特定行为。这种方法发展的下一个必要步骤是在扫描受试者时停用大脑中的特定区域，通过检查其他网络的活动来确定该位点对其功能网络活动的贡献组件在没有该区域的情况下。为了实现这一目标，我们建议开发一种与功能磁共振成像兼容的可逆失活方法。该技术的开发将基于成熟的cryoloop技术，其中将冷却装置长期植入行为动物体内。我们提出了一个四阶段的发展计划。在第一阶段（开发）中，我们将开发一种能够使大脑皮层特定区域失活的非金属冷却装置。在第二阶段（测试）中，我们将在动物执行视觉定向任务时通过冷却初级视觉皮层（V1）区域来测试行为猫的设备。一旦我们确定了设备的可靠性，并且可以产生行为缺陷，我们将对猫进行麻醉，并在功能磁共振成像中检查设备的功能以确认兼容性。在第 3 阶段（实施），我们将长期将该设备植入非人类灵长类动物的 V1 区域，这些动物已经接受过视觉引导扫视训练。如果 V1 成功停用，则应取消对暗点内目标的扫视。猴子将在磁铁中执行任务时进行测试，并在冷却停用之前、期间和之后收集图像。我们还将检查当猴子在注视过程中观察扩大和收缩的视觉流时，对 MTN5 区域和上丘的远距离失活后果。最后，在第 4 阶段（评估），我们将在冷却过程中施用放射性标记的 2-脱氧葡萄糖，以便我们可以将放射自显影图与磁体中收集的失活图像进行比较。总之，我们期望全面开发和测试一种设备，在磁铁的行为测试过程中可逆地停用大脑中的位点。这样的发展应该具有广泛的吸引力，并将极大地提高我们用功能磁共振成像解剖功能电路的能力。