CEREBRAL ORGANIZATION FOLLOWING COCHLEAR IMPLANT

描述（由申请人提供）：植入人工耳蜗后，听觉皮层在一段时间的剥夺后，其建立听觉信号处理的能力表现出显著的可塑性。我们的长期目标是了解和定义非初级听觉皮层在人工耳蜗植入后建立听觉功能的能力。这一努力需要阐明非初级听觉皮层在完整（听力）条件下对基本听觉引导行为的重要贡献，以及评估先天性耳聋受试者在人工耳蜗植入后的非初级听觉皮层的行为能力。该应用程序的第一个具体目的是确定非初级听觉皮层包含处理模式感知和空间定位的专门区域。在完整的猫中，我们将研究前听觉场和后听觉场（分别为AAF和PAF）对模式识别和听觉空间感知的贡献。每个区域都将随着冷却而可逆地失活，我们期望能够将模式识别和空间定位功能分别分离到AAF和PAF皮层。该研究的第二个目的是确定在发育早期（2个月大）植入人工耳蜗的先天性失聪（CD）猫是否可以建立听觉介导的行为。我们将测试动物是否能够在听觉辨别、检测和定位任务中达到高水平。前两个目标的结果将在Aim 3中结合在一起，在Aim 3中，我们将把Aim 2中检查的耳蜗植入的CD猫与Aim 1中使用的可逆失活技术结合起来，以确定早期耳蜗植入后非初级听觉皮层的特征正常功能图是否建立起来。为了实现这一目标，我们将在执行上述一系列听觉任务时，可逆地停用植入耳蜗的CD猫的AAF和PAF皮质，并将结果与Aim 1中完整猫的结果进行比较。这些研究的结果将直接适用于幼儿人工耳蜗植入的功能结果的临床情况。

DESCRIPTION (provided by applicant): Following implantation of a cochlear prosthetic, auditory cortex exhibits a remarkable plasticity in its ability to establish auditory signal processing after a period of deprivation. Our long-term goal is to understand and define the capabilities of non-primary auditory cortex to establish auditory function following cochlear implant. This endeavor requires the elucidation of the essential contributions that non-primary auditory cortex makes to fundamental aurally-guided behaviors in the intact (hearing) condition, as well as an assessment of the behavioral capabilities of non-primary auditory cortex following cochlear implant in congenitally deaf subjects. The first specific aim of this application is to determine that non-primary auditory cortex contains specialized regions for the processing of pattern perception and spatial localization. In intact cats, we will examine the contributions that the anterior and posterior auditory fields (AAF and PAF, respectively) make to pattern recognition and the perception of auditory space. Each area will be reversibly deactivated with cooling and we expect to be able to doubly-dissociate pattern discrimination and spatial localization functions to AAF and PAF cortices, respectively. The second aim in the study is to determine if congenitally deaf (CD) cats with cochlear prosthetics implanted early in development (2 months of age) can establish aurally-mediated behaviors. We will test if the animals are able to attain high performance levels on the auditory discrimination, detection, and localization tasks examined in Aim 1. The results of the first two aims are brought together in Aim 3, where we will combine the CD cats with cochlear implants examined in Aim 2 with the reversible deactivation techniques used in Aim 1 to determine if the characteristic normal functional cartography of non-primary auditory cortex is established following early cochlear implantation. To accomplish this, we will reversibly deactivate AAF and PAF cortices in the CD cats with cochlear implants while performing the battery of auditory tasks described above, and compare the results with those from the intact cats in Aim 1. The results from these studies will be directly applicable to clinical situations concerning the functional outcomes of cochlear implants in young children.