Mechanisms of multisensory rehabilitation in a primate model of hemianopia

项目摘要 中风或创伤对视皮层的损害通常会导致对侧失明或偏盲。 明显影响生活质量的状况。这个项目的目标是开发一种灵长类动物模型 偏盲的多感觉康复。尽管已经尝试了几种治疗策略 多年来，他们取得了有限的成功，大多局限于视觉运动定向的恢复，没有 视觉感知。最近，一种新的、简单的、非侵入性的感觉训练范例被开发出来 产生更有希望和更快的结果。这种范式包括重复地在时空上呈现 一致的视觉和听觉线索到达失明的半视野，它在回路中参与可塑性 处理视觉和听觉信号。偏盲猫的结果表明，在几周的时间里， 这样的多感官暴露，动物恢复了检测和定位视觉刺激并执行 对侧视野中的初级视觉模式辨别。类似的发现最近也在 两名人类患者，他们被给予了非常相似的多感觉康复范例，并能够 口头报告他们对先前失明的半边视野中视觉刺激的知觉。然而，这一程度 可恢复的视觉功能尚不清楚。要克服使用CAT模型进行以下操作的限制 为了探索这些局限性及其神经生物学基础，我们建议建立灵长类多感觉模型 康复，我们可以详细说明该范例的有效性、操作和神经关联。我们的 眼前的目标是研究与心理物理和心理健康相关的最紧迫的问题 偏盲多感觉康复的神经生理学结果，包括量化 视觉刺激检测和视觉特征辨别能力。为此，我们将评估行为 训练过的偏盲猴子在之前的一系列视觉心理物理任务中的感知能力 并评估多感觉康复后皮质下神经生理学特性的变化 以及皮质区(上丘和唇区)被认为是这种恢复的基础。这些结果将 为理解这种新的康复方法背后的机制奠定了基础 可以开发最佳的翻译策略来改善人类患者的这种情况。

Project Summary Damage to visual cortex by stroke or trauma often results in contralateral blindness, or hemianopia, a condition that markedly compromises quality of life. The goal of this project is to develop a primate model of multisensory rehabilitation from hemianopia. Although several therapeutic strategies have been tried over the years, they have met with limited success, mostly restricted to the recovery of visuomotor orienting without visual awareness. Recently, a novel, simple, noninvasive sensory training paradigm has been developed that produces far more promising and rapid results. This paradigm involves repeatedly presenting spatiotemporally congruent visual and auditory cues to the blinded hemifield, which engages plasticity within circuits that process both visual and auditory signals. Results from hemianopic cats have shown that, after several weeks of such multisensory exposure, animals recover the ability to detect and localize visual stimuli and perform rudimentary visual pattern discrimination in the contralesional field. Similar findings were recently obtained in two human patients, who were given a very similar multisensory rehabilitation paradigm, and were able to verbally report on their awareness of visual stimuli in the previously blind hemifield. However, the extent of visual capabilities that can be recovered is unknown. To overcome the limitations of using the cat model to explore these limits and its neurobiological bases, we propose to establish a primate model of multisensory rehabilitation with which we can detail the effectiveness, operation, and neural correlates of the paradigm. Our immediate objective is to examine the most pressing questions relating to the psychophysical and neurophysiological outcomes of the multisensory rehabilitation of hemianopia, including the quantification of visual stimulus detection and visual feature discrimination capacities. To do so we will assess the behavioral and perceptual capabilities of trained hemianopic monkeys on a battery of visual psychophysical tasks before and after multisensory rehabilitation and assess changes in the neurophysiological properties of subcortical and cortical areas (superior colliculus and area LIP) believed to underlie this recovery. These results will provide a foundation for understanding the mechanisms underlying this novel rehabilitative approach so that optimal translational strategies can be developed to ameliorate this condition in human patients.