Visual motion processing by neurons in area MT of macaque monkeys with experimental amblyopia.
Visual motion processing by neurons in area MT of macaque monkeys with experimental amblyopia.
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DOI：
10.1523/jneurosci.3055-10.2010
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发表时间：
2010-09-08
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影响因子：
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通讯作者：
Movshon JA
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作者：
El-Shamayleh Y;Kiorpes L;Kohn A;Movshon JA
早期经验影响视觉系统的发育。眼部错位或单侧模糊通常会导致弱视，这种疾病已成为理解发育可塑性的标准。弱视的神经生理学研究几乎完全集中在纹状皮层的皮质处理的第一阶段。在这里，我们首次对弱视如何影响非人类灵长类动物的纹状体外皮层进行了广泛的研究。我们研究了猕猴（M. nemestrina），我们拥有详细的心理物理学数据，直接将生理发现与感知能力进行比较。由于这些受试者在运动辨别方面表现出缺陷，因此我们重点关注 MT/V5 区域，该区域在运动处理中发挥着核心作用。正常 MT 中的大多数神经元对通过任意一只眼睛呈现的视觉刺激的反应相同；大多数弱视患者强烈偏好刺激非弱视（同侧）眼。弱视眼驱动的神经元的汇总反应显示出对相干运动的敏感性降低，并且偏好更高的速度，这与行为测量一致。 MT 神经元随着时间的推移整合运动信息的能力比行为表现的预期更加有限；弱视眼驱动的神经元比另一只眼驱动的神经元的整合时间更短。我们的结论是，部分（但不是全部）与弱视相关的运动敏感性缺陷可以通过 MT 发育异常来解释。
Early experience affects the development of the visual system. Ocular misalignment or unilateral blur often causes amblyopia, a disorder which has become a standard for understanding developmental plasticity. Neurophysiological studies of amblyopia have focused almost entirely on the first stage of cortical processing in striate cortex. Here we provide the first extensive study of how amblyopia affects extrastriate cortex in nonhuman primates. We studied macaque monkeys (M. nemestrina) for which we have detailed psychophysical data, directly comparing physiological findings to perceptual capabilities. Because these subjects showed deficits in motion discrimination, we focused on area MT/V5, which plays a central role in motion processing. Most neurons in normal MT respond equally to visual stimuli presented through either eye; most recorded in amblyopes strongly preferred stimulation of the non-amblyopic (fellow) eye. The pooled responses of neurons driven by the amblyopic eye showed reduced sensitivity to coherent motion, and preferred higher speeds, in agreement with behavioral measurements. MT neurons were more limited in their capacity to integrate motion information over time than expected from behavioral performance; neurons driven by the amblyopic eye had even shorter integration times than those driven by the fellow eye. We conclude that some, but not all, of the motion sensitivity deficits associated with amblyopia can be explained by abnormal development of MT.