Neuronal Correlates of Amblyopia in the Visual Cortex of Macaque Monkeys with Experimental Strabismus and Anisometropia
Neuronal Correlates of Amblyopia in the Visual Cortex of Macaque Monkeys with Experimental Strabismus and Anisometropia
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DOI：
10.1523/jneurosci.18-16-06411.1998
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发表时间：
1998-08
期刊：
影响因子：
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通讯作者：
L. Kiorpes;D. Kiper;Lawrence P O 'keefe;J. Cavanaugh;J. Movshon;Allen Siegel;Michael Gorman;
中科院分区：
文献类型：
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作者：
L. Kiorpes;D. Kiper;Lawrence P O 'keefe;J. Cavanaugh;J. Movshon;Allen Siegel;Michael Gorman;
弱视是一种图形视觉发育障碍。猕猴在出生后的头几周通过手术造成内斜视，或在出生后的头几个月内在一只眼睛戴上-10屈光度的隐形眼镜以模拟屈光参差，通常会发展为弱视。我们研究了6只弱视猕猴的视皮层神经元的反应特性，其中3只为屈光参差，3只为斜视。在所有猴子中，皮质双眼性都减少了。在屈光参差者中，弱视眼影响相对较小比例的皮质神经元;在斜视者中，双眼的影响更接近相等。弱视的严重程度与弱视眼对皮质的输入相对强度有关，仅对于受影响更严重的弱视者。皮质神经元的空间频率调谐和对比敏感度的测量结果显示，三个不太严重的弱视眼（两个斜视和屈光参差）之间的差异不大。在三个更严重的受影响的动物（一个斜视和两个屈光参差），最佳的空间频率和空间分辨率的皮质神经元驱动的弱视眼大大低于非弱视眼驱动的神经元。两眼之间的神经元对比敏感度没有可靠的差异。从代表周边视野的皮层记录的神经元样本显示没有眼间差异，这表明弱视的影响在皮层的部分subserving中心凹视觉中更为明显。视皮层神经元的眼优势和空间特性的质量、异常与弱视的深度有关。然而，定量分析表明，这些异常本身并不能解释弱视的全部视觉缺陷。对纹外皮质区的研究可能会发现更多的异常，从而解释这些缺陷。
Amblyopia is a developmental disorder of pattern vision. After surgical creation of esotropic strabismus in the first weeks of life or after wearing −10 diopter contact lenses in one eye to simulate anisometropia during the first months of life, macaques often develop amblyopia. We studied the response properties of visual cortex neurons in six amblyopic macaques; three monkeys were anisometropic, and three were strabismic. In all monkeys, cortical binocularity was reduced. In anisometropes, the amblyopic eye influenced a relatively small proportion of cortical neurons; in strabismics, the influence of the two eyes was more nearly equal. The severity of amblyopia was related to the relative strength of the input of the amblyopic eye to the cortex only for the more seriously affected amblyopes. Measurements of the spatial frequency tuning and contrast sensitivity of cortical neurons showed few differences between the eyes for the three less severe amblyopes (two strabismic and one anisometropic). In the three more severely affected animals (one strabismic and two anisometropic), the optimal spatial frequency and spatial resolution of cortical neurons driven by the amblyopic eye were substantially and significantly lower than for neurons driven by the nonamblyopic eye. There were no reliable differences in neuronal contrast sensitivity between the eyes. A sample of neurons recorded from cortex representing the peripheral visual field showed no interocular differences, suggesting that the effects of amblyopia were more pronounced in portions of the cortex subserving foveal vision. Qualitatively, abnormalities in both the eye dominance and spatial properties of visual cortex neurons were related on a case-by-case basis to the depth of amblyopia. Quantitative analysis suggests, however, that these abnormalities alone do not explain the full range of visual deficits in amblyopia. Studies of extrastriate cortical areas may uncover further abnormalities that explain these deficits.