Altered Balance of Receptive Field Excitation and Suppression in Visual Cortex of Amblyopic Macaque Monkeys
Altered Balance of Receptive Field Excitation and Suppression in Visual Cortex of Amblyopic Macaque Monkeys
复制标题
DOI：
10.1523/jneurosci.0449-17.2017
复制
发表时间：
2017-08-23
影响因子：
5.3
通讯作者：
Kiorpes, Lynne
中科院分区：
文献类型：
--
作者：
Hallum, Luke E.;Shooner, Christopher;Kiorpes, Lynne
在弱视中，由发育期间的异常视觉体验引起的视觉障碍，弱视眼（AE）失去视觉敏感性，而对侧眼（FE）基本上不受影响。弱视患者的双眼视觉常因两眼间抑制而中断。我们使用96电极阵列记录神经元和神经元组在区域V1和V2的6名女性猕猴（猕猴nemestrina）弱视的人工斜视或屈光参差在早期的生活，以及两个视觉正常的女性对照。为了直接测量抑制性双眼相互作用，我们记录了神经元对双视刺激的反应。我们用大的正弦光栅同时刺激两只眼睛，用不同方向和空间频率的升余弦调制器独立控制它们的对比度。我们在每个皮质部位模拟每只眼睛的感受野，使用高斯包络的差异，并得出估计的中央兴奋和周围抑制的强度。我们使用这些估计分别计算眼优势的兴奋和抑制。兴奋性驱动从FE主导弱视视皮层，特别是在更严重的弱视，但抑制从FE和AE是普遍存在于所有动物。这种不平衡在深度弱视中产生了强烈的眼间抑制：AE中对比度的增加降低了双眼皮质部位的反应。这些反应模式揭示了可能导致弱视患者视力受损的眼间抑制机制。
In amblyopia, a visual disorder caused by abnormal visual experience during development, the amblyopic eye (AE) loses visual sensitivity whereas the fellow eye (FE) is largely unaffected. Binocular vision in amblyopes is often disrupted by interocular suppression. We used 96-electrode arrays to record neurons and neuronal groups in areas V1 and V2 of six female macaque monkeys (Macaca nemestrina) made amblyopic by artificial strabismus or anisometropia in early life, as well as two visually normal female controls. To measure suppressive binocular interactions directly, we recorded neuronal responses to dichoptic stimulation. We stimulated both eyes simultaneously with large sinusoidal gratings, controlling their contrast independently with raised-cosine modulators of different orientations and spatial frequencies. We modeled each eye's receptive field at each cortical site using a difference of Gaussian envelopes and derived estimates of the strength of central excitation and surround suppression. We used these estimates to calculate ocular dominance separately for excitation and suppression. Excitatory drive from the FE dominated amblyopic visual cortex, especially in more severe amblyopes, but suppression from both the FE and AEs was prevalent in all animals. This imbalance created strong interocular suppression in deep amblyopes: increasing contrast in the AE decreased responses at binocular cortical sites. These response patterns reveal mechanisms that likely contribute to the interocular suppression that disrupts vision in amblyopes.