STRUCTURAL BASIS OF AMBLYOPIA IN MONKEYS & HUMANS

猴子弱视的结构基础

• 批准号: 6277969
• 负责人: JONATHAN C HORTON
• 金额: $ 5.21万
• 依托单位: UNIVERSITY OF CALIFORNIA AT DAVIS
• 依托单位国家: 美国
• 财政年份: 1998
• 资助国家: 美国
• 起止时间: 1998-05-01 至 1999-04-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6277969
• 关键词: Mammalia; Primates; ear; surgery

Significance Amblyopia (lazy eye) causes visual loss in 2% of the American population. Our research is directed at elucidating structural changes in the primate visual cortex which occur from visual deprivation. Objectives Visual deprivation induced by monocular eyelid suture, a laboratory model for congenital cataract, results in shrinkage of ocular dominance columns serving the closed eye. We performed monocular suture in macaques at ages 1,3,5,7, and 12 weeks to define the critical period for plasticity of ocular dominance columns. Results After a minimum survival of 8 months, complete montages of [3H]proline-labelled columns were reconstructed from flat-mounts of striate cortex in both hemispheres. Visual deprivation induced the columns throughout V1 to retract the same distance from their original borders in layer IVc(. At the earliest age we tested (1 week), visual deprivation reduced the columns to fragments. These fragments always coincided with a cytochrome oxidase patch, or a short string of patches, in the upper layers. More severe column shrinkage occurred in layer IVc( (parvo) than layer IVca (magno). The geniculate input to the patches in layer III (konio) appeared normal after deprivation, despite loss of CO activity. Surprisingly, the blind spot representation of the open eye was shrunken by monocular deprivation, although binocular competition is absent in this region. We found that eyelid suture at age 1 week caused the most severe column shrinkage. With suture at later ages, the degree of column shrinkage showed a progressive decline. This implies that primate visual cortex is most vulnerable to deprivation during the first weeks of life, and should provide further impetus for treatment of children with congenital cataract at the earliest possible age. Future Directions Analysis of the changes in connections between cortical layers which occur in amblyopia and initiation of new studies regarding the cortical basis of strabismus (crossed eyes). KEYWORDS ocular dominance column, critical period, amblyopia, visual deprivation, cytochrome oxidase patch, flat-mount, striate cortex, strabismus

弱视的重要性（弱视）导致2%的 美国人口。 我们的研究旨在阐明 灵长类视觉皮层的结构变化， 视觉剥夺 目的： 单眼眼睑缝合，先天性白内障的实验室模型， 导致眼优势柱收缩， 眼睛 我们在1岁、3岁、5岁、7岁和8岁时对猕猴进行了单眼缝合， 12周确定眼部可塑性的关键期 优势列 结果在最少生存8个月后， 重建[3H]脯氨酸标记柱的完整蒙太奇 从两个半球的纹状皮质的平面上。 视觉 剥夺诱导整个V1的列缩回相同的 与它们在层IVc中的原始边界的距离（. 尽早 年龄，我们测试（1周），视觉剥夺减少列， 片段 这些片段总是与细胞色素氧化酶相吻合 一小块或一小串的小块。 更严重 柱收缩发生在IVc层（比IVca层小 （magno）. 膝状体对第三层斑块的输入（konio） 在剥夺后，尽管CO活性丧失，但表现正常。 令人惊讶的是，睁开眼睛的盲点表示是 由于单眼剥夺而缩小，尽管双眼竞争是 在这个地区缺席。 我们发现，眼睑缝合在1周龄 导致了最严重的柱收缩。 随着年龄的增长， 柱体收缩程度呈递减趋势。 这 这意味着灵长类动物的视觉皮层最容易受到剥夺 在生命的最初几周，并应提供进一步的动力， 儿童先天性白内障的早期治疗 可能的年龄 未来的方向 在弱视中发生的皮层之间的联系， 关于斜视的皮质基础的新研究的开始 （交叉的眼睛）。 关键词眼优势柱，关键期， 弱视，视觉剥夺，细胞色素氧化酶贴片，平贴， 纹状皮质，斜视