V1 to V2 Projections in Normal Vision and Amblyopia

正常视力和弱视的 V1 到 V2 投影

• 批准号: 6406452
• 负责人: LAWRENCE C SINCICH
• 金额: $ 4.02万
• 依托单位: UNIVERSITY OF CALIFORNIA, SAN FRANCISCO
• 依托单位国家: 美国
• 财政年份: 2001
• 资助国家: 美国
• 起止时间: 2001-08-01 至
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/6406452
• 关键词: Macaca; amblyopia; autoradiography; behavioral /social science research tag; brain mapping; cell population study; cytochrome oxidase; enzyme activity; eye coordination disorder; neural information processing; neuroanatomy; radiotracer; sensory deprivation; visual cortex; visual perception

In primates, visual information passes from the primary visual area (V1) to the second visual area (V2) before distribution to higher cortical areas. An accurate description of the projections linking V 1 and V2 is crucial for understanding how the brain deciphers visual images. Prior studies have shown that V2 is partitioned into three compartments, known as pale, thin, and thick stripes, defined by their content of a metabolic enzyme called cytochrome oxidase (CO). Our principal goal is to describe the anatomical projections from V1 to each V2 stripe compartment. In Specific Aim #1 we will make injections of a retrograde tracer into single CO stripes in V2 of normal macaques. The resulting pattern of labeled cells in V1 will be correlated with the V2 stripe that received the injection. Our preliminary data indicate that, contrary to a previous report, layer 4B and interblobs both project to thick stripes and pale stripes. In Specific Aim #2 we will make paired injections of two different tracers into adjacent thick stripes and pale stripes to determine if different subpopulations of cells in layer 4B and interblobs project to these V2 compartments. In Specific Aim #3 we will make injections of [3H]proline into V1 to correlate patches of efferent projections with CO staining patterns in V2. In Specific Ai/s #4 we will examine the V1->V2 projections in animals raised with early monocular deprivation. These experiments will advance our knowledge of the mechanisms underlying amblyopia, an important cause of visual loss that affects 2% of the American population. We hypothesize that a selective loss of V1->V2 projections emanating from the ocular dominance columns serving the deprived eye contributes to the loss of vision in amblyopia.

在灵长类动物中，视觉信息从主要视觉区域（V1）传递到第二视觉区域（V2），然后分发到更高的皮质区域。链接v 1和v2的投影的准确描述对于理解大脑如何解解视觉图像至关重要。先前的研究表明，V2分为三个隔室，称为苍白，薄和厚的条纹，这些条纹由它们的代谢酶的含量定义，称为细胞色素氧化酶（CO）。我们的主要目标是描述从V1到每个V2条纹隔室的解剖学预测。在特定的目标＃1中，我们将在正常猕猴的V2中注射逆行示踪剂。 V1中标记的细胞的产生模式将与接受注射的V2条纹相关。我们的初步数据表明，与先前的报告相反，第4B层和群体都将项目与厚条纹和浅色条纹相互键。在特定的目标＃2中，我们将对相邻的厚条纹和浅层条纹进行配对，以确定第4B层和Interblobs中的细胞的不同亚群项目对这些V2隔室的投影。在特定的目标＃3中，我们将[3H]脯氨酸注入V1中，以将传出投影的斑块与V2中的CO染色模式相关联。在特定的AI/S＃4中，我们将研究以早期剥夺提出的动物的V1-> V2投影。这些实验将提高我们对弱视潜在机制的了解，这是影响美国人群2％的视觉丧失的重要原因。我们假设，从剥夺眼睛的眼睛优势柱中产生的V1-> V2投影的选择性损失有助于弱视的视力丧失。