DEVELOPMENT OF BINOCULAR CONNECTIONS IN PRIMATE

本研究的目的是研究 调节方向敏感性的双眼连接 刺激运动，并将特定连接的紧急情况 随着立体视觉和对称运动处理的开始。 的 该项目是基于一个良好的概念，立体视觉 依赖于方向选择神经元的正常发育 双眼视差的调节器。 核心假设是 来自于对幼猴眼球运动的观察， 偏于颞鼻运动方向， 在鼻颞方向上的移动被忽略。 我们的假设 预测由鼻视网膜输入主导的连接 在那些被来自世界各地的投入所主导的国家之前， 颞视网膜 为了验证这一预测，幼年猕猴会 首先进行视觉敏锐度、立体视觉和追踪行为检查 眼球运动 随后，动物将用于解剖追踪 实验测定：1）外侧膝状体的分离 传入纹状体4Ca层内的眼优势柱 皮质，2）从左眼和右眼的局部连接的发展 纹状皮质4B层内的柱状细胞，以及3） 来自左右眼柱4B层的条纹状皮质投射 到V2和MT的粗条纹。 这个实验性的设计可以让我们 评估几个不同地区相关连接的发展情况， 运动处理路径的水平。 记录的时间 这些连接在正常动物中的出现不仅重要， 了解立体视觉的神经解剖学共同发展， 动作灵敏度，而且还因为它将提供一个框架， 理解斜视猴和人类缺陷的原因。

The goal of the proposed research is to study the development of binocular connections that mediate sensitivity for the direction of stimulus motion, and to correlate the emergency of specific connections with the onset of stereopsis and symmetric motion processing. the project is based on the well established notion that stereoscopic vision is dependent on the normal development of direction selective neurons that are tuned for binocular disparity. The central hypothesis is derived from observations that pursuit eye movements in infant monkeys are biased for temporal-to-nasal directions of motion and that objects moving in nasal-to-temporal directions are ignored. Our hypothesis predicts that connections dominated by inputs from the nasal retina develop in advance of those that are dominated by inputs from the temporal retina. To test this prediction infant macaque monkeys will first be examined behaviorally for visual acuity, stereopsis and pursuit eye movements. Subsequently, animals will be used in anatomical tracing experiments for determining: 1) the segregation of lateral geniculate afferents into ocular dominance columns within layer 4Ca of the striate cortex, 2) the development of local connections from left and right eye columns within layer 4B of striate cortex, and 3) the development of striate cortical projections from layer 4B of left and right eye columns to thick stripes of V2 and MT. This experimental design will allow us to evaluate the development of relevant connections at several different levels of the motion processing pathway. Documenting the timing of the emergence of these connections in normal animals is important not only for understanding the neuroanatomic co-development of stereopsis and motion sensitivity, but also because it will provide a framework for understanding the cause of deficits in strabismic monkey and human.