TRANSPLANTATION STUDIES OF THE RAT VISUAL SYSTEM

拟议中的工作继续使用胚胎进行调查 啮齿类动物的视网膜移植技术 正常运作的神经回路，构成了视觉的底物， 在成熟时可以开发和修改。 通过视网膜移植物建立的连接将被详细检查 并与功能反应相关。这些回应将是 生理和行为的记录(使用瞳孔 条件反射和条件抑制范式)。除了定义 移植功能的最佳条件，我们计划使用 术后移植物连接发芽检查的准备工作 对成人宿主视觉系统的损伤。 本文提出了五项相关的研究。第一个将检查 光刺激驱动的宿主瞳孔反射的底物 视网膜移植；第二个将与生理上的 宿主大脑对移植刺激的反应性和 解剖学上的关联；第三个将检查发芽的成虫 第四项研究将研究视网膜移植能否 调节对光的条件性抑制反应 这项研究将使用多个移植来创造电路。 这项工作应该提供对最低限度的 视觉功能的基础和对 视觉系统损伤后的再生能力和可塑性 处于发展早期或成熟阶段。它还探索了 移植策略，最终可能会导致 纠正人类的视觉缺陷。

The proposed work continues an investigation using embryonic retinal transplantation techniques in rodents to examine how functioning neural circuits, that form the substrates for vision, develop and can be modified in maturity. The connections made by retinal grafts will be examined in detail and correlated with functional responses. These responses will be recorded both physiologically and behaviorally (using the pupillary reflex and a conditioned suppression paradigm). Besides defining the optimal conditions for graft function, we plan to use the preparations for examining sprouting of graft connections after injury to the adult host visual system. Five interrelated studies are proposed. The first will examine the substrates of host pupillary reflex driven by photic stimulation of a retinal transplant; the second will correlate physiological responsiveness of the host brain to transplant stimulation and the anatomical correlates; the third will examine an adult sprouting situation; the fourth will study whether a retinal transplant can mediate a conditioned suppression response to light and the fifth study will use multiple transplants to create circuits. The work should provide fundamental understanding of the minimal substrates for visual function and further insight into the regenerative and plastic capacity of the visual system after damage either early in development or at maturity. It also explores transplantation strategies that might in time lead to ways of correcting visual deficits in humans.