STUDIES ON DISK RENEWAL IN RETINAL VISUAL CELLS

光感受器的功能依赖于维持一个微妙的平衡， 光敏膜的组装过程及其降解过程。 这些过程在脊椎动物视网膜中以有节奏的方式发生， 了解控制节奏的因素可能对 了解光感受器的病理过程 我们的目标是 了解感光细胞周期代谢的调节。 的 要研究的过程是视杆细胞盘脱落，锥细胞 视网膜运动和节律性褪黑激素代谢。 每个进程 在其活动和主要模型中表现出昼夜节律性 在这些研究中使用，非洲爪蟾，可以在一个详细的研究， 体外制备，可用于实验操作。 一个主要目标 是探索“褪黑激素样”化合物的形成机制， 视网膜多巴胺分别作为黑暗和光明的信号相互作用。 使用来自尖音蛙的体外制剂的其他研究 和实验室大鼠将被用来研究的机制， 该盘脱落由光和生物钟触发。 我们 将分析眼睛中生物钟的特性， 监测褪黑激素的昼夜释放。 这些调查将 需要使用体外培养，放射免疫测定， 神经药理学、生物化学和电生理学技术。 它 了解节律性光感受器的调节 代谢将提供一个新的基础，评估机制， 肾退行性疾病的致病性。

Photoreceptor function depends on maintenance of a delicate balance between the processes of photosensitive membrane assembly and its degradation. These processes occur in a rhythmic fashion in vertebrate retina and understanding the factors controlling rhythmicity may prove important in understanding pathological processes involving photoreceptors. Our goal is to understand the regulation of cyclic photoreceptor metabolism. The processes to be studied are rod photoreceptor disc shedding, cone retinomotor movement and rhythmic melatonin metabolism. Each process exhibits circadian rhythmicity in its activity and in the principal model used in these studies, Xenopus laevis, can be studied in detail in an in vitro preparation, accessible for experimental manipulation. A major goal is to explore the mechanisms by which "melatonin-like" copmpounds and retinal dopamine interact as signals respectively for darkness and light. Additional studies using in vitro preparations derived from Rana pipiens and from laboratory rats will be used to investigate the mechanisms by which disc shedding is triggered by light and by a circadian clock. We will analyze the properties of a circadian clock localized in the eye by monitoring circadian release of melatonin. These investigations will require the use of in vitro culture, radioimmunoassay, neuropharmacological, biochemical and electrophysiological techniques. It is expected that understanding regulation of rhythmic photoreceptor metabolism will provide a new basis for evaluating mechanisms of pathogenicity in reinal degenerative diseases.