NEURONAL PLASTICITY IN THE RETINA

描述(改编自申请者摘要)：本项目旨在 了解兔视网膜神经元回路如何改变或适应 昼夜节律振荡器。生物钟或振荡器具有一定的节律性。 在没有外部计时提示的情况下大约24小时。循环 环境刺激，如光，可以缠绕生物钟。这 该项目将确定生物钟是否调节水平锥体 表现出昼夜节律的细胞。主要的光感受器输入到 适应黑暗的锥形水平细胞表现出昼夜节律；锥形输入 白天占主导地位，夜间占主导地位。一个 电生理、神经化学和解剖学技术的结合 将被用来确定生物钟是否参与 水平细胞和神经节细胞的光反应以及 水平单元间隙结耦合。将确定是否有一个 生物钟控制着多巴胺、褪黑素和腺苷的水平，因为 以及胞外pH。然后将确定昼夜节律是否 时钟使用这些信号机制中的任何一种来调节光响应 水平细胞和神经节细胞。测量将持续进行 过度融合的视网膜眼罩中的黑暗(没有计时线索) 准备工作。生物钟的紊乱可能会导致视网膜 光感受器退化。因此，增加了对昼夜节律的理解 时钟过程将有助于理解人类的视网膜过程和 功能障碍。这些研究也可能为药物治疗提供依据。 视网膜疾病被认为与昼夜节律紊乱有关 流程。

DESCRIPTION (Adapted from applicant's abstract): This project seeks to understand how neuronal circuits in the rabbit retina change or adapt due to a circadian oscillator. A circadian clock or oscillator has a rhythmicity of approximately 24 hours in the absence of external timing cues. Cyclic environmental stimuli such as light can entrain the circadian clock. This project will determine whether a circadian clock regulates cone-horizontal cells that exhibit a diurnal rhythm. The dominant photoreceptor input to dark-adapted, cone horizontal cells exhibits a diurnal rhythm; cone inputs predominate during the day and rod inputs predominate during the night. A combination of electrophysiological, neurochemical and anatomical techniques will be utilized to determine whether a circadian clock is involved in horizontal cell and ganglion cell light responsiveness, as well as horizontal cell gap junctional coupling. It will be determined whether a circadian clock controls the levels of dopamine, melatonin and adenosine, as well as extracellular pH. It will then be determined whether the circadian clock uses any of these signaling mechanisms to regulate the light responses of horizontal and ganglion cells. Measurements will be made in constant darkness (absence of timing cues) in a superfused, retinal eyecup preparation. Disruption of the circadian clock may result in retinal photoreceptor degeneration. Thus, increased understanding of the circadian clock processes will aid in the understanding of human retinal processes and dysfunction. These studies may also provide the basis for drug therapy for retinal disorders thought to be linked to the disruption of circadian processes.