NEURONAL PLASTICITY IN THE RETINA

描述（改编自申请人的摘要）：该项目旨在 了解兔子视网膜中的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节律性 在没有外部时间线索的情况下，大约24小时。 环状 诸如光的环境刺激可以影响生物钟。 这 该项目将确定生物钟是否调节水平锥细胞 表现出昼夜节律的细胞。 占主导地位的感光细胞输入 暗适应的，视锥水平细胞表现出昼夜节律;视锥输入 在白天占主导地位，杆输入在夜间占主导地位。 一 电生理学、神经化学和解剖学技术相结合 将被用来确定是否昼夜节律钟参与 水平细胞和神经节细胞光反应，以及 水平单元间隙结耦合。 将确定是否 生物钟控制多巴胺、褪黑激素和腺苷的水平， 以及细胞外pH值。然后将确定昼夜节律是否 生物钟使用这些信号机制中的任何一种来调节光反应 水平和神经节细胞。 测量将在恒定的 灌注的视网膜眼杯中的黑暗（没有时间线索） 准备. 生物钟的紊乱可能导致视网膜病变。 光感受器变性 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视网膜过程， 功能障碍 这些研究还可能为药物治疗提供基础 被认为与昼夜节律紊乱有关的视网膜疾病 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.