DEVELOPMENT OF ROD FUNCTION

本申请提出研究正常人杆的发育 功能 这些杆将光转换成电信号， 启动视觉。 视杆细胞光转导过程的不成熟可能 比以前更多地解释了人类暗视觉的不成熟 认可. 申请人讨论的证据表明，与成人相比， 外节较短，视紫红质的浓度较低， 外节的椎间盘。 这些证据导致了这样的预测， 的饱和（最大）幅度和放大（或增益）， 视杆细胞的光反应随发育而增加， 发育增长将因扩增而减慢。另夕h 后极杆的解剖学成熟延迟， 相当于总视网膜面积的5%至10%，并且 预测可以解释不同的发展过程后， 极与外周灵敏度;预期后极灵敏度 增加得更慢。 视网膜电图（ERG）a波和心理物理学的研究 阈值在年轻的婴儿和成人对照组，和视紫红质将 用来检验这些假设。 感受器后成分（b波; 暗视阈值反应）的ERG将评估的发展， 视杆细胞通过视网膜传递信息。 这些实验将产生新的知识， 了解正常人类视觉能力的发展。 当 这些信息应用于未来的儿科患者，预计 以揭示视杆细胞疾病的机制， 新的治疗策略。

This application proposes to study the development of normal human rod function. The rods transduce light into an electrical signal and so initiate vision. Immaturities of rod phototransduction processes may explain more of the immaturities of human scotopic vision than previously recognized. The applicant discusses evidence that, compared to adults', infants' rod outer segments are shorter and the concentration of rhodopsin is lower in the discs of the outer segment. The evidence leads to predictions that both the saturated (maximum) amplitude and amplification (or gain) of the rod photoresponse will increase with development, but the rate of developmental increase will be slower for amplification. Additionally, the delayed anatomic maturation of rods at the posterior pole, an area amounting to 5% to 10% of the total retinal area, is considered, and predicted to account for differential courses of development of posterior pole vs peripheral sensitivities; posterior pole sensitivity is expected to increase more slowly. Studies of electroretinographic (ERG) a-waves and psychophysical thresholds in young infants and adult control subjects, and rhodopsin will be used to test these hypotheses. Post receptoral components (b-wave; scotopic threshold response) of the ERG will evaluate the development of the flow of rod mediated information across the retina. These experiments will generate new knowledge that will advance our understanding of the development of normal, human visual capacities. When this information is applied to future pediatric patients, it is expected to disclose mechanisms of rod cell disease and so contribute to the design of novel therapeutic strategies.