DEVELOPMENT OF ROD FUNCTION

本应用建议研究正常人体杆状物的发育 功能。这些棒将光转换成电信号，因此 启动视觉。杆状光传导过程的不成熟可能 比以前更多地解释了人类暗视的不成熟 被认可了。 申请人讨论的证据是，与成人相比，婴儿的棒子 外节较短，视紫红质浓度较低 外节的圆盘。这些证据导致了预测 信号的饱和(最大)幅度和放大(或增益) 杆状光响应会随着发育而增加，但 对于扩增来说，发育增长将会较慢。此外， 后极区杆状结构发育迟缓 占视网膜总面积的5%至10%，以及 预测解释后遗症的不同发展过程 极敏感度与外周敏感度；预期后极敏感度 增长得更慢。 视网膜电(ERG)a波与心理物理的研究 婴幼儿和成人对照受试者的阈值和视紫红质 用来检验这些假说。后受体部成分(b波； 暗适应阈值反应)的ERG将评估发展 视杆细胞的流动通过视网膜传递信息。 这些实验将产生新的知识，将推动我们的 理解正常的人类视觉能力的发展。什么时候 这一信息将应用于未来的儿科患者，这是可望的 揭示杆状细胞病的发病机制，有助于设计 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.