DEVELOPMENT OF PHOTORECEPTOR FUNCTION

描述（改编自研究者摘要）：广泛目的 是研究未成熟视杆和视锥中的光传导过程 人类婴儿的光感受器。 在正常足月出生的婴儿中 视网膜电图（ERG）反应的横断面研究， 全视野刺激将研究杆中的光转导失活 和视锥细胞感光器的激活。 具体而言，视杆细胞分离ERG 对成对闪光的反应将检验恢复的假设 视杆细胞反应的相位在婴儿中比成人低 对照 4、10、18周龄婴儿及成人视锥细胞的研究 控制将测试假设，即锥细胞的增益或灵敏度， 光转导比饱和的光转导具有更快的发育过程。 振幅 近中央，杆介导的出乎意料的快速发展 视觉敏感性导致的假设，即时间总和将是 偏心10度成熟，30度不成熟。 一 心理物理程序和受试者内设计将评估时间 10周龄和6月奥尔兹时10度和30度偏心率的总和 奥尔兹和成人对照组。 这项工作的长期目标， 婴儿视网膜疾病中的视网膜功能障碍和视力损害， 将继续研究前早产儿，其中一半有 非瘢痕性早产儿视网膜病变（ROP）和一半没有病史 ROP。 视网膜电图研究视杆细胞反应的激活和恢复阶段， 和视锥细胞反应将在学期后年龄进行，以检验假设 光感受器机制。 视觉的纵向测量 10度和30度偏心率的阈值将测试 假设近中心阈值具有异常缓慢的过程， 在有ROP病史的人中发展。

DESCRIPTION (Adapted from the Investigator's Abstract): the broad objective is to study phototransduction processes in the immature rod and cone photoreceptors of human infants. In normal term born infants cross-sectional studies of electroretinographic (ERG) responses to full-field stimuli will investigate phototransduction deactivation in rod and activation in cone photoreceptors. Specifically, rod isolated ERG responses to pairs of flashes will test the hypothesis that the recovery phase of the rod photoreceptor response is lower in infants than adult controls. The cone study in 4-, 10-and 18-week old infants and adult controls will test the hypothesis that the gain, or sensitivity, of cone phototransduction has a faster developmental course than does the saturated amplitude. The unexpectedly rapid development of near central, rod mediated visual sensitivity leads to the hypothesis that temporal summation will be mature at 10 degree eccentric while immature at 30 degree eccentric. A psychophysical procedure and a within subject design will assess temporal summation at 10 degree and 30 degree eccentricities in 10 week olds, 6 month olds and adult controls. The long term objective of this work, the delineation of mechanisms of retinal dysfunction and visual impairment in infantile retinal disorders, will be pursued with studies in former preterms, half with a history of non-cicatricial retinopathy of prematurity (ROP) and half with no history of ROP. ERG studies of the activation and recovery phases of the rod response, and cone responses will be conducted at post terms ages to test hypotheses about photoreceptor mechanisms. Longitudinal measures of the visual thresholds at 10 degree and 30 degree eccentricities will test the hypothesis that the near central threshold has an abnormally slow course of development in those with a history of ROP.