Fitzgerald K M, Cibis G W, Giambrone S A, Harris D J
Vision Sciences Laboratory, Children's Mercy Hospital, Kansas City, Missouri 64108.
J Clin Invest. 1994 Jun;93(6):2425-30. doi: 10.1172/JCI117250.
There have been reports of abnormal retinal neurotransmission determined by electroretinography in boys with Duchenne and Becker muscular dystrophy. Dystrophin may play a role in transmitting signals between photoreceptors and the excitatory synapse of the ON-bipolar cell. These electroretinographic changes appeared to be limited to the rod ON-pathway but we felt there was also similar abnormality in the cone ON-pathway. We used long-duration stimuli to separate ON-(depolarizing bipolar cell) and OFF (hyperpolarizing bipolar cell) contributions to the cone-dominated ERG to better understand how the retina functions in boys with Duchenne muscular dystrophy. We recorded the electroretinograms of 11 boys with Duchenne muscular dystrophy and found abnormal signal transmission at the level of the photoreceptor and ON-bipolar cell in both the rod and cone generated responses. The OFF-bipolar cell that responds to the offset of the stimulus continues to function normally. The results support our hypothesis that retinal dystrophin plays a role in receptor function or controlling ion channels at the level of the photoreceptor and depolarizing bipolar cell.
有报告称，通过视网膜电图测定，杜兴氏和贝克氏肌肉营养不良症男孩存在视网膜神经传递异常。肌营养不良蛋白可能在光感受器与视锥双极细胞的兴奋性突触之间传递信号中发挥作用。这些视网膜电图变化似乎仅限于视杆细胞的ON通路，但我们认为视锥细胞的ON通路也存在类似异常。我们使用长时间刺激来区分视锥细胞主导的视网膜电图中ON（去极化双极细胞）和OFF（超极化双极细胞）的贡献，以更好地了解杜兴氏肌肉营养不良症男孩的视网膜功能。我们记录了11名杜兴氏肌肉营养不良症男孩的视网膜电图，发现在视杆细胞和视锥细胞产生的反应中，光感受器和ON双极细胞水平存在异常信号传递。对刺激偏移作出反应的OFF双极细胞仍正常发挥功能。这些结果支持了我们的假设，即视网膜肌营养不良蛋白在光感受器和去极化双极细胞水平的受体功能或控制离子通道方面发挥作用。
