婴儿视杆光反应的恢复

Recovery of the rod photoresponse in infants.

作者信息

Hansen Ronald M, Fulton Anne B

机构信息

Department of Ophthalmology, Children's Hospital and Harvard Medical School, Boston, Massachusetts 02115, USA.

出版信息

Invest Ophthalmol Vis Sci. 2005 Feb;46(2):764-8. doi: 10.1167/iovs.04-0257.

DOI:10.1167/iovs.04-0257

PMID:15671311

Abstract

PURPOSE

To study deactivation of the rod photoresponse in infants using a paired-flash procedure. Rhodopsin content increases and scales the parameters of the activation of rod phototransduction as rods develop. However, little is known about the kinetics of deactivation in the rods of young infants.

METHODS

ERG responses to pairs of flashes were used to study the recovery of the rod response in 4- and 10-week-old infants and mature control subjects. The amplitudes of rod isolated a-wave responses to a probe flash (+3.3 log scot td . s) presented 2 to 120 seconds after an equal-intensity test flash were measured. The interstimulus interval (ISI) at which the amplitude was half that of the response to the probe flash alone (t(50)) was determined by linear interpolation.

RESULTS

Recovery time (t(50)) was significantly longer in infants than in adults (F = 18.9, df 2, 32; P < 0.01). The shape of the recovery function did not vary with age. The t(50) values were inversely proportional to the parameters of activation of rod phototransduction.

CONCLUSIONS

These results are evidence that the kinetics of deactivation in infants are slower and may be set by the proportion of rhodopsin isomerized.

摘要

目的

使用配对闪光程序研究婴儿视杆光反应的失活情况。随着视杆细胞的发育，视紫红质含量增加并调节视杆光转导激活的参数。然而，对于幼儿视杆细胞失活的动力学了解甚少。

方法

使用视网膜电图（ERG）对配对闪光的反应来研究4周和10周龄婴儿以及成熟对照受试者视杆反应的恢复情况。测量在等强度测试闪光后2至120秒出现的对探测闪光（+3.3 log scot td·s）的视杆分离a波反应的幅度。通过线性插值确定幅度为单独对探测闪光反应幅度一半时的刺激间隔（ISI）（t(50)）。