...
  • 主题
高级搜索  >
历史搜索 清空历史
首页> 外文期刊>The European Journal of Neuroscience >Loss of photic entrainment at low illuminances in rats with acute photoreceptor degeneration.
【24h】

Loss of photic entrainment at low illuminances in rats with acute photoreceptor degeneration.

机译：急性光感受器变性大鼠低照度下光合带的丧失。

获取原文
获取原文并翻译 | 示例
           
页面导航
  • 摘要
  • 著录项
  • 相似文献
  • 相关主题

摘要

In several species, an acute injection of N-methyl-N-nitrosourea (MNU) induces a retinal degeneration characterized principally by a rapid loss of the outer nuclear layer, the other layers remaining structurally intact. It has, however, also been reported that down-regulation of melanopsin gene expression is associated with the degeneration and is detectable soon after injection. Melanopsin is expressed by a small subset of intrinsically photosensitive retinal ganglion cells and plays an important role in circadian behaviour photoentrainment. We injected MNU into Long Evans rats and investigated the ability of animals to entrain to three light/dark cycles of different light intensities (300, 15 and 1 lux). Control animals entrained their locomotor activity rhythms to the three cycles. In contrast, MNU-treated animals could only entrain properly to the 300 lux cycle. For the 15 lux cycle, their phase angle was much altered compared with control animals, and for the 1 lux cycle, MNU-injected animals were unable to photoentrain and exhibited an apparent free-run activity pattern with a period of 24.3 h. Subsequent to behavioural studies the animals were killed and rod, cone, melanopsin expression and melanopsin-expressing cells were quantified. Rod and cone loss was almost complete, melanopsin protein was reduced by 83% and melanopsin-expressing cells were reduced by 37%. Our study provides a comprehensive model of photoreceptor degeneration at the adult stage and a simple and versatile method to investigate the relation between retinal photoreceptors and the circadian system.
机译：在几个物种中，急性注射N-甲基-N-亚硝基脲（MNU）会引起视网膜变性，其主要特征是外核层迅速丧失，其他层保持结构完整。但是，也有报道说，黑素蛋白基因表达的下调与变性有关，注射后不久就可以检测到。黑素菌素由一小部分固有的光敏性视网膜神经节细胞表达，并且在昼夜节律行为光夹带中起重要作用。我们将MNU注射到Long Evans大鼠中，并研究了动物携带三种不同光强度（300、15和1 lux）的明/暗周期的能力。对照动物将其运动活动节律带入三个周期。相比之下，经MNU处理的动物只能正确地进入300勒克斯循环。与对照动物相比，在15 lux循环中，它们的相角发生了很大变化，而在1 lux循环中，注射MNU的动物无法进行光en带，并且在24.3 h的时间内表现出明显的自由运转活动模式。进行行为研究后，处死动物并定量杆，视锥细胞，黑色素表达和表达黑色素的细胞。视杆和视锥细胞丧失几乎完全，黑色素蛋白减少了83％，表达黑色素的细胞减少了37％。我们的研究提供了成年阶段光感受器变性的综合模型，以及研究视网膜光感受器与昼夜节律系统之间关系的简单通用方法。

著录项

相似文献

  • 外文文献
  • 中文文献
  • 专利
获取原文

客服邮箱：kefu@zhangqiaokeyan.com

京公网安备：11010802029741号 ICP备案号：京ICP备15016152号-6 六维联合信息科技 (北京) 有限公司©版权所有

  • 客服微信

  • 服务号