Department of Human Anatomy and Neurobiology, Xiangya Medical College of Central South University, Changsha 410013, Hunan Province, China ; Department of Human Anatomy, University of South China, Hengyang 421001, Hunan Province, China.
Department of Human Anatomy, University of South China, Hengyang 421001, Hunan Province, China.
Neural Regen Res. 2012 Jan 5;7(1):18-23. doi: 10.3969/j.issn.1673-5374.2012.01.003.
The present study examined changes in retinal tyrosine hydroxylase (TH) expression in rats having undergone optic nerve transection and housed under a normal day/night cycle or in the dark. The aim was to investigate the effects of amacrine cells on axonal regeneration in retinal ganglion cells and on the synapses that transmit visual signals. The results revealed that retinal TH expression gradually decreased following optic nerve transection in rats housed under a normal day/night cycle, reaching a minimum at 5 days. In contrast, retinal TH expression decreased to a minimum at 1 day following optic nerve transection in dark reared rats, gradually increasing afterward and reaching a normal level at 5-7 days. The number of TH-positive synaptic particles correlated with the TH levels, indicating that dark rearing can help maintain TH expression during the synaptic degeneration stage (5-7 days after optic nerve injury) in retinal amacrine cells.
本研究观察了在正常昼夜循环或黑暗环境下经历视神经切断的大鼠视网膜酪氨酸羟化酶 (TH) 表达的变化。目的是研究无长突细胞对视网膜神经节细胞轴突再生和传递视觉信号的突触的影响。结果表明，在正常昼夜循环环境下饲养的大鼠视神经切断后，视网膜 TH 表达逐渐下降，在 5 天时达到最低。相比之下，在黑暗饲养的大鼠中，视神经切断后 1 天视网膜 TH 表达降至最低，随后逐渐增加，在 5-7 天达到正常水平。TH 阳性突触颗粒的数量与 TH 水平相关，表明黑暗饲养可以帮助维持视网膜无长突细胞在突触退化阶段（视神经损伤后 5-7 天）的 TH 表达。
