Long Evans大鼠视网膜神经节细胞电生理学发育特性研究

Electrophysiological properties of retinal ganglion cells in Long Evans rats at different postnatal developmental stages

目的研究Long Evans大鼠不同发育阶段视网膜神经节细胞(Retinal Ganglion Cells, RGCs)电生理学特性,认识视觉发育过程中视网膜神经元成熟的细胞内机制.方法取出生后3～31 d Long Evans大鼠,制备视网膜片,寻找RGCs行膜片钳全细胞记录,给予不同强度去极化脉冲,诱发动作电位.结果 33只Long Evans大鼠共获得94个RGCs,按动作电位类型RGCs分为单锋型、瞬变型和持续型,在视觉发育不同阶段,3种类型的RGCs所占比例不同,在电生理特性上有显著差异.结论在视觉发育过程中,RGCs的电学特性逐渐成熟,动作电位的幅度、频率存在差异,提示不同类型的RGCs在编码及传递时间、空间视觉信息中具有不同作用.

Objective To investigate the electrophysiological properties of retinal ganglion cells(RGCs) in Long Evans rats during different postnatal developmental stages so as to explore the intracellular mechanism of retinal neuron maturation. Methods Whole cell patch clamp recordings of RGCs in acute retinal slices of Long Evans rats (postnatal days 3 to 31) were performed. Depolarizing current pulses of different densities were inflicted on RGCs to evoke action potentials(AP) . Results A total of 94 RGCs, single spike cells, transient and sustained cells, were acquired in 33 rats. The proportion of the three types of TGCs was different. There was significant difference in electrophysiological properties. Conclusion During the period of postnatal development, gradually matured electrophysiological properties of RGCs and differences in amplitudes and frequencies of AP suggest that different types of RGCs may play different roles in coding and transmitting spatial and temporal information.