Križaj David, Huang Wei, Furukawa Takahisa, Punzo Claudio, Xing Wei
Department of Ophthalmology & Visual Sciences, John A. Moran Eye Center, Salt Lake City, UT 84132, United States.
Vision Res. 2010 Nov 23;50(23):2460-5. doi: 10.1016/j.visres.2010.08.034. Epub 2010 Aug 27.
The light response in retinal ON bipolar cells is associated with disinhibition of current flow through cation channels recently identified as type 1 members of the melastatin transient receptor potential (TRPM) family. We determined the developmental expression of Trpm1 in the wild type C57BL/6, DBA/2J, DBA2J-Gpnmb mouse retinas and in Pde6brd1 retinas characterized by degeneration of rod photoreceptors. Trpm1 mRNA in wild type retinas was low at birth but exhibited progressive increases in abundance up to early adulthood at postnatal day 21 (P21). Retinal Trpm1 mRNA content did not decrease following loss of photoreceptors. At P21, TRPM1-immunopositive perikarya migrated into the outer nuclear layer. The TRPM1 protein was trafficked to discrete postsynaptic puncta in wild type retinas whereas in adult Pde6brd1 mouse retinas, TRPM1 translocated to bipolar perikarya and bar-like structures in the distal inner nuclear layer. These findings show that expression and localization of the TRPM1 in the mouse retina is plastic, modulated by use-dependence and availability of sustained excitatory input.
视网膜ON双极细胞中的光反应与通过最近被鉴定为褪黑素瞬时受体电位（TRPM）家族1型成员的阳离子通道的电流去抑制有关。我们确定了Trpm1在野生型C57BL/6、DBA/2J、DBA2J-Gpnmb小鼠视网膜以及以视杆光感受器退化为特征的Pde6brd1视网膜中的发育表达。野生型视网膜中的Trpm1 mRNA在出生时较低，但在出生后第21天（P21）直至成年早期，其丰度逐渐增加。光感受器丧失后，视网膜Trpm1 mRNA含量并未降低。在P21时，TRPM1免疫阳性的胞体迁移到外核层。TRPM1蛋白在野生型视网膜中被运输到离散的突触后小点，而在成年Pde6brd1小鼠视网膜中，TRPM1转移到双极胞体和远端内核层的棒状结构中。这些发现表明，TRPM1在小鼠视网膜中的表达和定位具有可塑性，受使用依赖性和持续兴奋性输入的可用性调节。
