Nadal-Nicolás F M, Valiente-Soriano F J, Salinas-Navarro M, Jiménez-López M, Vidal-Sanz M, Agudo-Barriuso M
Instituto Murciano de Investigación Biosanitaria Hospital Virgen de la Arrixaca (IMIB-Virgen de la Arrixaca), Murcia, Spain; Departamento de Oftalmología, Facultad de Medicina, Universidad de Murcia, Murcia, Spain.
Instituto Murciano de Investigación Biosanitaria Hospital Virgen de la Arrixaca (IMIB-Virgen de la Arrixaca), Murcia, Spain; Departamento de Oftalmología, Facultad de Medicina, Universidad de Murcia, Murcia, Spain.
Exp Eye Res. 2015 May;134:47-52. doi: 10.1016/j.exer.2015.03.015. Epub 2015 Mar 20.
Identification of retino-retinal projecting RGCs (ret-ret RGCs) has been accomplished by tracing RGCs in one retina after intravitreal injection of different tracers in the other eye. In mammals, rabbit and rat, ret-ret RGCs are scarce and more abundant in newborn than in adult animals. To our knowledge, ret-ret RGCs have not been studied in mice. Here we purpose to revisit the presence of ret-ret RGCs in juvenile and young adult rats and mice by using retrograde tracers applied to the contralateral optic nerve instead of intravitreally. In P20 (juvenile) and P60 (young adult) animals, the left optic nerve was intraorbitally transected and Fluorogold (rats) or its analogue OHSt (mice) were applied onto its distal stump. P20 animals were sacrificed 3 (mice) or 5 (rats) days later and adult animals at 5 (mice) or 7 (rats) days. Right retinas were dissected as flat-mounts and double immunodetected for Brn3a and melanopsin. Ret-ret RGCs were those with tracer accumulation in their somas. Out of them some expressed Brn3a and/or melanopsin, while other were negative for both markers. In young adult rats, we found 2 ret-ret RGCs displaced to the inner nuclear layer. In both species, ret-ret RGCs are quite scarce and found predominantly in the nasal retina. In juvenile animals there are significantly more ret-ret RGCs (9 ± 3, rats, 13 ± 3 mice) than in young adult ones (5 ± 6 rats, 7 ± 3 mice). Finally, juvenile and young adult mice have more ret-ret RGCs than rats.
通过在一只眼睛玻璃体内注射不同示踪剂后追踪另一只视网膜中的视网膜神经节细胞（RGCs），已实现对视网膜-视网膜投射RGCs（ret-ret RGCs）的鉴定。在哺乳动物中，兔子和大鼠的ret-ret RGCs稀少，且新生动物中的数量比成年动物更多。据我们所知，尚未在小鼠中对ret-ret RGCs进行研究。在这里，我们旨在通过将逆行示踪剂应用于对侧视神经而非玻璃体内，重新研究幼年和年轻成年大鼠及小鼠中ret-ret RGCs的存在情况。在出生后20天（幼年）和出生后60天（年轻成年）的动物中，将左侧视神经眶内横断，并将荧光金（大鼠）或其类似物OHSt（小鼠）应用于其远端残端。出生后20天的动物在3天（小鼠）或5天（大鼠）后处死，成年动物在5天（小鼠）或7天（大鼠）后处死。将右侧视网膜制成平铺标本，并对Brn3a和黑视蛋白进行双重免疫检测。ret-ret RGCs是那些在其胞体中有示踪剂积累的细胞。其中一些表达Brn3a和/或黑视蛋白，而另一些则这两种标记物均为阴性。在年轻成年大鼠中，我们发现2个ret-ret RGCs移位至内核层。在这两个物种中，ret-ret RGCs都相当稀少，且主要存在于鼻侧视网膜。在幼年动物中，ret-ret RGCs（大鼠9±3个，小鼠13±3个）明显多于年轻成年动物（大鼠5±6个，小鼠7±3个）。最后，幼年和年轻成年小鼠中的ret-ret RGCs比大鼠更多。
