Casini G, Rickman D W, Trasarti L, Brecha N C
Department of Environmental Sciences, Tuscia University, 01100, Viterbo, Italy.
Brain Res Dev Brain Res. 1998 Nov 1;111(1):107-17. doi: 10.1016/s0165-3806(98)00127-8.
In the adult rabbit, rat and cat retina, parvalbumin (PV) immunoreactivity is primarily localized to a population of narrow-field, bistratified amacrine cells, the AII amacrine cells-major interneurons of the rod pathway. This investigation examines the postnatal development of PV immunoreactivity in order to better understand the ontogeny of the AII amacrine cell population and the formation of the rod pathway. Rabbit retinas at various postnatal ages were processed for immunohistochemistry using a monoclonal antibody directed to PV and analyzed morphometrically. On the day of birth, PV immunoreactive cell bodies are numerous in the proximal inner nuclear layer (INL) in all retinal regions. These cells have a primary process directed towards the inner plexiform layer (IPL). At postnatal day (PND) 2, a few faint immunoreactive processes are observed in the IPL. At PND 4, well-stained processes are observed to ramify mainly in the proximal IPL. At PND 6, strongly immunoreactive processes are present in both the distal and proximal IPL, and at PND 10 they form a continuous, dense plexus in both levels of the IPL. By PND 10, the morphology of PV immunoreactive cells is similar to PV immunoreactive cells in adult retinas. The density of PV immunoreactive cells in the proximal INL increases from PND 2 to PND 5, then it gradually decreases to adult values, while the total number of PV immunoreactive cell bodies increases until PND 10. PV immunoreactive amacrine cells at PND 2, as in the adult, are nonrandomly distributed across the retinal surface. These studies show that PV immunoreactive amacrine cells have a developmental profile that is similar to several other amacrine cell types. This includes the elaboration of processes in the IPL during the first postnatal week and a mature appearance towards the end of the second week of life, about the time of eye opening. These observations indicate that the AII amacrine cell may participate in the processing of visual information at eye opening.
在成年兔、大鼠和猫的视网膜中，小清蛋白（PV）免疫反应性主要定位于一群窄场、双分层无长突细胞，即AII无长突细胞——视杆通路的主要中间神经元。本研究通过检测PV免疫反应性的产后发育情况，以更好地了解AII无长突细胞群体的个体发生以及视杆通路的形成。使用针对PV的单克隆抗体对不同产后年龄的兔视网膜进行免疫组织化学处理，并进行形态计量分析。出生当天，所有视网膜区域的近端内核层（INL）中都有大量PV免疫反应性细胞体。这些细胞有一个伸向内网状层（IPL）的初级突起。在出生后第2天（PND 2），在IPL中观察到一些微弱的免疫反应性突起。在PND 4时，观察到染色良好的突起主要在近端IPL中分支。在PND 6时，远端和近端IPL中均出现强免疫反应性突起，在PND 10时，它们在IPL的两个层面形成连续、密集的神经丛。到PND 10时，PV免疫反应性细胞的形态与成年视网膜中的PV免疫反应性细胞相似。近端INL中PV免疫反应性细胞的密度从PND 2增加到PND 5，然后逐渐降至成年水平，而PV免疫反应性细胞体的总数增加直至PND 10。与成年时一样，PND 2时的PV免疫反应性无长突细胞在视网膜表面呈非随机分布。这些研究表明，PV免疫反应性无长突细胞的发育过程与其他几种无长突细胞类型相似。这包括在出生后第一周内IPL中突起的形成，以及在出生后第二周结束时，即大约睁眼时呈现成熟外观。这些观察结果表明，AII无长突细胞可能在睁眼时参与视觉信息的处理。
