Dreher B, Barker D A, Bath M R, Keay K A
Department of Anatomy and Histology, University of Sydney, N.S.W., Australia.
J Comp Neurol. 1996 Dec 9;376(2):223-40. doi: 10.1002/(SICI)1096-9861(19961209)376:2<223::AID-CNE5>3.0.CO;2-5.
Using an antibody against calbindin-28kD, we have studied the spatial pattern of expression of this protein in the superior colliculi (SC) of four strains of mature laboratory rats. In all four strains, calbindin-expressing cells (CECs) formed horizontally oriented tiers in the retinorecipient and intermediate gray layers but were diffusely distributed throughout the deep layers. Ontogenetically, calbindin-28kD was expressed for the first time in the retinorecipient layers at postconceptional day 20 (PCD 20), by cells located in the rostrolateral region where the first born retinal ganglion cells (RGCs) are represented. Although on the day of birth (PCD 22/23), the CECs were distributed more widely, they were still absent in the most medial part of the SC, that is, the region where the latest born RGCs are represented. The spatial distribution of CECs became adultlike only by PCD 29, that is, at the end of the period of the naturally occurring death of the RGCs. Monocular eye enucleations on PCD 23 prevented the expression of calbindin in the medial fifth of the retinorecipient layers of the contralateral SC, while the unilateral removal of the visual cortices had no discernable effect on the numbers and distribution of the CECs in either SC. Thus, the spatiotemporal pattern of ontogenetic expression of calbindin-28kD in the retinorecipient layers of SC reflects the spatiotemporal pattern of generation of the RGCs, and the retinal input appears to induce neuronal expression of calbindin-28kD in these layers.
利用抗钙结合蛋白-28kD抗体，我们研究了该蛋白在四种成熟实验大鼠品系上丘（SC）中的表达空间模式。在所有四个品系中，表达钙结合蛋白的细胞（CECs）在视网膜接受层和中间灰质层中形成水平方向的层，但在深层中分布较为分散。在个体发育过程中，钙结合蛋白-28kD在受孕后第20天（PCD 20）首次在视网膜接受层中表达，由位于 rostrolateral 区域的细胞表达，该区域代表最早出生的视网膜神经节细胞（RGCs）。尽管在出生日（PCD 22/23），CECs 的分布更广泛，但在上丘最内侧部分，即代表最晚出生的RGCs的区域，仍然没有CECs。CECs 的空间分布直到PCD 29才变得像成年个体，也就是在RGCs自然死亡期结束时。在PCD 23进行单眼摘除术可阻止对侧SC视网膜接受层内侧五分之一区域中钙结合蛋白的表达，而单侧切除视觉皮层对任一SC中CECs的数量和分布均无明显影响。因此，SC视网膜接受层中钙结合蛋白-28kD个体发育表达的时空模式反映了RGCs产生的时空模式，并且视网膜输入似乎诱导了这些层中钙结合蛋白-28kD的神经元表达。
