Baburina E A, Beltadze N T
Ontogenez. 1983 Sep-Oct;14(5):453-76.
The external photoreceptor segments in the retina of vertebrates have been studied already more than 100 years; the intensity of these studies increased markedly during the recent 20 years due to the introduction of autoradiography and electron microscopy. These methods allowed to study the ultrastructure of external segments of the rods and cones in many vertebrate species, its development in ontogenesis, the renewal of external segments and the dependence of renewal on the diurnal rhythm of illumination. All these data have never been summed up and discussed. This review provides a general picture of studies of different aspects of the ultrastructure of external segments; the models of formation of the external segments' discs proposed by several authors are considered; the necessity of continuation and widening of comparative studies of the ultrastructure of external photoreceptor segments in different vertebrates is founded. The most important conclusions concern the differences between the rods and the cones during renewal of the membranes discs of external segments.
脊椎动物视网膜中的外部光感受器节段已经被研究了100多年；由于放射自显影术和电子显微镜技术的引入，在最近20年里这些研究的强度显著增加。这些方法使得研究许多脊椎动物物种中视杆和视锥外部节段的超微结构、其在个体发育中的发育、外部节段的更新以及更新对照明昼夜节律的依赖性成为可能。所有这些数据从未被总结和讨论过。这篇综述提供了外部节段超微结构不同方面研究的总体情况；考虑了几位作者提出的外部节段盘形成模型；确立了继续并拓宽不同脊椎动物外部光感受器节段超微结构比较研究的必要性。最重要的结论涉及外部节段膜盘更新过程中视杆和视锥之间的差异。
