Jenison G, Nolte J
Cell Tissue Res. 1979 Jun 27;199(2):235-47. doi: 10.1007/BF00236135.
An electron microscopic examination of the parietal retinas of Anolis carolinensis and Iguana iguana demonstrated within each retina (1) two distinct populations of neurons, (2) two populations of glia, and (3) a population of photoreceptors which could not be subdivided. A small population of very electron-dense cells, in many respects similar to photoreceptors, was also found in the iguana. Correspondingly dark processes were found in the plexiform layer of each retina. Parietal photoreceptors generally resemble cones of the lateral eye. Glial cells were sub-classified on the basis of the location of their somata and the disposition of their processes. Neurons were identified by virtue of their cytology and their reception of axosomatic ribbon synapses from unidentified plexiform layer processes. Neuronal subtypes were located on opposite sides of the plexiform layer. Neurons distal to that layer were found to project the initial segments of their processes into the plexiform layer parallel to its long axis, while neurons central to the plexiform layer projected axons centrally and dendrites radially into the plexiform layer. The existence of at least two neuronal populations and of interphotoreceptor synapses suggests that photosensory processing within the parietal retina may be more complex than previously assumed.
对绿安乐蜥和绿鬣蜥顶叶视网膜进行的电子显微镜检查显示，每个视网膜内存在：（1）两种不同的神经元群体；（2）两种神经胶质细胞群体；（3）一群无法细分的光感受器。在鬣蜥中还发现了一小群电子密度极高的细胞，在许多方面类似于光感受器。相应地，在每个视网膜的神经丛层中都发现了颜色较深的突起。顶叶光感受器通常类似于侧眼的视锥细胞。神经胶质细胞根据其胞体位置和突起的分布进行亚分类。神经元通过其细胞学特征以及来自未识别的神经丛层突起的轴体带状突触的接受情况来识别。神经元亚型位于神经丛层的两侧。发现该层远端的神经元将其突起的起始段平行于神经丛层的长轴投射到神经丛层中，而神经丛层中央的神经元则将轴突向中央投射，树突径向投射到神经丛层中。至少存在两种神经元群体和光感受器间突触，这表明顶叶视网膜内的光感觉处理可能比之前设想的更为复杂。
