SCOTOPIC AND PHOTOPIC VISION IN CALIFORNIA GROUND SQUIRREL - PHYSIOLOGICAL AND ANATOMICAL EVIDENCE
SCOTOPIC AND PHOTOPIC VISION IN CALIFORNIA GROUND SQUIRREL - PHYSIOLOGICAL AND ANATOMICAL EVIDENCE
复制标题
DOI：
10.1002/cne.901650207
复制
发表时间：
1976-01-01
影响因子：
2.5
通讯作者：
SILVERMAN, MS
中科院分区：
文献类型：
--
作者：
JACOBS, GH;FISHER, SK;SILVERMAN, MS
加州地松鼠是一种高度昼夜活动的物种，以前被认为有全视锥视网膜。这个问题在生理学和解剖学实验中得到了重新检验。用视网膜电信号(ERG)测量不同适应条件下眼睛的光谱敏感度。浦肯野转移的发生是可以证明的，尽管有一些迹象表明，并不是该物种的所有成员都表现出这种转移。这种松鼠适应黑暗的眼睛的光谱敏感度接近于典型哺乳动物视紫红质的预测。光适应使光谱敏感度向约525 nm的峰值位置移动。结果表明，具有不同光谱灵敏度的两种机制对光记录ERG有贡献。这两种机制对ERG的贡献程度被发现与两者对视觉行为的贡献程度显著不同。我们的解剖学结果表明，加州黄鼠的视网膜有两个结构不同的光感受器，根据不同的标准，可以将其分为锥状和杆状。杆状受体约占总数的6-7%。这两种光感受器类型在其内节的位置、外节的大小、外节的超微结构以及末端结构和组织上都有所不同。
The California ground squirrel is a highly diurnal species previously thought to have an all‐cone retina. This issue was re‐examined in physiological and anatomical experiments. The electroretinogram (ERG) was used to measure the spectral sensitivity of the eye under different conditions of adaptation. The occurrence of a Purkinje shift could be demonstrated, although there was some indication that not all members of this species show such a shift. Spectral sensitivity of the dark‐adapted eye of this squirrel is close to that predicted by a typical mammalian rhodopsin. Light adaptation produces a shift in spectral sensitivity to a peak location of about 525 nm. It was shown that two mechanisms having different spectral sensitivities contribute to the photopically recorded ERG. The degree to which these two mechanisms contribute to the ERG was found to be strikingly different from the degree to which the two contribute to visual behavior.Our anatomical results indicate that the retina of the California ground squirrel has two structurally distinct photoreceptors which, on the basis of various criteria, can be classified as cone and rod‐like. The rod‐like receptors comprise about 6–7% of the total. The two photoreceptor types differ in placement of their inner segments, size of their outer segments, outer segment ultrastructure, and terminal structure and organization.