PHOTORECEPTOR DESIGN AND OPTICAL-PROPERTIES AFFECTING POLARIZATION SENSITIVITY IN ANTS AND CRICKETS
PHOTORECEPTOR DESIGN AND OPTICAL-PROPERTIES AFFECTING POLARIZATION SENSITIVITY IN ANTS AND CRICKETS
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DOI：
10.1007/bf00605006
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发表时间：
1987-01-01
期刊：
影响因子：
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通讯作者：
MEYER, E
中科院分区：
文献类型：
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作者：
NILSSON, DE;LABHART, T;MEYER, E
昆虫复眼背缘的小眼在解剖学和生理学上都具有特化特征，在偏振视觉中起着关键作用。在这个眼睛区域中，光感受器的偏振敏感度（PS）显著高于眼睛中的其他地方。我们比较了沙漠蚂蚁（Cataglyphis bicolor）和田野蟋蟀（Gryllus campestris）的背缘区和正常眼区的光学特性。目的是寻找在眼背缘区PS增强的原因，该情况不复杂的横纹肌扭曲。得到了三条信息：1.从定性光学实验中我们得出结论，感杆波导效应不会增强或降低PS。视网膜中去偏振的定量测量明确地表明，眼睛的所有部分通过整个视网膜深度都很好地保持偏振状态。因此，限制受体细胞固有PS的因素必须是横纹的二向色性吸收，这是由微绒毛的二向色性比和微绒毛排列的程度决定的。2.光在二向色性横纹中传播的理论模型揭示了随机微绒毛错位对PS的强烈影响。使用测量值的错位，我们预测PS背缘和非特异性视网膜之间的差异，解释以前的电生理结果。3.理论建模也证明了优势，有一个主要的微绒毛方向的横纹（如在cataglyphis背缘的情况下）。
Anatomically and physiologically specialized ommatidia at the dorsal rim of insect compound eyes play a key role in polarization vision. In this eye region the polarization sensitivity (PS) of photoreceptors is significantly higher than elsewhere in the eye. We have compared the optical properties of the dorsal rim area and normal eye region of desert ants,Cataglyphis bicolor, and field crickets,Gryllus campestris. The objective was to find the cause of the enhanced PS in the dorsal rim area of eyes where the situation is not complicated by rhabdom twist. Three pieces of information were derived:1.From qualitative optical experiments we conclude that rhabdom waveguide effects do not enhance or reduce PS. Quantitative measurements of depolarization in the retina demonstrate unambiguously that all parts of the eye retain the state of polarization very well through the full retinal depth. The factor limiting inherent PS of receptor cells must thus be the dichroic absorption of the rhabdomeres, which is determined by the dichroic ratio of microvilli and the degree of microvillar alignment.2.A theoretical model of light propagating in a dichroic rhabdom reveals a strong influence of random microvillar misalignment on PS. Using measured values of misalignment, we predict differences in PS between dorsal rim and unspecialized retina that explain previous electrophysiological results.3.Theoretical modelling also demonstrates the advantage of having a predominant microvillar direction in a rhabdom (as is the case in theCataglyphisdorsal rim).