Motion and color information processing in the Papilio visual system

在过去的一年里，我们收集了大量关于Parantica Sita光感受器的光谱和偏振特性的数据集。今年我们将这些受体分为五个不同的光谱组，包括紫外线(UV)、蓝(B)、宽绿(BG)、窄绿(Ng)和双峰绿(DG)光感受器。在每个小眼内，从R1到R8有8个主要的感光细胞位置。由于染料注入实验，我们能够证明UV和B光受体只出现在R1和R2位置，而其他受体出现在R3-R8位置。我们还用电子显微镜对小眼结构进行了仔细的检查，发现眼睛背缘的小眼比眼睛其他区域的小眼更长方形。眼睛后缘小眼微绒毛的方向似乎专门用于增强偏振敏感度，尽管在眼睛的这一区域没有记录到电信号。在行为方面，蝴蝶被证明在被拴住时不愿飞行。我们发现，在蝴蝶被拴住的情况下，光流的使用可能有助于增加它的飞行动力。与系留飞行相比，蝴蝶在网笼中自由飞行时，表现出足够的飞行动力来延长实验飞行时间。

In the previous year, we collected an extensive dataset on the spectral and polarisation properties of the photoreceptors of Parantica sita. This year we classified these receptors into five distinct spectral groups including ultraviolet (UV), blue (B), broad green (bG), narrow green (nG) and double peaking green (dG) photoreceptors. Within each ommatidium there are 8 main photoreceptor positions from R1 to R8. Due to the dye-injection experiments, we were able demonstrate that UV and B photoreceptors only occur at the R1 and R2 positions while other receptors occur in the R3-R8 positions. We also performed a close examination of ommatidial structure using electron microscopy and revealed that ommatidia at the dorsal rim of the eye were more rectangular than ommatidia in other regions of the eye. The microvilli orientation in the ommatidia of the dorsal rim area of the eye seem specialised for enhanced polarisation sensitivity although no electrical recordings have been made in this region of the eye.On the behavioural side, butterflies have proven reluctant to fly while being tethered. We have discovered that the use of optic flow may be useful to increase flight motivation of the butterfly while it is tethered. In contrast to tethered flight, butterflies display enough flight motivation for prolonged experimental runs during free-flight in a netted cage.