Analysis of color vision mechanism in a microbrain

1)凤蝶视觉系统中波长信息处理的机制首先，我们分析了凤蝶视网膜中特征性宽带受体的光谱来源。宽带受体共表达吸收绿色和吸收橙色的视色素，两者同时起作用。其次，在电镜水平上对第一视神经节（椎板）进行了详细的解剖。在那里，我们发现了许多感光细胞间的连接，除了光感受器和二级视觉中间神经元之间的突触连接。连续电镜观察显示，三种光谱异质性小眼的感光细胞间连接模式不同。第三，我们用5-羟色胺、酪胺、组胺和GABA等神经递质的特异性抗体对凤蝶脑进行了免疫细胞化学分析。2）凤蝶色觉功能的行为学分析 关于我们 实验方法是让凤蝶分辨单色光。通过使用该协议，我们测量了觅食飞行以及长鼻子延伸的动作谱。看来凤蝶实际上可以看到300- 700 nm波长范围的光。我们还建立了一个Y-迷宫实验方案，使凤蝶区分一定距离的两个刺激。因此，我们测量了觅食凤蝶的颜色检测的最小视角：它们可以区分直径约为1度的目标的颜色。尺寸与其特殊分辨率限制相当。我们还进行了一些初步的实验，以检查它们的波长辨别能力和“颜色混合”现象等。3）非蝶类昆虫的复眼结构我们用小白色蝴蝶Pieris raiscrucivora和蜜蜂Apis mellifera进行了昆虫复眼的比较解剖学和生理学研究。通过在视网膜中定位编码视觉色素视蛋白的mRNA，我们发现这两个物种的眼睛包括三种类型的光谱上不同的小眼在凤蝶。进一步分析了粉蝶属植物光感受器的光谱敏感性。粉蝶的眼睛有三类长波长受体，即绿色、红色和深红色受体，它们都共享一种视觉色素PrL。光谱灵敏度的差异可归因于感杆周围色素的过滤作用，这些色素吸收在细长感杆上传播的光的边界波。少

1)Mechanism of wavelength information processing in the Papilio visual systemFirstly, we analyzed the spectral origin of characteristic broadband receptors in the Papilio retina. The broadband receptors were shown to coexpress green-absorbing and orange-absorbing visual pigment both functioning at the same time. Secondly, we carried out detailed anatomy of the first optic ganglion, the lamina, at the EM level. There we found numerous interphotoreceptor connections in addition to the synaptic connections between photoreceptors and second order visual interneurons. Observation of serial EM sections revealed that the pattern of interphotoreceptor connection is different among three types of spectrally heterogeneous ommatidia. Thirdly we initiated an immunocytochemical analysis of the Papilio brain using specific antibodies against neurotransmitter candidates, such as serotonin, tyramine, histamine, and GABA, etc.2)Behavioral analysis of color vision function in PapilioWe established an ex … More perimental method to let Papilio to discriminate monochromatic lights. By using the protocol we measured the action spectrum of foraging flight as well as proboscis extension. It appeared that Papilio could actually see the light of the wavelength range of 300-700nm. We also established a Y-maze experiment protocol to make Papilio to discriminate two stimuli from certain distance. We thus measured the minimum visual angle for color detection of foraging Papilio : they could discriminate color of the target whose diameter is about 1 degree. The size is comparable to their special resolution limit. We also carried out some preliminary experiments to check their wavelength discrimination ability and the 'color-mixture' phenomenon, etc.3)Compound eye structure in insects other than PapilioWe carried out a comparative anatomy and physiology of insect compound eyes, using the small white butterfly, Pieris rapae crucivora, and the honeybee, Apis mellifera. By localizing mRNAs encoding visual pigment opsins in the retina, we found the eyes of both species consist of three types of spectrally distinct ommatidia as in Papilio. We further analyzed photoreceptor spectral sensitivities in Pieris. The Pieris eyes have three classes of long wavelength receptors, green, red, and deep-red receptors, all share a visual pigment PrL. The difference hi the spectral sensitivities is attributable to the filtering effect of perirhabdomeral pigments that absorb boundary wave of light propagating the slender rhabdom. Less