Analysis of color vision mechanism in a microbrain

1)Papilio视觉系统中波长信息的处理机制首先，我们分析了Papilio视网膜特征宽带受体的光谱来源。宽带受体被证明同时表达吸收绿色和吸收橙色的视觉色素，两者同时起作用。其次，我们在EM水平对第一个视神经节--椎板进行了详细的解剖。在那里，我们发现除了光感受器和二级视觉中间神经元之间的突触联系外，还有许多光感受器之间的联系。连续的EM切片观察显示，三种类型的光谱异质性小眼的光感受器间连接模式不同。第三，我们使用针对神经递质候选者的特定抗体，如5-羟色胺、酪胺、组胺和γ-氨基丁酸等，对乳头脑进行了免疫细胞化学分析。2)对乳头颜色视觉功能的行为分析我们建立了一个前…更周到的方法是让Papilio辨别单色光。使用该协议，我们测量了觅食飞行的动作谱以及喙的伸展。似乎Papilio实际上可以看到300-700 nm的波长范围内的光。我们还建立了Y迷宫实验方案，使Papilio能够区分来自一定距离的两个刺激。因此，我们测量了觅食凤蝶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。其大小与它们的特殊分辨率极限相当。我们还进行了一些初步的实验，以检验它们的波长分辨能力和混色现象等。3)乳突以外昆虫的复眼结构我们以小白蝶菜粉蝶和蜜蜂意大利蜜蜂为材料，对昆虫复眼进行了比较解剖学和生理学研究。通过对编码视觉色素视蛋白的mRNAs在视网膜中的定位，我们发现这两个物种的眼睛都由三种类型的光谱不同的小眼组成，就像Papilio一样。我们进一步分析了Pieris的光感受器光谱敏感性。Pieris的眼睛有三种长波感受器，绿色、红色和深红色的感受器，都共享一种视觉色素PRL。光谱灵敏度的差异可归因于周边颜料的过滤效应，这些色素吸收了传播细长条纹的光的边界波。较少

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