Laboratory of Neuroethology, SOKENDAI, The Graduate University for Advanced Studies, Hayama, Kanagawa, Japan.
Laboratory of Neuroethology, SOKENDAI, The Graduate University for Advanced Studies, Hayama, Kanagawa, Japan.
Curr Biol. 2022 Feb 7;32(3):R114-R115. doi: 10.1016/j.cub.2021.12.032.
Colour is an important visual modality for many animals including insects. The flower-foraging swallowtail butterfly Papilio xuthus has spectrally acute chromatic vision using UV-, blue-, green- and red-sensitive photoreceptors. The spectral organization of Papilio's retina is well understood but, as for other insects, how chromatic information is processed in higher order brain regions remains unclear. To identify neurons underlying color perception in Papilio, we have investigated the spectral properties of the visual inputs to the mushroom body (MB), a brain region implicated in learning and memory. By recording intracellular responses to a series of monochromatic lights, combined with dye injection, we have revealed a wide variety of spectral responses in three morphologically distinct neuron types. These heterogeneous responses are characterized by colour opponency and sharp tuning to particular wavelengths, which do not in general align with the sensitivities of the retinal photoreceptors, and presumably contribute to Papilio's acute wavelength discrimination. This finding provides new insights into the processing underlying insect colour vision.
颜色是许多动物（包括昆虫）的一种重要视觉模式。花觅食燕尾蝶 Papilio xuthus 利用紫外线、蓝色、绿色和红色敏感光感受器具有光谱敏锐的色觉。Papilio 视网膜的光谱组织已经得到很好的理解，但与其他昆虫一样，色觉信息在更高阶的大脑区域中是如何处理的仍然不清楚。为了鉴定 Papilio 中颜色感知背后的神经元，我们研究了蘑菇体（MB）的视觉输入的光谱特性，MB 是一个与学习和记忆有关的大脑区域。通过记录对一系列单色光的细胞内反应，结合染料注射，我们揭示了三种形态上不同的神经元类型中广泛的光谱反应。这些异构反应的特征是颜色对立和对特定波长的尖锐调谐，通常与视网膜光感受器的灵敏度不一致，并且可能有助于 Papilio 对波长的敏锐区分。这一发现为昆虫色觉的处理提供了新的见解。
