Receptive Fields of Locust Brain Neurons Are Matched to Polarization Patterns of the Sky
Receptive Fields of Locust Brain Neurons Are Matched to Polarization Patterns of the Sky
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DOI：
10.1016/j.cub.2014.07.045
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发表时间：
2014-09-22
期刊：
影响因子：
9.2
通讯作者：
Pfeiffer, Keram
中科院分区：
文献类型：
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作者：
Bech, Miklos;Homberg, Uwe;Pfeiffer, Keram
许多动物，包括昆虫，都能够利用天体线索作为空间定向和长距离导航的参考[1]。除了直射阳光外，天空的色度梯度及其偏振模式也适合用作方向线索 [2-5]。太阳光的大气散射导致天空中出现规则的 E 矢量图案，这些矢量沿着太阳周围的同心圆排列 [5, 6]。尽管某些昆虫主要依靠天空偏振来确定空间方向 [7]，但有人认为，检测天体 E 矢量方向可能不足以区分太阳方向和反太阳方向 [8, 9]。我们在这里表明，沙漠蝗虫 Schistocerca gregaria 大脑中的偏振敏感（POL）神经元可以克服这种模糊性。中央复合体和侧副叶中 POL 单元的细胞外记录揭示了在大感受野内以同心圆排列的 E 矢量调谐，与某些太阳位置的天空偏振模式相匹配。对理想化天空偏振模式（瑞利天空）下的神经元反应进行建模表明，这些“匹配滤波器”特性使蝗虫能够仅依靠天空偏振模式进行罗盘导航，从而明确确定太阳方位角。
Many animals, including insects, are able to use celestial cues as a reference for spatial orientation and long-distance navigation [1]. In addition to direct sunlight, the chromatic gradient of the sky and its polarization pattern are suited to serve as orientation cues [2-5]. Atmospheric scattering of sunlight causes a regular pattern of E vectors in the sky, which are arranged along concentric circles around the sun [5, 6]. Although certain insects rely predominantly on sky polarization for spatial orientation [7], it has been argued that detection of celestial E vector orientation may not suffice to differentiate between solar and antisolar directions [8, 9]. We show here that polarization-sensitive (POL) neurons in the brain of the desert locust Schistocerca gregaria can overcome this ambiguity. Extracellular recordings from POL units in the central complex and lateral accessory lobes revealed E vector tunings arranged in concentric circles within large receptive fields, matching the sky polarization pattern at certain solar positions. Modeling of neuronal responses under an idealized sky polarization pattern (Rayleigh sky) suggests that these "matched filter" properties allow locusts to unambiguously determine the solar azimuth by relying solely on the sky polarization pattern for compass navigation.