Laboratory of Neurocybernetics, Research Institute for Electronic Science, Hokkaido University, Kita 12, Nishi 7, Sapporo, Hokkaido 060-0812, Japan.
Proc Biol Sci. 2012 Feb 7;279(1728):535-42. doi: 10.1098/rspb.2011.0929. Epub 2011 Jul 6.
Many insects use the polarization pattern of the sky for obtaining compass information during orientation or navigation. E-vector information is collected by a specialized area in the dorsal-most part of the compound eye, the dorsal rim area (DRA). We tested honeybees' capability of learning certain e-vector orientations by using a classical conditioning paradigm with the proboscis extension reflex. When one e-vector orientation (CS+) was associated with sugar water, while another orientation (CS-) was not rewarded, the honeybees could discriminate CS+ from CS-. Bees whose DRA was inactivated by painting did not learn CS+. When ultraviolet (UV) polarized light (350 nm) was used for CS, the bees discriminated CS+ from CS-, but no discrimination was observed in blue (442 nm) or green light (546 nm). Our data indicate that honeybees can learn and discriminate between different e-vector orientations, sensed by the UV receptors of the DRA, suggesting that bees can determine their flight direction from polarized UV skylight during foraging. Fixing the bees' heads during the experiments did not prevent learning, indicating that they use an 'instantaneous' algorithm of e-vector detection; that is, the bees do not need to actively scan the sky with their DRAs ('sequential' method) to determine e-vector orientation.
许多昆虫利用天空的极化模式在定向或导航过程中获取罗盘信息。E-vector 信息由复眼背部最深处的一个专门区域——背缘区域（DRA）收集。我们使用经典条件反射的触角延伸反射测试了蜜蜂学习特定 E-vector 方向的能力。当一种 E-vector 方向（CS+）与糖水相关联，而另一种方向（CS-）没有得到奖励时，蜜蜂可以区分 CS+和 CS-。用颜料使 DRA 失活的蜜蜂不会学习 CS+。当使用紫外线（UV）偏振光（350nm）作为 CS 时，蜜蜂可以区分 CS+和 CS-，但在蓝光（442nm）或绿光（546nm）下没有观察到区分。我们的数据表明，蜜蜂可以学习并区分由 DRA 的 UV 感受器感知到的不同 E-vector 方向，这表明蜜蜂在觅食过程中可以从偏振 UV 天空光中确定它们的飞行方向。在实验过程中固定蜜蜂的头部不会阻止学习，这表明它们使用一种“即时”的 E-vector 检测算法；也就是说，蜜蜂不需要用 DRA 主动扫描天空（“顺序”方法）来确定 E-vector 方向。
