Poulet James F A, Hedwig Berthold
Laboratory of Sensory Processing, Brain Mind Institute, Faculty of Life Science, SV-BMI-LSENS AAB105, Station 15, Ecole Polytechnique Fédérale de Lausanne, CH-1015 Lausanne, Switzerland.
Proc Natl Acad Sci U S A. 2005 Oct 25;102(43):15665-9. doi: 10.1073/pnas.0505282102. Epub 2005 Oct 14.
Many groups of insects are specialists in exploiting sensory cues to locate food resources or conspecifics. To achieve orientation, bees and ants analyze the polarization pattern of the sky, male moths orient along the females' odor plume, and cicadas, grasshoppers, and crickets use acoustic signals to locate singing conspecifics. In comparison with olfactory and visual orientation, where learning is involved, auditory processing underlying orientation in insects appears to be more hardwired and genetically determined. In each of these examples, however, orientation requires a recognition process identifying the crucial sensory pattern to interact with a localization process directing the animal's locomotor activity. Here, we characterize this interaction. Using a sensitive trackball system, we show that, during cricket auditory behavior, the recognition process that is tuned toward the species-specific song pattern controls the amplitude of auditory evoked steering responses. Females perform small reactive steering movements toward any sound patterns. Hearing the male's calling song increases the gain of auditory steering within 2-5 s, and the animals even steer toward nonattractive sound patterns inserted into the species-specific pattern. This gain control mechanism in the auditory-to-motor pathway allows crickets to pursue species-specific sound patterns temporarily corrupted by environmental factors and may reflect the organization of recognition and localization networks in insects.
许多昆虫群体都是利用感官线索来定位食物资源或同种个体的专家。为了实现定向，蜜蜂和蚂蚁会分析天空的偏振模式，雄性飞蛾会沿着雌性的气味羽流定向，而蝉、蚱蜢和蟋蟀则利用声学信号来定位鸣叫的同种个体。与涉及学习的嗅觉和视觉定向相比，昆虫定向背后的听觉处理似乎更多地是由基因决定且固定连接的。然而，在这些例子中的每一个中，定向都需要一个识别过程来识别关键的感官模式，并与引导动物运动活动的定位过程相互作用。在这里，我们描述了这种相互作用。使用一个灵敏的轨迹球系统，我们表明，在蟋蟀的听觉行为中，针对物种特异性歌声模式进行调整的识别过程控制着听觉诱发转向反应的幅度。雌性对任何声音模式都会做出小的反应性转向运动。听到雄性的求偶歌声会在2至5秒内增加听觉转向的增益，而且这些动物甚至会转向插入到物种特异性模式中的无吸引力声音模式。听觉到运动途径中的这种增益控制机制使蟋蟀能够追踪暂时被环境因素破坏的物种特异性声音模式，并且可能反映了昆虫中识别和定位网络的组织方式。
