Interaction of compass sensing and object-motion detection in the locust central complex
Interaction of compass sensing and object-motion detection in the locust central complex
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DOI：
10.1152/jn.00927.2016
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发表时间：
2017-07-01
影响因子：
2.5
通讯作者：
Homberg, Uwe
中科院分区：
文献类型：
--
作者：
Bockhorst, Tobias;Homberg, Uwe
目标导向的行为通常会因不可预测的事件而变得复杂，例如在定向移动过程中出现捕食者。这种情况需要适应性反应，如躲避动作，随后进行重新定向和航向修正。在这里，我们研究了这种情况在一种昆虫--沙漠蝗虫中可能的神经基础。与其他昆虫一样，它的空间定向感强烈依赖于中央复合体，即一组中线脑神经毛发。中央建筑群容纳了天空罗盘单元，这些单元发出天光偏振面的信号，从而指示动物相对于太阳的转向方向。这些细胞中的大多数还会对驱动快速感觉-运动神经回路逃逸的微小移动物体做出反应。在这里，我们研究了运动物体的呈现如何影响COMPASS信号传递过程中神经元的活动。细胞有两种反应方式之一：在一些神经元中，对运动物体的反应简单地添加到罗盘反应中，而罗盘反应是在静止偏振光持续刺激期间适应的。相比之下，当出现运动物体时，其他神经元不适应，即重新获得对偏振光的完整指南针反应。我们认为，后一种情况可能有助于为动物逃跑后的重新定向做准备。基于中枢复合体结构的神经元网络可以通过系统CL柱状输入神经元对偏振光适应的动力学和幅度的轻微变化来解释这两种反应。几种昆虫中枢复合体中值得注意的神经元通过对天空偏振模式的敏感来指示方向。在蝗虫中，这些神经元也会对移动的物体做出反应。我们在这里表明，在偏振光呈现期间，对运动物体的反应推翻了它们的COMPASS信号，或者恢复了适应的抑制性和兴奋性COMPASS反应。提出了一个网络模型来解释这些响应的变化，这些响应可能用于在躲避动作后改变飞行或行走的方向。
Goal-directed behavior is often complicated by unpredictable events, such as the appearance of a predator during directed locomotion. This situation requires adaptive responses like evasive maneuvers followed by subsequent reorientation and course correction. Here we study the possible neural underpinnings of such a situation in an insect, the desert locust. As in other insects, its sense of spatial orientation strongly relies on the central complex, a group of midline brain neuropils. The central complex houses sky compass cells that signal the polarization plane of skylight and thus indicate the animal's steering direction relative to the sun. Most of these cells additionally respond to small moving objects that drive fast sensory-motor circuits for escape. Here we investigate how the presentation of a moving object influences activity of the neurons during compass signaling. Cells responded in one of two ways: in some neurons, responses to the moving object were simply added to the compass response that had adapted during continuous stimulation by stationary polarized light. By contrast, other neurons disadapted, i.e., regained their full compass response to polarized light, when a moving object was presented. We propose that the latter case could help to prepare for reorientation of the animal after escape. A neuronal network based on central-complex architecture can explain both responses by slight changes in the dynamics and amplitudes of adaptation to polarized light in CL columnar input neurons of the system.NEW & NOTEWORTHY Neurons of the central complex in several insects signal compass directions through sensitivity to the sky polarization pattern. In locusts, these neurons also respond to moving objects. We show here that during polarized-light presentation, responses to moving objects override their compass signaling or restore adapted inhibitory as well as excitatory compass responses. A network model is presented to explain the variations of these responses that likely serve to redirect flight or walking following evasive maneuvers.