THE OCELLAR COMPONENT OF FLIGHT EQUILIBRIUM CONTROL IN DRAGONFLIES
THE OCELLAR COMPONENT OF FLIGHT EQUILIBRIUM CONTROL IN DRAGONFLIES
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DOI：
10.1007/bf00609936
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发表时间：
1981-01-01
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影响因子：
--
通讯作者：
STANGE, G
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文献类型：
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作者：
STANGE, G
在蜻蜓H. tau的光诱发头部反射的动力学，在光条件下选择，以最佳地解决ocelli，描述。这种反应只在飞行过程中发生。定位于正中细胞的光刺激会引起头部围绕俯仰轴的运动。阈值大约是107个光子。cm-2 .cntdot。s - 1。随着强度的增加，响应逐渐变快，但振幅不增加。通过定位于侧半轴的灯光刺激，可以唤起头部围绕滚动轴的运动，其阈值和动态与俯仰响应相似。当动物两侧的两个源交替切换时，反应最强烈。没有证据表明外侧输入和正中输入之间存在相互作用。在中间光源的持续照明期间，头部无限期地向它倾斜，并且增加强度只会导致头部位置的微小额外变化。降低强度导致磁头远离源的大运动，然后系统迅速重新适应，磁头返回到原位（高通滤波）。如果增量脉冲叠加在稳定的背景上，则其影响的大小是其持续时间和幅度的函数。如果中位源由频率高于高通截止频率的方波调制，则响应的幅度与调制深度成正比，与超过4个对数单位的平均强度无关。当强度< 1011光子cm-2 s-1时，光谱灵敏度在绿色处达到最大值，超过紫外线灵敏度的5倍；在较高的强度下，反应变得对紫外线比绿色更敏感（反向浦肯杰位移）。逆浦肯野位移可能是一种功能适应，以优化在昏暗光线和阳光直射下天空和地面对比的可探测性。行为反应的动力学可以在很大程度上由已知的细胞系统神经元元素的特性来解释。
The dynamics of light-evoked head reflexes in the dragonfly H. tau, under light conditions selected to optimally address the ocelli, are described. The responses occur only during flight. Stimulation by a light positioned to address the median ocellus evokes a head movement around the pitch axis. The threshold is on the order of 107 photons .cntdot. cm-2 .cntdot. s-1. With increasing intensity, the responses become progressively faster but do not increase in amplitude. Stimulation by lights positioned to address the lateral ocelli evokes head movements around the roll axis with a similar threshold and similar dynamics as in the pitch responses. The responses are strongest when 2 sources at either side of the animal are switched in alternation. No evidence is found for interactions between the lateral and the median inputs. During sustained illumination from the median source, the head is tilted towards it indefinitely, and increasing the intensity causes only a small additional change of head position. Decreasing the intensity causes a large movement of the head away from the source, and then the system readapts rapidly and the head returns to the on-position (high pass filtering). If increment pulses are superimposed on a steady background, the magnitude of their effect is a function of both their duration and amplitude. If the median source is modulated by a square wave of a frequency above the high pass cut-off, the amplitudes of the responses are proportional to modulation depths and independent of average intensity over 4 log units. At intensities < 1011 photons cm-2 s-1, the spectral sensitivity has a maximum in the green, exceeding the UV-sensitivity by a factor of 5; at higher intensities the responses become more sensitive to UV than to green (reverse Purkinjie shift). The reverse Purkinje shift is probably a functional adaptation to optimize the detectability of the contrast between sky and ground both in dim light and in direct sunlight. The dynamics of the behavioral responses can be largely accounted for by known properties of the neuronal elements of ocellar systems.