Variability of blowfly head optomotor responses
Variability of blowfly head optomotor responses
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苍蝇头部光运动反应的变异性
DOI：
10.1242/jeb.027060
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发表时间：
2009
影响因子：
2.8
通讯作者：
A. Warzecha
中科院分区：
文献类型：
--
作者：
Ronny Rosner;M. Egelhaaf;Jan Grewe;A. Warzecha
动物的行为反应是可变的，即使当动物多次经历相同的感觉输入时。这种可变性可能来自神经系统固有的随机过程。此外，动物的内部状态可能会影响特定的行为反应。在本研究中，我们分析了视觉诱导的头部俯仰反应的系留绿头苍蝇高速摄影的变化。我们发现这些optomotor反应是高度可变的振幅。大部分的可变性可以归因于两个不同的内部状态的苍蝇与高和低optomotor增益，分别。即使在给定的活动状态下，头部视动反应也存在一些可变性。这种变化的量对于两个视动器增益状态是不同的。此外，这两种活动状态可以区分在一个很好的时间尺度上，没有视觉刺激，在发生的基础上特有的头部抖动运动。磁头抖动沿着高增益光学马达响应和Haltere振荡。Halteres是进化改造后的后翅，当绿头苍蝇行走或飞行时摆动。它们的主要功能是通过检测科里奥利力作为平衡器官，并调节凝视稳定。然而，它们的基本振荡活性也被认为提供了增益调节信号。我们的实验表明，halteres是没有必要的高增益头间距发生。然而，我们发现halteres负责的一个组成部分的头部抖动运动。这一成分可能是它们作为平衡和稳定视线器官的功能的必然结果。
SUMMARY Behavioural responses of an animal are variable even when the animal experiences the same sensory input several times. This variability can arise from stochastic processes inherent to the nervous system. Also, the internal state of an animal may influence a particular behavioural response. In the present study, we analyse the variability of visually induced head pitch responses of tethered blowflies by high-speed cinematography. We found these optomotor responses to be highly variable in amplitude. Most of the variability can be attributed to two different internal states of the flies with high and low optomotor gain, respectively. Even within a given activity state, there is some variability of head optomotor responses. The amount of this variability differs for the two optomotor gain states. Moreover, these two activity states can be distinguished on a fine timescale and without visual stimulation, on the basis of the occurrence of peculiar head jitter movements. Head jitter goes along with high gain optomotor responses and haltere oscillations. Halteres are evolutionary transformed hindwings that oscillate when blowflies walk or fly. Their main function is to serve as equilibrium organs by detecting Coriolis forces and to mediate gaze stabilisation. However, their basic oscillating activity was also suggested to provide a gain-modulating signal. Our experiments demonstrate that halteres are not necessary for high gain head pitch to occur. Nevertheless, we find the halteres to be responsible for one component of head jitter movements. This component may be the inevitable consequence of their function as equilibrium and gaze-stabilising organs.