Flight initiation and maintenance deficits in flies with genetically altered biogenic amine levels
Flight initiation and maintenance deficits in flies with genetically altered biogenic amine levels
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DOI：
10.1523/jneurosci.2704-07.2007
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发表时间：
2007-10-10
影响因子：
5.3
通讯作者：
Duch, Carsten
中科院分区：
文献类型：
--
作者：
Brembs, Bjoern;Christiansen, Frauke;Duch, Carsten
昆虫飞行是速度最快、强度最大且能量需求最高的运动行为之一。它在多个层面受到生物胺章鱼胺的调节。在中枢神经系统内，章鱼胺直接作用于飞行中枢模式发生器，并影响动机状态。在周边，章鱼胺使感觉受体敏感化，改变肌肉收缩动力学，并增强飞行肌糖酵解。本研究通过对果蝇进行遗传和药理学操作，探讨章鱼胺及其前体酪胺在飞行行为中的作用。章鱼胺不是启动飞行的天然信号，因为缺乏章鱼胺的果蝇[酪胺 - β - 羟化酶（TβH）缺失突变体]能够飞行。然而，与野生型对照相比，它们在飞行启动和飞行维持方面表现出显著差异。TβH突变体的飞行器官的形态、运动学和发育未受损害，因为TβH突变体的翅拍频率和振幅、飞行肌结构以及飞行运动神经元的整体树突结构均未受影响。因此，成年果蝇的飞行行为表型可以被急性挽救。通过补充章鱼胺以及阻断在TβH突变体中富集的酪胺的受体，可以挽救飞行缺陷。相反，去除所有含有章鱼胺或酪胺的神经元会产生与TβH突变体相同的表型。因此，章鱼胺和酪胺系统同时参与调节飞行启动和维持。不同组的挽救实验表明这两种胺的作用位点不同。这些发现与一个由多种胺构成的复杂系统相符合，该系统在多个层面协调对运动行为的控制，而不是单一胺引发单一行为。
Insect flight is one of the fastest, most intense and most energy-demanding motor behaviors. It is modulated on multiple levels by the biogenic amine octopamine. Within the CNS, octopamine acts directly on the flight central pattern generator, and it affects motivational states. In the periphery, octopamine sensitizes sensory receptors, alters muscle contraction kinetics, and enhances flight muscle glycolysis. This study addresses the roles for octopamine and its precursor tyramine in flight behavior by genetic and pharmacological manipulation in Drosophila. Octopamine is not the natural signal for flight initiation because flies lacking octopamine [tyramine-beta-hydroxylase (T beta H) null mutants] can fly. However, they show profound differences with respect to flight initiation and flight maintenance compared with wild-type controls. The morphology, kinematics, and development of the flight machinery are not impaired in T beta H mutants because wing-beat frequencies and amplitudes, flight muscle structure, and overall dendritic structure of flight motoneurons are unaffected in T beta H mutants. Accordingly, the flight behavior phenotypes can be rescued acutely in adult flies. Flight deficits are rescued by substituting octopamine but also by blocking the receptors for tyramine, which is enriched in T beta H mutants. Conversely, ablating all neurons containing octopamine or tyramine phenocopies T beta H mutants. Therefore, both octopamine and tyramine systems are simultaneously involved in regulating flight initiation and maintenance. Different sets of rescue experiments indicate different sites of action for both amines. These findings are consistent with a complex system of multiple amines orchestrating the control of motor behaviors on multiple levels rather than single amines eliciting single behaviors.