Kammer A E
Fed Proc. 1976 Jul;35(9):1992-9.
In insects gas exchange may be: 1) entirely passive, when metabolic rate is low; 2) enhanced automatically by muscle contractions that produce movements, e.g., wing movements in flight; or 3) produced by ventilatory movements, particularly of the abdomen. In terrestrial insects such as locusts and cockroaches ventilatory movements are governed by a dominant oscillator in the metathoracic or anterior abdominal ganglion. The dominant oscillator overrides local oscillators in the abdominal ganglia and thus sets the rhythm for the entire abdomen, and it also controls spiracle opening and closing in several thoracic and abdominal segments. This ventilatory control mechanism appears to be different from that generating metachronal rhythms such as occur in the ventilatory and locomotory movements of aquatic arthropods. There are now several examples of rhythms, both ventilatory and locomotory, that can be generated by the central nervous system in the absence of phasic sensory feedback, but the mechanism of rhythm production is not known. Studies of ganglionic output suggest that neuronal oscillators can produce a range of frequencies and that some oscillators may be employed in more than one function or behavior. The mechanisms by which central oscillators are coupled to the output motorneurons are also not known; large phase changes suggest that in some cases different coupling interneurons are active. Intracellular recordings from identified neurons have begun to clarify the important roles of interneurons in the production of motor patterns.
在昆虫中，气体交换可能有以下几种情况：1）当代谢率较低时，完全是被动的；2）通过产生运动的肌肉收缩自动增强，例如飞行中的翅膀运动；或者3）由通气运动产生，特别是腹部的通气运动。在蝗虫和蟑螂等陆生昆虫中，通气运动由后胸或腹部前神经节中的主导振荡器控制。主导振荡器凌驾于腹部神经节中的局部振荡器之上，从而为整个腹部设定节律，并且它还控制几个胸段和腹段气门的开闭。这种通气控制机制似乎与产生如在水生节肢动物的通气和运动运动中出现的顺序性节律的机制不同。现在有几个通气和运动节律的例子，它们可以在没有阶段性感觉反馈的情况下由中枢神经系统产生，但节律产生的机制尚不清楚。对神经节输出的研究表明，神经元振荡器可以产生一系列频率，并且一些振荡器可能用于多种功能或行为。中枢振荡器与输出运动神经元耦合的机制也不清楚；大的相位变化表明在某些情况下不同的耦合中间神经元是活跃的。对已识别神经元的细胞内记录已开始阐明中间神经元在运动模式产生中的重要作用。
