Simulations of neuromuscular control in lamprey swimming
Simulations of neuromuscular control in lamprey swimming
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DOI：
10.1098/rstb.1999.0441
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发表时间：
1999-05-29
期刊：
影响因子：
--
通讯作者：
Grillner, S
中科院分区：
文献类型：
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作者：
Ekeberg, Ö;Grillner, S
脊椎动物运动的神经元生成已在七鳃鳗中进行了广泛的研究。不同抽象级别的模型被用来描述该系统，从抽象的非线性振荡器到包含多个隔室和最相关离子通道的 Hodgkin-Huxley 表示的互连模型神经元。为了通过模拟研究感官反馈的作用，最终还需要将机械运动纳入模型中。通过使用肌肉激活、身体力学、抵消水力以及通过牵张感受器和前庭器官的感觉反馈的简化模型，我们已经能够闭合反馈回路，从而能够研究神经元和机械系统之间的相互作用。神经力学模拟表明，当前已知的网络足以生成一整套游泳模式。以不同的速度和不同的波长游泳，以及侧转的表现都可以通过简单地改变脑干输入来实现。俯仰和横滚动作背后的神经机制尚不清楚。我们提出了“交叉振荡器”假说，其中假定背侧和腹侧回路部分分离。该系统的神经力学模拟表明，它还能够产生逼真的俯仰转动和滚动，并且前庭信号可以稳定游泳期间的姿势。
The neuronal generation of vertebrate locomotion has been extensively studied in the lamprey. Models at different levels of abstraction are being used to describe this system, from abstract nonlinear oscillators to interconnected model neurons comprising multiple compartments and a Hodgkin-Huxley representation of the most relevant ion channels. To study the role of sensory feedback by simulation, it eventually also becomes necessary to incorporate the mechanical movements in the models. By using simplifying models of muscle activation, body mechanics, counteracting water forces, and sensory feedback through stretch receptors and vestibular organs, we have been able to close the feedback loop to enable studies of the interaction between the neuronal and the mechanical systems. The neuromechanical simulations reveal that the currently known network is sufficient for generating a whole repertoire of swimming patterns. Swimming at different speeds and with different wavelengths, together with the performance of lateral turns can all be achieved by simply varying the brainstem input. The neuronal mechanisms behind pitch and roll manoeuvres are less clear. We have put forward a 'crossed-oscillators' hypothesis where partly separate dorsal and ventral circuits are postulated. Neuromechanical simulations of this system show that it is also capable of generating realistic pitch turns and rolls, and that vestibular signals can stabilize the posture during swimming.