Examining whether and how the rhythms of limb and breathing movements interact is highly informative about the mechanistic origin of hyperpnoea to exercise. However, studies have failed to reveal regularities. In particular, whether breathing frequency is inherently proportional to limb velocity and/or imposed by a synchronization of breaths to strides is still unclear. Here, we examined the specifications of respiratory changes during running in mice, the premier model for investigating, in a standardized manner, complex integrative tasks including adaptive breathing. We show that respiratory rate increases during running to a fixed and stable value, irrespective of trotting velocities and of inclination. Yet, respiratory rate was further enhanced during gallop. We also demonstrate the absence of temporal coordination of breaths to strides at any speed, intensity or gait. Our work thus highlights a hardwired mechanism that sets respiratory frequency independently of limb movements but in relation with the engaged locomotor program.

中文翻译：

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奔跑的小鼠的独立呼吸和运动节律

检查肢体节律和呼吸运动是否相互作用以及如何相互作用，这对运动性呼吸亢进的机制起源非常有用。但是，研究未能揭示规律性。尤其是，呼吸频率是否固有地与肢体速度成正比和/或由呼吸同步到步幅所强加仍然不清楚。在这里，我们检查了小鼠跑步过程中呼吸变化的规格，这是用于以标准化方式调查包括自适应呼吸在内的复杂综合任务的主要模型。我们显示，无论跑步速度和倾斜度如何，跑步期间呼吸频率都会增加到固定且稳定的值。然而，驰gall期间呼吸频率进一步提高。我们还证明了在任何速度，强度或步态下，呼吸的时间协调性都没有大步迈进。因此，我们的工作着重强调了一种硬连线机制，该机制可独立于肢体运动来设置呼吸频率，但与参与的运动程序有关。