Abstract.

Environmental temperature has a well-conserved effect on the pulse velocity and excitability of excitable biological systems. The consistency suggests that the cause originates from a fundamental principle. A physical (hydrodynamic) approach has proposed that the thermodynamic state of the hydrated interface (e.g., plasma membrane) determines the pulse behavior. This implies that the temperature effect happens because the environmental temperature affects the state of the interface in any given system. To test the hypothesis, we measured temperature-dependent phase diagrams of a lipid monolayer and studied the properties of nonlinear acoustic pulses excited along the membrane. We observed that the membrane in the fluid-gel transition regime exhibited lower compressibility (i.e., stiffer) overall with increasing temperature. Nonlinear pulses excited near the transition state propagated with greater velocity with increasing temperature, and these observations were consistent with the compressibility profiles. Excitability was suppressed significantly or ceased completely when the state departed too far from the transition regime either by cooling or by heating. The overall correlation between the pulses in the membrane and in living systems as a function of temperature supports the view that the thermodynamic state of the interface and phase transition are the key to understanding pulse propagation in excitable systems.

Graphical abstract

中文翻译：

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界面处的非线性脉冲及其与状态和温度的关系。

摘要。

环境温度对可激发生物系统的脉冲速度和可激发性具有良好的保守作用。一致性表明原因是源于基本原理。物理（流体动力学）方法已经提出，水合界面（例如质膜）的热力学状态决定了脉冲行为。这意味着发生温度效应是因为环境温度会影响任何给定系统中接口的状态。为了验证该假设，我们测量了脂质单层的温度相关相图，并研究了沿膜激发的非线性声脉冲的特性。我们观察到，膜在流体-凝胶转变过程中表现出较低的可压缩性（即，硬度越高）。在跃迁状态附近激发的非线性脉冲随着温度的升高以更大的速度传播，这些观察结果与可压缩性曲线一致。当状态通过冷却或加热偏离过渡状态太远时，兴奋性被显着抑制或完全停止。膜和生物系统中脉冲之间的整体相关性是温度的函数，这支持以下观点：界面的热力学状态和相变是理解可激发系统中脉冲传播的关键。

图形概要