BIOELECTROMAGNETIC MECHANISMS AND THRESHOLDS

目标：生物电磁效应的可信度需要 令人信服的实验和对相互作用的理论理解 机制和阈值。在这里，我们提出了基本的理论模型 相互作用机制、生物背景和噪声。我们将强调 可合理建模的蜂窝子系统，并将寻求：(1) 确定关键参数(例如，细胞聚集大小、酶 动力学，膜电介电常数，epsilon(M))，(2)依赖于 对参数的相互作用(例如，跨膜通量与 E2(E))、(3)参数的噪声或波动水平(例如，1/f 跨膜电压中的噪声)，(4)幅度、频谱 以及生物背景场的波动(例如，在 远端组织部位)，以及(5)相互作用的阈值条件 发生(例如，使用组合的信噪比与 特定的交互机制)。意义：有可能 “微弱的”电磁场生物效应产生了相当大的影响 因为明显违反基本物理定律而引起的争议。两者都有 组织中的生物产生的场(“生物背景”)和 基本的物理波动(“噪音”)被认为排除了 “微弱的”生物效应。因此，与“探测”有关的基本问题 生物系统对电磁场的影响必须直接 对峙。在此上下文中，“检测”用于指示 响应实际上是由于外部电磁场(例如，50和 60赫兹环境场)，并且不会被以下组合所淹没 背景和噪音。此外，为了改变细胞功能， 物理检测过程必须导致生物化学的改变。除非是这样 检测可以在背景、噪声和 机制，所谓的影响，或它们的缺乏，都是不可信的。之前 7前期工作：我们为(1)建立了理论模型 电池对电场响应的热噪声限值，(2) 膜酶的电构象偶联，(3)电穿孔- 相关现象，并得到了(4)蚀变模型的初步结果 分子突起，以及(5)磁相互作用的阈值 细胞内可溶分子。方法：我们将治疗细胞 可以用物理模型可信地表示的子系统，以及 这为一个或多个生化途径提供了可能的耦合。 与外部电磁场相互作用的建模将是 已开发，重点是预测对关键参数的依赖。 我们的主要假设涉及膜的电构象变化。 实体(膜大分子、膜本身和 膜/高分子复合体)。我们的第二个假设涉及 可溶的细胞内分子(例如DNA)，以及可能的细胞内分子 通过感应电场的磁相互作用。生物学 背景场和本征噪声将与理论相结合 估计生物电磁效应阈值的模型。

AIMS: The credibility of bioelectromagnetic effects requires both convincing experiments and theoretical understanding of interaction mechanisms and thresholds. Here we propose theoretical modelling of basic interaction mechanisms, biological background and noise. We will emphasize cellular subsystems that can be reasonably modelled, and will seek: (1) identification of the key parameters, (e.g., cell aggregate size, enzyme kinetics, membrane electrical permittivity, epsilon(m)), (2) dependence of an interaction on the parameters (e.g., transmembrane flux proportional to E2(e)), (3) noise or fluctuation levels for the parameters, (e.g., 1/f noise in the transmembrane voltage), (4) the magnitude, frequency spectrum and fluctuations in biological background fields (e.g., an EGC field at a distant tissue site), and (5) threshold conditions for an interaction to occur (e.g., use of a combined signal-to-(background + noise) ratio with a particular interaction mechanism). SIGNIFICANCE: The possibility of "weak" electromagnetic field biological effects has generated considerable controversy because of apparent violations of basic physical laws. Both biologically generated fields in tissue ("biological background") and fundamental physical fluctuations ("noise") have been cited as precluding "weak" biological effects. Thus, basic questions relating to "detection" of electromagnetic fields by biological systems must be directly confronted. In this context, "detection" is used to indicate that a response is really due to an external electromagnetic field (e.g., 50 and 60 Hz environmental fields), and is not overwhelmed by a combination of background and noise. Further, in order to alter cell function, the physical detection process must lead to altered biochemistry. Unless such detection can be understood in the context of background, noise and mechanism, alleged effects, or their absence, will not be credible. PRIOR 7 PRELIMINARY WORK: We have developed theoretical models for (1) the thermal noise limit for the response of cells to an electric field, (2) electroconformational coupling of membrane enzymes, (3) electroporation- related phenomena, and have preliminary results for (4) a model for altered molecular protrusion, and (5) the threshold for a magnetic interaction for soluble intracellular molecules. METHODS: We will treat cellular subsystems which can be plausibly represented by a physical model, and which provide a possible coupling to one or more biochemical pathways. Modeling of interactions with external electromagnetic fields will be developed, with an emphasis on predicting the dependence on key parameters. Our primary hypothesis involves electroconformation changes of membrane entities (membrane macromolecules, the membrane itself, and membrane/macromolecule complexes). Our secondary hypothesis involves soluble intracellular molecules (e.g., DNA), and possible intracellular magnetic interactions through induced electric fields. Biological background fields and intrinsic noise will be combined with theoretical models to estimate thresholds for bioelectromagnetic effects.