Liboff A R, McLeod B R
Department of Physics, Oakland University, Rochester, MI 48309-4401.
Bioelectromagnetics. 1988;9(1):39-51. doi: 10.1002/bem.2250090104.
The cyclotron resonance model for channel ion transport in weak magnetic fields is extended to include damping losses. The conductivity tensor is obtained for different electric field configurations, including the circuital field E phi normal to the channel axis. The conductivity behavior close to the cyclotron resonance frequency omega c is compared to existing Ca2+-efflux data in the literature. A collision time of .023 s results from this comparison under the assumption that K+ ions are transiting in a 0.35 G field. We estimate a mean kinetic energy of 3.5 eV for this ion at resonance. This model leads to discrete modes of vibration (eigenfrequencies) in the ion-lattice interaction, such that omega n = n omega c. The presence of such harmonics is compatible with recent results by Blackman et al. [1985b] and McLeod et al. [1986] with the interesting exception that even modes do not appear in their observations, whereas the present model has no restriction on n. This harmonic formalism is also consistent with another reported phenomenon, that of quantized multiple conductances in single patch-clamped channels.
弱磁场中通道离子输运的回旋共振模型被扩展到包括阻尼损耗。针对不同的电场配置，包括垂直于通道轴的圆周场(E_{\phi})，得到了电导率张量。将接近回旋共振频率(\omega_c)的电导率行为与文献中现有的钙外流数据进行了比较。在假设钾离子在(0.35G)场中跃迁的情况下，通过这种比较得出的碰撞时间为(0.023s)。我们估计该离子在共振时的平均动能为(3.5eV)。该模型导致离子 - 晶格相互作用中存在离散的振动模式（本征频率），使得(\omega_n = n\omega_c)。这种谐波的存在与布莱克曼等人[1985b]和麦克劳德等人[1986]的最新结果一致，但有趣的是，他们的观测中没有出现偶次模式，而本模型对(n)没有限制。这种谐波形式主义也与另一个报道的现象一致，即单膜片钳通道中的量子化多电导现象。
