Calcium and Potassium Cyclotron Resonance Curves and Harmonics in Diatoms (A. Coeffeaformis)

Abstract

Our previous findings provide strong evidence that transport of a given ionic species through a cell membrane can be precisely controlled by tuning externally applied magnetic fields to the ion cyclotron resonance (CR) gyrofrequency for the ion in question. Experiment and theory have shown that certain odd harmonics of the fundamental resonance frequency are also effective. In the present experiment we again used the model of Ca-dependent motility of benthic diatoms, extending our harmonic studies through N = 17, for both Ca²⁺ and K⁺ fundamentals. Eight separate Ca2⁺ fundamental frequencies: 8, 12, 16, 23, 31, 32, 46, 64 Hz were attempted and each was found to obey the CR condition. We also report two observations: (1) tuning to K⁺ results in inhibition of motility, directly opposite to the enhancement that occurs when tuning for Ca2⁺; (2) both the K⁺ inhibition and Ca²⁺ enhancement are independently observed at exactly the same harmonics: N = 1, 3, 5, 15. This strongly suggests that despite differences in ionic selectivity, K⁺ and Ca²⁺ channels may share fundamentally similar protein configurations.