Kirschvink J L, Kobayashi-Kirschvink A, Diaz-Ricci J C, Kirschvink S J
Division of Geological and Planetary Sciences, California Institute of Technology, Pasadena 91125.
Bioelectromagnetics. 1992;Suppl 1:101-13. doi: 10.1002/bem.2250130710.
Due to the apparent lack of a biophysical mechanism, the question of whether weak, low-frequency magnetic fields are able to influence living organisms has long been one of the most controversial subjects in any field of science. However, two developments during the past decade have changed this perception dramatically, the first being the discovery that many organisms, including humans, biochemically precipitate the ferrimagnetic mineral magnetite (Fe3O4). In the magnetotactic bacteria, the geomagnetic response is based on either biogenic magnetite or greigite (Fe3S4), and reasonably good evidence exists that this is also the case in higher animals such as the honey bee. Second, the development of simple behavioral conditioning experiments for training honey bees to discriminate magnetic fields demonstrates conclusively that at least one terrestrial animal is capable of detecting earth-strength magnetic fields through a sensory process. In turn, the existence of this ability implies the presence of specialized receptors which interact at the cellular level with weak magnetic fields in a fashion exceeding thermal noise. A simple calculation shows that magnetosomes moving in response to earth-strength ELF fields are capable of opening trans-membrane ion channels, in a fashion similar to those predicted by ionic resonance models. Hence, the presence of trace levels of biogenic magnetite in virtually all human tissues examined suggests that similar biophysical processes may explain a variety of weak field ELF bioeffects.
由于明显缺乏生物物理机制，弱的低频磁场是否能够影响生物体这一问题长期以来一直是任何科学领域中最具争议性的课题之一。然而，在过去十年中的两项进展极大地改变了这种看法，第一个进展是发现包括人类在内的许多生物体能够通过生化作用沉淀出亚铁磁性矿物磁铁矿（Fe3O4）。在趋磁细菌中，地磁响应基于生物源磁铁矿或硫复铁矿（Fe3S4），并且有相当充分的证据表明在诸如蜜蜂等高等动物中也是如此。其次，用于训练蜜蜂辨别磁场的简单行为条件实验的发展确凿地证明，至少有一种陆生动物能够通过感官过程检测到地磁场强度的磁场。反过来，这种能力的存在意味着存在专门的受体，这些受体在细胞水平上以超过热噪声的方式与弱磁场相互作用。一个简单的计算表明，响应地磁场强度的极低频场而移动的磁小体能够以类似于离子共振模型所预测的方式打开跨膜离子通道。因此，在几乎所有检测过的人体组织中都存在痕量水平的生物源磁铁矿，这表明类似的生物物理过程可能解释各种弱场极低频生物效应。
