眼非视觉功能在生物感磁过程中的作用

Research progress on the role of non-image forming functions of eyes in magnetoreception of organisms

眼的非视觉功能包括生物昼夜节律的调节以及生物感磁。生物感磁是指各种生物包括人类可通过地磁场获取方向位置信息。具有视网膜结构的生物可能是以视网膜隐花色素蛋白作为磁受体,完成生物感磁过程。生物感磁的假说分别是基于化学反应和自由基对的磁感应假说以及光磁耦合的生物指南针假说。这2个假说都认为视网膜上的分子可能是生物感磁的受体蛋白,眼可能是生物感磁的器官。但基于化学反应和自由基对的磁感应假说认为是通过自由基电子自旋方式的改变,影响了视网膜隐花色素蛋白的分子结构,引起下游化学反应产生不同的化学产物,从而感受到磁场的变化;光磁耦合的生物指南针假说指出隐花色素蛋白作为光受体,与另一种磁受体蛋白经过多聚反应形成棒状小体,光信号和磁信号的耦合影响了棒状的复合体指向的变化。这些视网膜上的改变再通过某种途径传输至大脑,从而产生方向感。研究生物感磁有助于从新的角度诊断和治疗眼脑疾病,并且带来磁敏材料领域的革新。本文就眼非视觉功能、生物感磁过程的机制假说和眼非视觉功能在生物感磁过程中可能的作用机制进行综述。

Non-image forming functions of eyes include the regulation of biological circadian rhythm and biological magnetoreception.Biological magnetoreception means that various organisms including human obtain the direction and position information through the geomagnetic field.Creatures with retina realize magnetoreception regarding retinal cryptochrome as magnetoreceptor.Hypotheses of magnetoreception contain the radical-pair theory and the biological compass theory.The two theories both reckon retinal elements as possible receptor protein of magnetoreception,and eyes as receptor organ.The radical-pair theory suggests that change of radical spin influences the structure of retinal cryptochrome,leading to different downstream chemical reaction products,which makes the variable magnetic field information perceivable.And the biological compass theory proposes a rod-like complex composed of polymerized cryptochromes and magnetoreceptor proteins,which can point to different directions due to light and magnetic signals.These changes in retina transmit geomagnetic field signal to the brain,and then sense of direction is formed.Researching biological magnetoreception promotes a novel perspective in the diagnosis and treatment of eye and brain diseases,and brings innovation in magnetic material field.In this article,non-image forming functions of eyes,hypotheses of magnetoreception and possible mechanism of non-image forming functions of eyes in magnetoreception were reviewed.