Radical pair Mechanism as a potential quantum mechanical explanation for superoxide-mediated low-intensity magnetic field effects in biology

Exposures to weak magnetic fields, including hypomagnetic ones, can affect several biological processes across various living systems. Despite hundreds of experimental studies, the underlying physical basis for these effects still needs to be understood. The energies associated with these magnetic fields are far smaller than thermal energies at biologically relevant temperatures rendering any obvious classical explanation highly improbable. The radical pair mechanism (RPM) has been proposed as a quantum mechanical explanation for many of these magnetically sensitive phenomena, such as avian magnetoreception. An RPM is an inherently quantum chemical mechanism in which a pair of radicals are created simultaneously, such that the spins on the two electrons, one on each radical, evolve coherently. In many of these processes, it has been observed that magnetic field effects act via the changes in reactive oxygen species, mainly superoxide. This presentation will discuss radical pair mechanisms based on flavin-superoxide radical pair as a potential explanation for two such phenomena, namely, detrimental effects of hypomagnetic field on adult hippocampal neurogenesis in mice and magnetic field effects on stem cell-mediated growth in planaria.