Scientists recently conducted a series of studies to test the biosafety and neurobehavioral effects of 33.0 Tesla strong static magnetic fields (SMF) using the self-designed Steady High Magnetic Field Facility (SHMFF) biological research platform. The experiments were carried out by Prof. Xin Zhang’s team at the Hefei Institutes of Physics of the Chinese Academy of Sciences.
They first reported the biosafety of 30 Tesla SMF and the neurobehavioral effects of 20 Tesla and 30 Tesla SMF on healthy mice in Journal of Magnetic Resonance Imaging and European Radiology.
In recent years, ultrahigh-field magnetic resonance imaging (MRI) has developed rapidly due to its significant advantage of high imaging resolution. 7 Tesla MRI is clinically approved and 21.1 Tesla MRI has been successfully used in rodents. However, studies on the biosafety of strong magnetic fields above 20 Tesla are still scarce, and there is still a gap in relevant studies above 30 Tesla.
Based on the previous biosafety study of 3.5-23.0 Tesla SMF, Xin Zhang’s group further increased the magnetic field intensity and shortened the exposure time. Healthy C57BL/6J mice were exposed to 7.0-33.0 Tesla SMF for one hour.
After exposure, all mice were routinely fed for two months. Except for a few metabolic and liver and hepatorenal function parameters affected by the magnetic field, the general blood count and the organ coefficient on the histomorphology of the main organs were not seriously affected, most of the mice remained within the normal reference range.
Meanwhile, behavioral tests showed that high SMF alleviated anxiety and improved social and spatial memory in mice within two months of exposure.
Additional, Behavioral studies of healthy mice exposed to a magnetic field of 3.5-23.0 Tesla for two hours also found enhanced neurocognitive effects that may be associated with increased expression of calcium/calmodulin-dependent protein kinase II in the hippocampus of the mouse.
In addition, Zhang’s group found that a 7 Tesla SMF could effectively relieve the symptoms of depressed mice. These results not only provide useful safety information for the development of ultra-high MRI, but may also indicate that high SMF has the potential to be a future antidepressant treatment.
Reference: “Short-term and long-term effects of ultrahigh magnetic fields 3.5-23.0 Tesla on the behavior of mice” by Md Hasanuzzaman Khan, Xinfeng Huang, Xiaofei Tian, Changjie Ouyang, Dongmei Wang, Shuang Feng, Jutao Chen , Tian Xue, Jin Bao and Xin Zhang, 16 Mar 2022, European Radiology.
This study was supported by the National Key Research and Development Program of the Ministry of Science and Technology, the National Natural Science Foundation of China, the Presidential Fund of the Hefei Institutes of Physics, etc.