Scientists recently conducted a series of studies to test the biosafety and neurobehavioral effects of 33.0 Tesla static high magnetic fields (SMFs) using the Steady High Magnetic Field Facility’s (SHMFF) improvised biological research platform. The experiments were carried out by Professor Xin Zhang’s group at the Hefei Institutes of Physical Science of the Chinese Academy of Sciences. For the first time, they reported the biosafety of 30 Tesla SMF and the neurobehavioral effects of 20 Tesla and 30 Tesla SMF in healthy mice in the Journal of Magnetic Resonance Imaging and European Radiology. In recent years, ultrahigh-field magnetic resonance imaging (MRI) has developed rapidly due to the significant advantage of high imaging resolution. 7 Tesla MRI has been clinically approved and 21.1 Tesla MRI has been successfully used in rodents. However, biosafety studies of high magnetic fields above 20 Tesla are still rare, and there is still a gap in relevant studies above 30 Tesla. Based on the previous biosafety study of the 3.5-23.0 Tesla SMF, Xin Zhang’s team further increased the magnetic field strength and reduced the exposure time. Healthy C57BL/6J mice were exposed to 7.0-33.0 Tesla SMF for one hour. Experiments performed at SHMFF. Credit: Yue Lyu After exposure, all mice were fed regularly for two months. Except for a few markers of metabolic and liver and hepatorenal function that were affected by the magnetic field, the whole blood count and the organ factor in 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 relieved anxiety and improved social and spatial memory in mice within two months of exposure. In addition, behavioral studies of healthy mice exposed to a magnetic field of 3.5-23.0 Tesla for two hours also found improved neurocognitive outcomes, which may be related to increased expression of calcium/calmodulin-dependent protein kinase II in the mouse hippocampus . Zhang’s team further found that 7 Tesla SMF could effectively relieve the symptoms of depressed mice. These results not only provide useful safety information for the development of ultrahigh 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, March 16, 2022, European Radiology.DOI: 10.1007/s00330-022-08677-8 This study was supported by the National Research and Development Program of the Ministry of Science and Technology, the National Natural Science Foundation of China, the Presidential Fund of Hefei Institutes of Natural Science, etc.
