Scientists recently conducted a series of studies to test the biosafety and neurobehavioral effects of 33.0 Tesla high static magnetic fields (SMF) using the self-designed biological research platform of Steady High Magnetic Field Facility (SHMFF). The experiments were performed by Prof. Xin Zhang’s team at the Hefei Institutes of Physical Science of the Chinese Academy of Sciences.
They, for the first time, reported the biosafety of 30 Tesla level SMF and the neurobehavioral effects of 20 Tesla and 30 Tesla level SMF on healthy mice in the Journal of Magnetic Resonance Imaging and European Radiology.
In recent years, ultra-high field magnetic resonance imaging (MRI) has developed rapidly due to its 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, studies on the biosafety of high 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 indicators affected by the magnetic field, the whole blood count and organ coefficient on histomorphology of 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 after exposure.
In addition, Behavioral studies of healthy mice exposed to a 3.5-23.0 Tesla magnetic field for two hours also found improved neurocognitive effects, which may be associated with increased calcium/calmodulin-dependent protein kinase II expression in the mouse hippocampus.
Zhang’s group further found that 7 Tesla SMF could effectively relieve 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- and long-term effects of 3.5–23.0 Tesla ultra-high magnetic fields on mice behavior” by Md Hasanuzzaman Khan, Xinfeng Huang, Xiaofei Tian, Changjie Ouyang, Dongmei Wang, Shuang Feng, Jutao Chen, Tian Xue, Jin Bao and Xin Zhang, 16 March 2022, European Radiology.
This study was supported by the National Key Research & Development Program of Ministry of Science and Technology, the National Natural Science Foundation of China, the President’s Fund of Hefei Institutes of Physical Science, etc.