Effects of low frequency magnetic stimulation on myelin and inflammation in demyelinated mice / 中华物理医学与康复杂志

ABSTRACT

Objective:To explore the effect of low frequency magnetic stimulation on myelin and inflammation in the callosum of demyelinated mice.Methods:Thirty-six 6 to 8-week-old male C57BL/6J mice were randomly divided into a control group, a cuprizone (CPZ) group and a magnetic therapy group. The CPZ group and the magnetic therapy group had demyelination induced by feeding a mixed diet containing 0.3% CPZ for 6 weeks, while the control group was given conventional food. The magnetic therapy group was given 50Hz 10mT magnetic stimulation during the 6 weeks for 20min daily, 5 days a week. The body mass of each mouse was observed every 7 days. At the end of the 6th week elevated cross maze experiments were conducted to observe any anxiety state. The myelin sheath in the corpus callosum was observed using Luxol fast blue staining and myelin basic protein (MBP) immunohistochemistry Tumor necrosis factor-α (TNF-α) and interleukin-1β (IL-1β) in the corpus callosum were detected using enzyme-linked immunosorbent assays.Results:After the 6 weeks of treatment, the average body mass of the mice in the magnetic therapy group had improved significantly compared with the CPZ group. The CPZ group′s times in the elevated cross maze experiments were significantly shorter than those of the control group and also shorter than those of the magnetic therapy group. The Luxol staining showed significant myelin loss in the corpus callosum of the CPZ group, but compared with the CPZ group the average loss of myelin in the magnetic therapy group was significantly less. This was further confirmed by the MBP immunohistochemistry. Compared with the control group, the average expression of MBP in the CPZ group was significantly reduced, while in the magnetic therapy group it was significantly increased. Compared with the control group, the average TNF-α and IL-1β levels in the corpus callosum of the CPZ group increased significantly, but compared with the CPZ group the average levels in the magnetic therapy group had decreased significantly.Conclusions:Low frequency magnetic stimulation improves the body weight and anxiety state of mice. That is probably related to less myelin loss and inhibited inflammatory response in the corpus callosum.