Intermittent ELF-MF exposure effectively ameliorates pathologic features associated with adult AD mice.

OBJECTIVE

Extremely low frequency magnetic fields (ELF-MF) have been confirmed to have potentially positive effects on Alzheimer's disease (AD). However, the therapeutic effects are influenced by the exposure mode and the pathological process. Currently, there is no optimized treatment plan for the pathological process of AD. This study aims to optimize the exposure mode of ELF-MF to improve the therapeutic effect on AD mice with different degrees of dementia.

METHOD

This study employed 40 Hz, 10mT continuous pulsed ELF-MF stimulation, intermittent (stimulating for 30 min every 12 h) and continuous (stimulating for 60 min every 24 h) ELF-MF exposure. Through calculating various behavioral data, the changes in spatial working memory (SWM) of each group of mice were compared; the time-frequency distribution analysis method was applied to compare the changes in the theta band and gamma band neural oscillations of local field potentials (LFPs) signals in the CA1 region of the hippocampus during the object location task (OLT) of each group of mice; by analyzing the immunofluorescence images of Amyloid-beta 42 (Aβ) and dynamin-related protein 1 (Drp1) in the hippocampal region of each group of mice, the changes in Aβ and Drp1 contents were compared.

RESULTS

ELF-MF stimulation can improve the SWM ability of AD model mice. Among them, intermittent stimulation in the adult group shows a better effect, while continuous stimulation in the aged group is superior. Further LFPs analysis reveals that AD leads to a decrease in theta and gamma frequency band energy in the CA1 area of the hippocampus, while ELF-MF stimulation can significantly enhance its energy. Moreover, in the adult group, the improvement of theta and gamma frequency bands under intermittent stimulation is more obvious, and in the aged group, the improvement of theta frequency band under continuous stimulation is more significant. The results of immunofluorescence detection indicate that ELF-MF stimulation can reduce the abnormal accumulation of Aβ and Drp1 in the hippocampus, and the effect of intermittent stimulation in the adult group is more significant.

CONCLUSION

Intermittent ELF-MF exposure may be an effective therapeutic strategy, especially in adult AD mice. This study highlights the potential significance of the ELF-MF exposure pattern in AD treatment and reveals the heterogeneous effects of ELF-MF exposure on the physiological and pathological conditions of AD mice, which has important guiding significance for the formulation of personalized treatment plans in the future.