Original articles
ZHANG Mingzhao, YANG Zhenqi, ZOU Yong, MA Lizhen, ZHI Weijia, NIU Jiajia, DONG Ji, HU Xiangjun, WANG Lifeng
Objective To investigate the effects of intermittent microwave irradiation on pathological structure and cognitive function of Alzheimer’s disease （AD） mice. Methods Forty C57BL/6J mice and another forty 5×FAD mice were randomly divided into the sham irradiation （sham-WT）,irradiation （MW-WT）,AD sham irradiation （sham-AD）,and AD irradiation （MW-AD） groups,with 20 mice in each. Mice underwent daily 1-hour microwave irradiation （900 MHz,40 Hz repetition rate） on an intermittent schedule： 2 weeks on,2 weeks off,and 2 weeks on again. The cognitive function of mice was assessed via behavioral experiments conducted both immediately and six weeks after irradiation. The expressions of phosphorylated tau（p-Tau） and β amyloid protein （Aβ） plaques were detected via immunofluorescence. Enzyme-linked immunosorbent assay （ELISA） was used to detect the levels of key enzymes involved in Aβ production and neuroinflammatory factors in the brain tissue. Results Compared with the sham-WT group,the novel object recognition index and the novel arm recognition index in the sham-AD group were significantly reduced（P<0.05）, but those were significantly increased in the MW-AD group compared to the sham-AD group （P<0.05）. In addition,the levels of p-Tau and Aβ proteins in the brain of the MW-AD group were significantly decreased （P<0.05） while the levels of β-secretase and γ-secretase in the cortex were significantly increased （P<0.05）. The levels of CD68,tumor necrosis factor-α （TNF-α）,and interleukin-10 （IL-10） were also increased to varying degrees （P<0.05）. Conclusion Intermittent microwave irradiation （900 MHz,40 Hz） can ameliorate cognitive deficits and attenuate Aβ and p-Tau pathology in AD mice rather than inhibit the key secretases involved in Aβ production or the occurrence of neuroinflammation.
