Photobiomodulation using low-level light-emitting diode can be rapidly applied in neurological and physiological disorders safely and noninvasively. Photobiomodulation is effective for chronic diseases because of fewer side effects than drugs. Here we investigated the effects of photobiomodulation using light-emitting diode on amyloid plaques, gliosis, and neuronal loss to prevent and/or recover cognitive impairment, and optimal timing of photobiomodulation initiation for recovering cognitive function in a mouse model of Alzheimer’s disease. 5XFAD mice were used as an Alzheimer’s disease model. Animals receiving photobiomodulation treatment were divided into two groups: an early group starting photobiomodulation at 2 months of age (5XFAD+Early), and a late group starting photobiomodulation at 6 months of age (5XFAD+Delay). Both groups received photobiomodulation 20 minutes per session three times per week for 14 weeks. The Morris water maze, passive avoidance, and elevated plus maze tests were performed at 10 months of age. Immunohistochemistry and Western blot were performed after behavioral evaluation. The results showed that photobiomodulation treatment at early stages reduced amyloid accumulation, neuronal loss, and microgliosis and alleviated the cognitive dysfunction in 5XFAD mice, possibly by increasing insulin degrading enzyme related to amyloid-beta degradation. Photobiomodulation may be an excellent candidate for advanced preclinical Alzheimer’s disease research.

中文翻译：

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使用低水平发光二极管的光生物调节改善阿尔茨海默氏病的5XFAD小鼠模型中的认知功能障碍。

使用低级发光二极管的光生物调节可以安全，无创地快速应用于神经和生理疾病。光生物调节对慢性疾病有效，因为其副作用比药物少。在这里，我们调查了使用发光二极管进行光生物调节对淀粉样斑块，神经胶质和神经元丢失的预防和/或恢复认知障碍的作用，以及在阿尔茨海默病小鼠模型中光生物调节开始以恢复认知功能的最佳时机。将5XFAD小鼠用作阿尔茨海默氏病模型。接受光生物调节治疗的动物分为两组：早期组在2个月大时开始光生物调节（5XFAD + Early），晚期组在6个月大时开始光生物调节（5XFAD + Delay）。两组均每疗程20分钟接受光生物调节，每周3次，共14周。在10个月大时进行了莫里斯水迷宫，被动回避和高架迷宫测试。行为评估后进行免疫组织化学和蛋白质印迹。结果表明，在早期进行光生物调节治疗可减少5XFAD小鼠的淀粉样蛋白积累，神经元丢失和小胶质细胞增生，并减轻认知功能障碍，这可能是通过增加与β-淀粉样蛋白降解相关的胰岛素降解酶来实现的。光生物调节可能是高级临床前阿尔茨海默氏病研究的极佳候选者。行为评估后进行免疫组织化学和蛋白质印迹。结果表明，在早期进行光生物调节治疗可减少5XFAD小鼠的淀粉样蛋白积累，神经元丢失和小胶质细胞增生，并减轻认知功能障碍，这可能是通过增加与β-淀粉样蛋白降解相关的胰岛素降解酶来实现的。光生物调节可能是先进的临床前阿尔茨海默氏病研究的极佳候选者。行为评估后进行免疫组织化学和蛋白质印迹。结果表明，在早期进行光生物调节治疗可减少5XFAD小鼠的淀粉样蛋白积累，神经元丢失和小胶质细胞增生，并减轻认知功能障碍，这可能是通过增加与β-淀粉样蛋白降解相关的胰岛素降解酶来实现的。光生物调节可能是先进的临床前阿尔茨海默氏病研究的极佳候选者。