Department of Neuroscience and Regenerative Medicine, Medical College of Georgia, Augusta University, Augusta, GA, USA.
Department of Discovery and Biomedical Sciences College of Pharmacy, University of South Carolina, Columbia, SC, USA.
J Alzheimers Dis. 2021;83(4):1415-1429. doi: 10.3233/JAD-201616.
Anxious-depressive-like behavior has been recognized as an early endophenotype in Alzheimer's disease (AD). Recent studies support early treatment of anxious-depressive-like behavior as a potential target to alleviate memory loss and reduce the risk of developing dementia. We hypothesize that photobiomodulation (PBM) could be an effective method to alleviate depression and anxiety at the early stage of AD pathogenesis.
To analyze the effect of PBM treatment on anxious-depressive-like behavior at the early stage of AD.
Using a novel transgenic AD rat model, animals were divided into wild-type, AD+sham PBM, and AD+PBM groups. Two-minute daily PBM (irradiance: 25 mW/cm2 and fluence: 3 J/cm2 at the cortical level) was applied transcranially to the brain of AD animals from 2 months of age to 10 months of age. After completing PBM treatment at 10 months of age, behavioral tests were performed to measure learning, memory, and anxious-depressive-like behavior. Neuronal apoptosis, neuronal degeneration, neuronal damage, mitochondrial function, neuroinflammation, and oxidative stress were measured to test the effects of PBM on AD animals.
Behavioral tests showed that: 1) no spatial memory deficits were detected in TgF344 rats at 10 months of age; 2) PBM alleviated anxious-depressive-like behavior in TgF344 rats; 3) PBM attenuated neuronal damage, degeneration, and apoptosis; and 4) PBM suppresses neuroinflammation and oxidative stress.
Our findings support our hypothesis that PBM could be an effective method to alleviate depression and anxiety during the early stage of AD development. The mechanism underlying these beneficial effects may be due to the improvement of mitochondria function and integrity and the inhibition of neuroinflammation and oxidative stress.
焦虑抑郁样行为已被认为是阿尔茨海默病（AD）的早期内表型。最近的研究支持早期治疗焦虑抑郁样行为作为减轻记忆丧失和降低痴呆风险的潜在靶点。我们假设光生物调节（PBM）可能是一种缓解 AD 发病早期抑郁和焦虑的有效方法。
分析 PBM 治疗对 AD 早期焦虑抑郁样行为的影响。
使用新型转基因 AD 大鼠模型，将动物分为野生型、AD+假 PBM 和 AD+PBM 组。从 2 个月大到 10 个月大，每天对 AD 动物进行 2 分钟的 PBM（皮层水平的辐照度：25 mW/cm2，剂量：3 J/cm2）。在 10 个月大完成 PBM 治疗后，进行行为测试以测量学习、记忆和焦虑抑郁样行为。测量神经元凋亡、神经元变性、神经元损伤、线粒体功能、神经炎症和氧化应激，以测试 PBM 对 AD 动物的影响。
行为测试表明：1）TgF344 大鼠在 10 个月大时没有检测到空间记忆缺陷；2）PBM 缓解了 TgF344 大鼠的焦虑抑郁样行为；3）PBM 减轻了神经元损伤、变性和凋亡；4）PBM 抑制了神经炎症和氧化应激。
我们的研究结果支持我们的假设，即 PBM 可能是缓解 AD 发病早期抑郁和焦虑的有效方法。这些有益效果的机制可能是由于改善了线粒体功能和完整性，抑制了神经炎症和氧化应激。
