Original articles
GAO Xinlong, HE Ying, WU Wenhui, MIN Tianjiao, LIU Lina, JIANG Beier
Objective To study the mechanism by which acoustic wave stimulation improves cognitive function in sleep-deprived mice. Methods （1） Thirty-six male C57BL/6 mice were randomly divided into three groups： the control group,model group and acoustic wave group （n=12 per group）. A sleep deprivation model was established using the modified multiple platform method. After 21 days of sleep deprivation in a row,mice in the acoustic wave group were exposed to 30-minute acoustic wave stimulation at 40 dB. （2） During sleep deprivation, the health status of each group of mice was recorded, including the mental state and body weight. （3） After 21 days of sleep deprivation, behavioral tests （open field test, novel object recognition test, Y-maze and Morris water maze） were performed to assess the spontaneous activity, spatial exploration, and such cognitive functions as learning and memory in mice. Immunohistochemistry was conducted to analyze the expressions of neuronal nuclear antigen （NeuN）, glial fibrillary acidic protein （GFAP） and ionized calcium-binding adaptor molecule 1 （Iba-1）in the hippocampus. Quantitative real-time PCR （qPCR） was used to measure the expression levels of interleukin-6 （IL-6）, tumor necrosis factor-alpha （TNF-α） and inducible nitric oxide synthase （iNOS） in the hippocampus. （4） Transcriptome sequencing was employed to explore the mechanism underlying the improvement of cognitive impairment by acoustic wave stimulation. Results After 21 days of sleep deprivation, acoustic wave stimulation significantly alleviated weight loss in mice （P<0.01）. The accuracy of Y-maze spontaneous alternation, indexes of novel object discrimination, the time spent in the target quadrant and the number of times the mice crossed the platformin the Morris water maze were all significantly increased （P<0.05）, while the escape latency was significantly reduced （P<0.05）. The average optical density of NeuN in the hippocampal CA3 region significantly increased （P<0.05）, GFAP and Iba-1 immunopositive cell counts significantly decreased （P<0.01）, and the mRNA levels of IL-6, TNF-α, and iNOS in the hippocampal tissue were significantly reduced （P<0.05）. Conclusion Acoustic wave stimulation can repair neural damage, modulate hippocampal inflammatory responses, and improve cognitive deficits induced by sleep deprivation.
