急性应激对小鼠焦虑样和抑郁样行为及皮层脑电活动的影响OA

OBJECTIVE To investigate the effects of acute stress on anxiety-and depression-like behaviors in mice and characterize changes in cortical electroencephalographic activity during the early phase after acute stress exposure.METHODS ① Adult male C57BL/6J mice were randomly assigned to a control group and stress group.The stress group received a single 2 h water immersion restraint stress(WIRS)while the control group fasted but was allowed water access during the same period.After stress treatment,mice were dried and allowed to restore their body temperature under a warm lamp for 30 min.The open field test and elevated plus maze were used to assess spontaneous locomo-tion,exploratory behavior,and anxiety-like behavior.The tail suspension test and forced swim test were conducted to evaluate depression-like behavior.The rotarod test was performed to assess motor function.② Mice were randomly divided into control and stress groups,with stress and recovery proce-dures identical to ①.Serum corticosterone(CORT)levels were measured by ELISA at 0,30,60,and 180 min after stress.③ A 16-channel flexible electrode array was implanted 10 days before experi-ments.After 7 days of postoperative recovery and 3 days of habituation to the recording environment,mice were randomly assigned to control and stress groups.Stress and recovery protocols followed ①.In vivo electrophysiology was conducted to monitor cortical electroencephalographic activity,and power spectral density(PSD)was analyzed across frequency bands.RESULTS ① No differences were observed between the stress and control groups in body temperature,mean velocity,falling speed,or latency to fall.Compared with the control group,significantly reduced time spent in the center,fewer entries into the center,decreased total distance travelled,less time spent in the open arms,fewer open-arm entries,and significantly prolonged immobility times in both the tail suspension test and forced swim test were observed among the stress mice.② Biochemical results showed that serum CORT levels in the stress group were significantly higher than those of controls at 30,60,and 180 min post-stress,but not at 0 minute.③ Electrophysiological data revealed that,compared with control group,the stress group displayed significantly increased PSD in the high-beta and low-gamma bands in the left caudomedial entorhinal cortex(L-CEnt),significantly decreased PSD across all frequency bands in the left secondary auditory cortex dorsal region(L-AuD),significantly reduced PSD in the 50-170 Hz gamma band in the left prefrontal association cortex(L-FrA),and significantly elevated PSD in the 150-200 Hz gamma band in the right prefrontal association cortex(R-FrA).CONCLUSION WIRS can induce anxiety-and depression-like behaviors in mice,accompanied by elevated serum CORT levels and specific alter-ations in neural oscillations in the L-CEnt,L-AuD,L-FrA,and R-FrA.