中缝核NG2细胞及5-HT的共同作用对大鼠睡眠-觉醒功能的调节

NG2 cells and 5-HT in raphe nuclei have combined effect on regulation of sleep-wake function in rats

目的:探究中缝核NG2胶质细胞及5-羟色胺(5-HT)的共同作用对大鼠睡眠-觉醒功能的影响。方法:将70只SD大鼠随机分成正常组、空白组、神经元-胶质细胞抗原2(NG2)单克隆抗体(NG2-Ab)组、对氯苯丙氨酸(PCPA)组、5-HT组、NG2-Ab+PCPA组及NG2-Ab+5-HT组,每组10只。正常组大鼠不做任何处理;对其他6组大鼠进行脑电图(EEG)和肌电图(EMG)记录电极及微量注射套管的埋置。恢复7 d后,对各组大鼠进行24 h的EEG/EMG信号记录。正常组大鼠不给予任何药物,向其他各组大鼠中缝核内分别微量注射药物:(1)空白对照组大鼠微量注射1μL生理盐水;(2)NG2-Ab组大鼠微量注射1μL NG2-Ab溶液(5 g/L);(3)PCPA组大鼠微量注射1μL PCPA溶液(10 g/L);(4)5-HT组大鼠微量注射1μL 5-HT溶液(2.5 g/L);(5)NG2-Ab+PCPA组大鼠微量注射1μL PCPA溶液(10 g/L)和1μL NG2-Ab溶液(5 g/L);(6)NG2-Ab+5-HT组大鼠微量注射1μL 5-HT溶液(2.5 g/L)和1μL NG2-Ab溶液(5 g/L),连续给药2 d。末次给药2 h后再次记录各组大鼠的EEG/EMG信号,连续记录72 h。结果:与给药前1 d相比,NG2-Ab组和PCPA组大鼠的觉醒(W)时间在给药后显著延长(P<0.05),非快眼动睡眠(NREMS)、快眼动睡眠(REMS)及总睡眠(TS)时间在给药后显著缩短(P<0.05);5-HT组大鼠的W时间在给药后显著缩短(P<0.05),NREMS、REMS及TS时间在给药后显著延长(P<0.05)。与PCPA组相比,NG2-Ab+PCPA组大鼠的W时间在给药后显著缩短(P<0.05),NREMS、REMS及TS时间在给药后均显著延长(P<0.05)。与5-HT组相比,NG2-Ab+5-HT组大鼠的W时间在给药后显著延长(P<0.05),NREMS、REMS及TS时间在给药后均显著缩短(P<0.05)。与空白对照组相比,NG2-Ab组大鼠的EEG波形特征在给药后无明显变化;PCPA组大鼠δ波百分比在给药后显著增加(P<0.05),α波和β波百分比在给药后均显著减少(P<0.05);5-HT组大鼠的EEG波形特征在给药后无明显变化。与PCPA组相比,NG2-Ab+PCPA组大鼠δ波百分比在给药后显著减少(P<0.05)。与5-HT组相比,NG2-Ab+5-HT组大鼠β波百分比在给药后显著增加(P<0.05)。结论:中缝核NG2细胞及NG2细胞与5-HT的共同作用能够调节大鼠的睡眠-觉醒时间及EEG活动。

AIM:To investigate the combined effects of NG2 cells and 5-hydroxytryptamine(5-HT)in raphe nuclei on the sleep-wake function in rats.METHODS:Sprague-Dawley rats(n=70)were randomly divided into normal group,control group,para-chlorophenylalanine(PCPA)group,anti-neuron-glial antigen 2(NG2)monoclonal antibody(NG2-Ab)group,5-HT group,NG2-Ab+PCPA group and NG2-Ab+5-HT group,with 10 rats in each group. The rats innormal group did not receive any treatment. The rats in other 6 groups were implanted with electrodes and microinjection needles for recording electroencephalogram(EEG)and electromyogram(EMG). After 7 d of recovery,EEG and EMG signals in each group were recorded for 24 h. The rats in each group were microinjected with respective drugs in raphe nuclei:(1)The normal rats were not given any drugs.(2)The rats in control group were microinjected with 1 μL of normal saline.(3)The rats in NG2-Ab group were injected with 1 μL of NG2-Ab solution(5 g/L).(4)The rats in PCPA group were microinjected with 1 μL of PCPA solution(10 g/L).(5)The rats in 5-HT group were injected with 1 μL of 5-HT solution(2. 5 g/L).(6)The rats in NG2-Ab+PCPA group were injected with 1 μL of PCPA solution(10 g/L)and 1 μL of NG2-Ab solution(5 g/L).(7)The rats in NG2-Ab+5-HT group were injected with 1 μL of 5-HT solution(2. 5 g/L)and 1μL of NG2-Ab solution(5 g/L). The rats in each group were treated for 2 consecutive days. The EEG and EMG signals of the rats in each group were recorded again for 72 h continuously after administration.RESULTS:Compared with 1 d before administration,the wake(W)durations in NG2-Ab group,PCPA group and NG2-Ab+PCPA group were increased after administration(P<0. 05),while the durations of non-rapid eye movement sleep(NREMS),rapid eye movement sleep(REMS)and total sleep(TS)were decreased after administration(P<0. 05). The W duration in 5-HT group was decreased after administration(P<0. 05),while the NREMS,REMS and TS durations were increased after administration(P<0. 05). Compared with PCPA group,the W duration in NG2-Ab+PCPA group was decreased(P<0. 05),while the durations of NREMS,REMS and TS were increased after administration(P<0. 05). Compared with 5-HT group,the W duration in NG2-Ab+5-HT group was increased after treatment(P<0. 05),while NREMS,REMS and TS durations were reduced(P<0. 05). Compared with control group,the EEG waveform characteristics in NG2-Ab group had no significant change. The percentage of δ wave in PCPA group was increased(P<0. 05),while the percentages of α wave and β wave were decreased(P<0. 05). No change of EEG waveform characteristics in 5-HT group was observed. Compared with PCPA group,the percentage of δ wave in NG2-Ab+PCPA group was decreased after administration(P<0. 05). Compared with 5-HT group,the percentage of β wave in NG2-Ab+5-HT group was increased after administration(P<0. 05).CONCLUSION:The NG2 cells in raphe nuclei are involved in the changes of sleep-wake duration and EEG waves caused by the change of 5-HT content.