Research On The Mechanism Of Acupuncture Upon The Spontaneous Activity Rhythm In Insomnia Rats Based On α7-nAChRs In TRN

Objective:Selecting PCPA insomnia rats as the subjects,this study observed the changes of circadian rhythm cycle of spontaneous activities,synaptic plasticity-related proteins(PSD-95)and α7 nicotinic acetylcholine receptors(α7 n ACh Rs)in PV neurons in TRN region of rats after acupuncture,and discussed the effects of acupuncture on circadian rhythm cycle of spontaneous activities of rats with insomnia and possible central mechanism of acupuncture for insomnia,to provide scientific basis for the application of acupuncture for insomnia.Method:SD rats were placed in the automatic monitoring isolation unit of the rhythm laboratory.After 7 days of domestication with the normal light-dark cycle(L:D=12:12,with lights on at 07:00,and off at 19:00),24 rats whose circadian rhythm cycle of spontaneous activities was synchronized with environmental light-dark cycle were selected,and then randomized into 16 for model replication group and 8 for blank group.Rats in the model replication group were injected intraperitoneally with PCPA suspension(100 g/1ml)at ZT4(11:00),and those in the blank group were given an equal amount of saline(100g/1ml)at ZT4 for 3 consecutive days.After the modulation phase,the rats in the model replication group were randomized into 8 for the model group and 8 for the model + acupuncture group(hereinafter referred to as the model-needle group).ZT4 was selected to bind fixed rats of the mold needle group which were subjected to injection intervention for 5 days,15 minutes for each time,and twisted the needles at the 1st,6th and 11 th minutes.The model and blank groups were bound in the same manner at ZT4 for 15 minutes,for 5 consecutive days without other interventions.The circadian rhythm cycle of spontaneous activities was analyzed by Clocklab and Matlab,and the co-expression of PV,PSD-95,PV and α7 n ACh Rs was detected in immunofluorescence assay.Results:1.During the domestication stage,there was no significant difference in the circadian rhythm cycle of spontaneous activities in all rats(P> 0.05),the periocycles were approximately 24 h.During the modeling stage,compared with the blank group,the circadian rhythm cycle of spontaneous activities in the rats of the model and model-needle groups had the significant difference(P<0.01),those in the rats of the model and model-needle groups had no significant difference(P>0.05).During the acupuncture stage,compared with the model group,the circadian rhythm cycle of spontaneous activities was significantly different in the blank and mold-needle groups(P<0.01),but no significant difference in the blank and mold-needle groups(P>0.05).2.The immunofluorescence double labeling results of PV and PSD-95 showed that the coexpression of PV and PSD-95 in TRN region of brain tissues in the rats of the model group decreased,which was statistically significant to those in the rats of the mold-needle and blank group(P<0.05),but no significant difference between those in the rats of the moldneedle and blank groups(P>0.05).The immunofluorescence double labeling results of PV and α7 n ACh Rs showed that the co-expression of PV and α7 n ACh Rs in TRN region in the rats of the model group decreased,which was statistically significant to those in the rats of the mold-needle and blank groups(P<0.05 or P<0.01),but no significant difference in the mold-needle and blank groups(P>0.05).Conclusions:1.Acupuncture could improve the sleep of rats with insomnia and promote their circadian rhythm cycle of spontaneous activities to resynchronize with the external light-dark cycle.2.α7 n ACh Rs may be involved in acupuncture regulating the synaptic plasticity in PV neurons in the TRN area and circadian rhythm cycle of spontaneous activities in insomnia rats,and the improvement of synaptic plasticity of PV neurons in TRN may be related to the recovery of circadian rhythm cycle of spontaneous activities.