Continuous Effects Of Chiropractic On Endocannabinoid Receptors And Related Hydrolases In The Hippocampus Of A Rat Model Of Autism

ObjectiveTo explore the persistent effects of chiropractic on endocannabinoid receptors and related hydrolases in the hippocampus of autism model rats.MethodsIn this experiment,20 pairs of SPF grade Wistar rats of reproductive age,male and female 1:1overnight,early in the next morning,the female mice were recorded as embryonic day 0.5(embryofoday,E0.5),the male and female mice were raised in separate cages,and the pregnant mice were randomly divided into blank and VPA groups.At 12.5 days of pregnancy,both pregnant mice were given intraperitoneally with 0.24 m L/100 g by intraperitoneal injection,VPA group received 250mg/m L sodium valproate solution(Sodium valproate,VPA),and blank group was injected with equal volume normal saline intraperitoneally;the offspring were identified as autism model mice after testing and screening by developmental behavior(development,orientation experiment,forced swimming experiment,hot plate pain experiment).In this experiment,56 eligible autistic model mice were selected,which were divided into 7 groups according to random number table: model group,chiropractic group,group 1d after intervention,group 2d after intervention,group 4d after intervention,group 8d after intervention and group 16 d after intervention;and 8 normal rats were selected as blank group.Empty group and model group did not intervene,simulated capture for 28 days,the remaining 6groups for chiropractic intervention,once a day,21 times each time,after 28 days of continuous intervention,immediately,1d,2d,4d,8d,16 d materials.Eight groups of rats were tested before intervention and sampling,the brain hippocampus tissue was obtained by immunohistochemistry to detect endogenous cannabinoid CB1/CB2 receptor expression in the hippocampus,and western blot analysis(Western Blot)was used to detect the expression of endocanna-binoid CB1/CB2 receptor and related metabolic enzyme FAA H/M AGL protein.Results1.Body weight index: Weight index: Compared with the blank group,the VPA group had less weight in PN7,PN7),PN14 and PN21,with significant differences(P<0.001).2.Eye opening experiment: compared with the mice in the blank group,the eye opening scores in the VPA group were not significantly different in PN12,PN13 and PN14(P>0.05),and the eye open scores in PN15 and PN16 were significantly lower,with significant differences(P<0.001).3.Forced swimming experiment: Compared with the mice in the blank group,the swimming ability of the VPA group was significantly lower in PN9,PN11 and PN13,with significant difference(P<0.001),and no significant difference between the two groups at PN15(P>0.05).4.Directional taxis experiment: compared with the mice in the blank group,the mice in the VPA group were different in PN7,PN8,PN9 and PN10(P<0.05).5.Hot board induced pain experiment: compared with the mice in the blank group,the mice in the VPA group had significantly dull pain perception,with significant differences in PN9,PN11,PN13 and PN15(P<0.001).6.Open field behavior: 1)Before intervention: compared with the blank group,the total activity distance and central area activity distance,the proportion of central area activity distance to total distance(Rd),the decrease of standing times and the increase of waging times were significantly different(P<0.05).There was no statistical difference between groups except blank(P>0.05).2)After intervention: Compared with the model group,the model group,chiropractic group,1d after intervention,2d after intervention,4d after intervention(P<0.05).7.Western blot: 1)Compared with the blank group,the model group had increased FAAH,MAGL protein expression,and decreased CB1 R protein expression in the hippocampus(P<0.05),and no significant difference in CB2 R protein expression(P>0.05).2)Compared with the model group,the expression of FAAH and MAGL decreased in the 4d group,while the expression of CB1 R increased significantly(P<0.05),the expression of FAAH and MAGL decreased,the expression of CB1 R,and CB2 R increased significantly(P<0.05),and there was no significant difference between other groups compared with the model group(P>0.05).8.Immunohistochemistry: 1)Compared with the blank group,the CB1 R protein expression was significantly reduced in the model group(P<0.05),and there was no significant difference in CB2 R protein expression(P>0.05).2)Compared with the model group,the CB1 R protein expression increased in 4d and 8d after kneading(P<0.05),with no significant difference among other groups(P>0.05);there was no significant difference in CB2 R protein expression between the spinal and 5 groups compared with the model group(P>0.05).Conclusions1.VPA autistic rats have reduced spontaneous activity,repetitive rigid symptoms,exploration and anxiety disorder ASD like symptoms.2.One course of chiropractic intervention with 28 d can improve the spontaneous activity of VPA autistic rats,alleviate stereotyped movements,improve exploration desire,and reduce the generation of anxiety-like behavior,and this treatment effect peaked at the 4-8d after the end of chiropractic,then began to weaken,but still continued until the 16 d after the end of chiropractic.3.The sustained effect of chiropractic therapy is most likely achieved by the up-regulation of the endocannabinoid system by CB1 R protein expression and downregulation of FAAH and MAGL proteins in VPA autistic rats.