Study On The Reward Effect Of Acupuncture Analgesia Mediated By Pyramidal Neurons In The Ventromedial Prefrontal Cortex

Objective:The reward effect of analgesia will drive the motivation and behavior related to pain relief,thus accelerating the pain relief,which has important clinical significance.At the same time,the focus of our study is to change the brain's reward system so as to achieve the goal of pain control and provide research direction for clinical operation.This study from the reward of acupuncture analgesia effect and the prefrontal cortex to participate in the regulation of acupuncture analgesia launches the research work,want to clear the reward of acupuncture analgesia effect,discussed under the rim of the prefrontal cortex area(infralimbic prefrontal cortex,IL)glutamate can pyramidal neurons involved in acupuncture analgesia and the reward,to the innovation of acupuncture analgesia research idea,in order to further clarify the neurobiological mechanisms of acupuncture analgesia to provide new ideas and new perspective.Method : This subject is carried out through three experiments.Experiment 1: acupuncture alleviated incision pain and conditioned position preference(CPP)in rats.Twenty-four adult male SD rats were randomly assigned to the model group,model + non-acupoint group,model + electroacupuncture group,and sham operation + electroacupuncture group to establish a model of incision pain in rats.Electroacupuncture was accompanied by CPP training and testing,and the residence time of rats in the preference box and non-preference box was observed.Experiment 2: to observe the effect of acupuncture on the expression of IL FOS protein in the lower margin of the ventromedial prefrontal cortex(CPP)after the test of analgesic CPP in the surgical incision pain rat model.Twenty adult male SD rats were randomly assigned to the model group,model + non-acupoint group,model + electroacupuncture group,sham operation group + electroacupuncture group,and sham operation group.The experimental process was the same as Experiment 1.On the last day,brain samples were taken out and IL brain areas were conducted immunofluorescence histochemistry.Experiment 3: Use acupuncture analgesia CPP to test the edge of the medial prefrontal cortex of rat's abdomen glutamate pyramidal neurons discharge.Twenty adult male SD rats were randomly assigned to the model group,model + non-acupoint group,model + electroacupuncture group,sham operation group + electroacupuncture group,and sham operation group.Multi-channel microarray electrophysiological technique was used to elucidate the role of prefrontal cortex neuron discharge in acupuncture analgesic reward.Fifteen adult male SD rats were randomly assigned to the model group,model + electroacupuncture group and sham operation + electroacupuncture group.The rats implanted with electrodes underwent daily intervention and training.The experiment process was the same as Experiment 1.Then I recorded the firing of neurons in the brain,and collected the signals from neurons for analysis.Results: 1)There was a significant difference between the groups(F=463.887,P<0.001).Compared with each groups,the model group showed significantly shorter thermal-sensitive pain shrinking paw score,and electroacupuncture of zusanli,shenshu and sanyinjiao in rats with postoperative incision pain could significantly reduce the incision pain of rats(P<0.001).Conditional position preference score(F=26.784,P<0.001)was found to be significantly higher in the control group than in the model group,and Zusanli,Shenshu,and Sanyinjiao could all significantly induce rewarding effect in rats(P<0.001).2)Immunofluorescence results showed that there were significant differences between the groups(F=29.793,P<0.001),and the number of c-fos in the rats with surgical incision pain after acupuncture was significantly increased compared with other groups(P<0.001).3)There was a significant difference in the ratio between the number of electrophysiological spick emission on the side of the preference box and the number of electrophysiological spick emission on the side of the preference box(F=16.455,P<0.001).The analgesic effect of acupuncture on the incision pain model rats was more active than that of other groups(P<0.001).Conclusion:(1)Electroacupuncture alleviated incision pain in rats and induced conditioned position preference in rats.(2)Acupuncture analgesic reward effect can activate glutamate neurons in the ventromedial prefrontal cortex.