Effect of Electroacupuncture on Chronic Visceral Pain and Involvement of Spinal NMDA Receptor in IBS Rats

Objective:To clarify effect of electroacupuncture (EA) on relieving chronic visceral pain and the underlying neurobiological mechanism for such an effect,we observed the effect of EA on the Irritable bowel syndrome (IBS) rat and then examined spinal expression of N-methyl-D-aspartate (NMDA)receptor-1 in rats.Methods:Daily mechanical colon distention was performed on male Sprague-Dawley neonatal rats to produce IBS model.EA was applied at acupoints of Zusanli (ST 36) and Shangjuxu (ST 37)in each hind leg.Abdominal withdrawal reflex (AWR) assessment or rectus abdominis electromyograms (AEMG) recordings were then performed after EA treatment.The mRNA expression of the NMDA subtype of glutamate receptors in the spinal dorsal horn (L4-5) before and after EA was investigated by RT-PCR analysis in IBS rats.Results:The results demonstrated that EA could significantly decreased both AWR scores from behavioral test and AEMG discharges from electrophysiological recording in IBS model rats elicited by colorectal distension (CRD) stimuli with strengths of 20,40,60 and 80 mmHg,respectively (P＜0.05).Meanwhile there was a significant decrease in mRNA expression of NMDA receptor-1 in the spinal dorsal horn of IBS rats treated by EA (P＜0.05),but no such effect was observed in IBS rats treated by sham EA (inserting needles without electrical stimulation).Conclusion:These results indicate that EA can relieve chronic visceral hyperalgesia in IBS rats and this effect might be correlated with the down-regulation of NMDA receptor-1 in the dorsal hom of the spinal cord.

罗建红教授团队在《细胞研究》发文阐明N－甲基－D－门冬氨酸受体含GluN2 A亚型选择性调控的新机制

近日，浙江大学医学院罗建红教授团队在《细胞研究》（ Cell Research）发表了研究论文“Activity－induced synaptic delivery of the GluN2A－containing NMDA receptor is dependent on endoplasmic reticulum chaperone Bip and involved in fear memory”（http：／／www．nature．com／cr／journal v／25／n7fullcr201575a．html）。该研究首次发现内质网分子伴侣蛋白Bip介导了N－甲基－D－门冬氨酸（ NMDA）受体含GluN2A亚型选择性的突触表达，从而调控中枢神经系统的可塑性和动物行为。

Objective:　To investigate the relationship between the changes of N-methyl-D-aspartate (NMDA) receptor activity and brain edema after injury in rats.　　Methods:　The brain injury models were made by using a free-falling body. The treatment model was induced by means of injecting AP5 into lateral ventricle before brain injury; water contents in brain cortex were measured with dry-wet method; and NMDA receptor activity was detected with a radio ligand binding assay.　　Results:　The water contents began to increase at 30 minutes and reached the peak at 6 hours after brain injury. The maximal binding (Bmax) of NMDA receptor increased significantly at 15 minutes and reached the peak at 30 minutes, then decreased gradually and had the lowest value 6 hours after brain injury. Followed the treatment with AP5, NMDA receptor activity in the injured brain showed a normal value; and the water contents were lower than that of AP5-free injury group 24 hours after brain injury.　　Conclusions:　It suggests that excessive activation of NMDA receptor may be one of the most important factors to induce the secondary cerebral impairments, and AP5 may protect the brain from edema after brain injury.