Experiment Study Of Relationship Of P2X4Receptor In Spinal Dorsal Horn And Central Pain After Spinal Cord Injury

Objectives:(1) L1spinal cord injury SD rats model of central pain are established bythe method of Allen’sWADE.(2)Observe the morphological changes of microglia andexpression of P2X4receptor by immunohistochemical staining, and preliminary studythe role of the P2X4receptor in the mechanism of central pain after spinal cord injury.Methods: L1spinal cord injury SD rats model are established by the method ofAllen’s WADE. All rats are randomly divided into normal control group, sham group,spinal cord injury group (SCI group): observed pontaneous pain after surgery everyday.0day,1day,3days,7days,14days,21days,28days after surgery, detect pawmechanical withdrawal threshold (PMWT) and paw withdrawal thermal latency(PWTL)to all rats. By appearance of the central pain, the rats in SCI group arere-divided into the no central pain group (NCP group) and central pain group (CPGroup)after spinal cord injury.These are ready for the next experiment.(2)observepositive expression of the P2X4receptor by immunohistochemistry.Results:(1) L1spinal cord injury rat model were established successfully bymethod of Allen’sWADE:SD rats appeared typical paralysis of the double lower limbsafter spinal cord injury; given zero mark to performance of rats by the standardof”BBB” in24hours after spinal cord injury, and the pathology showed histologicalfeatures of spinal cord injury.These showed that the rat model of L1spinal cord injurywere established successfully;(2)Rats model of central pain after spinal cord injurywere established successfully:3days after spinal cord injury, eight rats showedautophagy in SCI group. These rats showed scratching, licking, even self-mutilation,grooming behavior to the body below the level of injury. All rats in normal controlgroup,sham group and the other12rats in SCI group did not appear autophagyphenomenon.At same time, found that the12rats(Including8rats in theabove-mentioned) in SCI group, PWMT and PWTL showed decreasing notablely.(3) P2X4receptor expression in Spinal dorsal horn: The normal group showed neverpositive expression, Sham group and NCP group showed little positve expression, CPgroup showed more positive expression than any other group.The CP group were morethan the NCP group (P <0.05),and were also more than in positive expression in spinaldorsal horn to the normal group and sham group (P <0.01).NCP group were more thanin positive expression in spinal dorsal horn to the normal group and sham group (P<0.05), Normal control group and sham group showed no significant difference(P<0.05).Conclusions:(1)Rat model of central pain after spinal cord injury are established well by themethod of Allen’s WADE, Signs and symptoms of the model rats are similar to the CPpatient.(2) P2X4receptor in the spinal dorsal horn may play important role in centralpain after spinal cord injury.