ABSTRACT
Objective To evaluate the changes in the expression of neuroligin1 in excitatory postsynaptic membrane of the spinal dorsal horn in a rat model of inc isional pain.Methods Forty-eight pathogen-free healthy adult male Sprague-Dawley rats,aged 6-8 weeks,weighing 280-320 g,were divided into control group (group C,n =12) and incisional pain group (group Ⅰ,n=36) using a random number table.A1 cm long incision was made in the plantar surface of the right hindpaw in group Ⅰ.Cumulative pain score (CPS) was assessed and mechanical paw withdrawal threshold to von Frey stimuli was measured at 3 hand 1 and 3 days after operation (T1,2,3).The animals were then sacrificed and their lumbar segments (L3-6) of the spinal cord were removed for detection of the expression of neuroligin1,postsynaptic density-95 protein (PSD-95),glutamate receptor 1 (GluR1) and GluR2 in the postsynaptic membrane of spinal dorsal horn (by Western blot) and co-expression of neuroligin1 with PSD-95 in spinal dorsal horn (by co-immuno-precipitation).Results Compared with group C,CPS was significantly increased and mechanical paw withdrawal threshold was decreased at T1-3,and the expression of neuroligin1 and GluR1 in the postsynaptic membrane of spinal dorsal horn at T1,2 and co-expression of neuroligin1 with PSD-95 at T1 were up-regulated in group Ⅰ (P＜0.01 or 0.05).Conclusion The development and maintenance of incisional pain is related to the signaling pathway regulated by neuroligin1 in excitatory postsynaptic membrane of the spinal dorsal horn of rats.