Effects of Electroacupuncture on Hippocampal AcH3 and BDNF in the Rat Model of SNI-induced Pain-Depression Dyad / 中山大学学报(医学科学版)

ABSTRACT

ObjectiveTo observe the impacts of electroacupuncture （EA） on the expression of hippocampal brain-derived neurotrophic factor （BDNF） and acetylated histone （AcH3） in the rat model of spared nerve injury （SNI）， so as to explore the analgesic and antidepressant effects of EA. MethodsTwenty-four Male SD rats were randomly divided into 4 groups， with 6 in each group. SNI was used to establish the model of pain and depression. All the groups were intervened one week after SNI surgery and persisted 5 weeks. The EA group was treated with EA （2 Hz） for 30 min every other day and imipramine drug group （IMP） group with peritoneal imipramine injection （10 mg/kg） per day. The sham surgery group （SS） and model group （SNI） received the same grasping stimulation. The paw mechanical withdrawal threshold （PWT） test was performed before the SNI surgery， 1， 2， 3， 4， 5， and 6 weeks after surgery， respectively. The forced swimming test （FST） and the sucrose preference test （SPT） were performed 6 weeks after SNI surgery. The Western blot method was employed to detect the expression of BDNF and AcH3 from the rat hippocampal tissue at the end of the behavioral tests. ResultsCompared with the SS group， the SNI group had significantly decreased PWT and sucrose consumption， prolonged FST immobility time （all P<0.01）， down-regulated BDNF and AcH3 expression （P<0.05 & P<0.01） in the hippocampus， which indicated the successful construction of the pain-depression model. Compared with the SNI group， 6 weeks after SNI surgery， the EA and IMP groups had significantly increased PWT and sucrose consumption， and reduced FST immobility time （all P<0.01）； the EA group had up-regulated BDNF and AcH3 expression （both P<0.05） in the hippocampus， the IMP group had up-regulated AcH3 （P<0.05） expression but no difference in BDNF expression. ConclusionEA could relieve pain and depressive behavioral symptoms in SNI rats. And its analgesic and antidepressant mechanisms may relate to the up-regulation of hippocampal AcH3 and BDNF expression.