THE EFFECTS OF BUSPIRON ON STRUCTURAL PLASTICITY OF SYNAPSES AND CaMKII OF HIPPOCAMPAL AND AMYGDALAR SYNAPSES IN MORPHINE WITHDRAWAL RATS

Objective:To explore the cellular and molecular mechanism of buspirone on anxiety in morphine withdrawal rats.Methods:The 66 male SD rats were randomly divided into three groups: the saline(control),the morphine(model),and the buspirone(treatment).Gradually increasing dosage of morphine with hypodermic injection is applied to validate the morphine dependence for 10 days before the elevated plus maze.Thus,the model rats are subjected to buspirone treatment for 1-3 d.The tissue of hippocampal region of CA3 and amygdala was harvested to test the scores of Nv(numerical density),Sv(surface density) and S(surface) with electron microscopy stereology.Total and phosphorylated levels of CaMKⅡ are detected by Western blotting.Results:Compared with the model group,the rats treated with buspirone had higher frequency and longer time in open arm(P0.01 or P0.05),and the lower values of Nv and Sv and higher score of S were observed in CA3 region of hippocampus and amygdale(P0.01 or P0.05).However,the decreased parameters of contents and the phosphorylase levels of CaMKⅡ were observed in the treated group(P0.01 or P0.05).Conclusion:Reversion of synaptic structural plasticity of hippocampus and amygdale and changed expression levels of CaMKⅡ may attribute the anxiolytic effects of buspirone in morphine withdrawal rats.