Influence of Acupuncture and Medication on Hippocampus ɑ_1-AR mRNA in a Rat Model of Depression

Objective To investigate the role of the central norepinephrine system in the pathogenesis and treatment of depression. Methods A rat model of depression was made by chronic stress induction. The expression of ɑ1 receptor mRNA in the hippocampus was examined by an in situ hybridization technique. Results (1) The number of ɑ1-AR mRNA expression-positive neurons increased in the hippocampus in the rat models of depression and was significantly larger in CA3 and DG regions compared with the control group (P0.01),while the average optical density of the expression-positive neurons decreased and was significantly lower in DG region compared with the control group (P0.05). (2) In the early stage (3 days),the number of ɑ1-AR mRNA expression-positive neurons decreased in the fluoxetine group and was significantly lower especially in DG region compared with the combined acupuncture and medicine group (P0.05). (3) In the middle and late stages (7~14 days),the average optical density of ɑ1-AR mRNA expression-positive neurons tended to increase and was significantly higher in CA1 region especially at 14 days in the fluoxetine group than in the combined acupuncture and medicine group (P0.05). (4) In most of the periods,a positive expression of ɑ1 receptor mRNA in the acupuncture group was similar to that in the combined acupuncture and medicine group. Conclusion ɑ1-AR activity decreases in single hippocampal neuron in depression rats. Single or combined use of acupuncture and fluoxetine can influence the expression of ɑ1 receptor mRNA in the hippocampus,but each has its characteristic effect and there is a difference in time effect between the two.