低频重复经颅磁刺激对慢性应激抑郁模型大鼠行为学及脑内单胺类神经递质的影响

目的观察低频重复经颅磁刺激（rTMS）对慢性应激抑郁模型大鼠行为学及不同脑区内单胺类神经递质含量的影响，探讨低频rTMS对抑郁症的治疗作用及其机制。方法选用12只SD雄性大鼠制备慢性轻度不可预见性应激抑郁模型，造模后随机分为磁刺激组和抑郁模型组，磁刺激组给予低频rTMS治疗，并与正常对照组进行比较。各组大鼠于磁刺激前、后进行敞箱试验、蔗糖水消耗试验，并采用高效液相色谱法检测大鼠不同脑区内单胺类神经递质的含量。结果抑郁模型组大鼠敞箱试验的水平运动得分、垂直运动得分和蔗糖水消耗量与正常对照组比较，差异均有统计学意义（P〈0．01）。磁刺激组大鼠经磁刺激后，敞箱试验的水平运动得分、垂直运动得分和蔗糖水消耗量与磁刺激前比较，均明显增高（P〈0．01）；与抑郁模型组模拟磁刺激后比较，也明显增高（P〈0．01）；与正常对照组比较，差异无统计学意义（P〉0．05）。抑郁模型组大鼠额叶皮质内5-羟色胺、海马内5-羟色胺及多巴胺、纹状体内多巴胺、下丘脑内5．羟色胺含量均明显低于正常对照组和磁刺激组（P〈0．01）；磁刺激组大鼠额叶皮质内5-羟色胺、海马内5-羟色胺及多巴胺、纹状体内多巴胺、下丘脑内5．羟色胺含量与正常对照组比较，差异均无统计学意义（P〉0．05）。结论低频rTMS能明显改变慢性应激抑郁模型大鼠的抑郁行为；对不同脑区内单胺类神经递质水平的调节作用是低频rTMS的抗抑郁机制之一。

Effects of low frequency repetitive transcranial magnetic stimulation on the behavior and cerebral monoamine neurotransmitter in the rats model of chronically depressive stress

Objective To observe the change of behavior and monoamine neurotransmitter in different cerebral areas of the rats model of chronically depressive stress after low frequency repetitive transcranial magnetic stimulation (rTMS), and to study the therapeutic effects and the mechanism of low frequency rTMS on depression. Methods Twelve male Sprague-Dawley rats were exposed to an unpredictable sequence of mild stress to establish the depression model of rats. Rats of depression model were randomly allocated to two groups: a depression model group and a magnetic stimulation group,another 6 normal rats served as the control group. Before and after the repetitive transcranial magnetic stimulation treatment, the rats were evaluated in terms of their behavior with open-field test, the consumption of sucrose solution of rats of three groups and the concentration of monoamine neurotransmitter in diffe-rent cerebral area by HPLC. Results Rats of depression model group showed no significant difference (P>0.05) in level and vertical movements, consumption of sucrose solution when compared with that pre-treatment. Rats of depression model group showed a reduction in level and vertical movements in the open-field test, consumption of sucrose solution with significant difference when compared with those of the control group (P<0.01).Rats of the magnetic stimulation group showed an significant increase in level and vertical movements, consumption of sucrose solution as compared with those of pre-treatment and depression model group (P<0.01). Rats of the magnetic stimulation group showed no significant difference (P>0.05) in level and vertical movements, consumption of sucrose solution when compared with control group. The level of 5-hydroxytryptamine in frontal brain regions, 5-hydroxytryptamine and dopamine in hippocampus,dopamine in corpus striatum, 5-hydroxytryptamine in hypothalamus in the depression model group was lower than that in the control group (P<0.01). The level of 5-hydroxytryptamine in frontal brain regions, 5-hydroxytryptamine and dopamine in hippocampus, dopamine in corpus striatum, 5-hydroxytryptamine in hypothalamus in magnetic stimulation group was higher than that in depression model group (P<0.01). There were no significant difference (P>0.05) in level of 5-hydroxytryptamine and dopamine between magnetic stimulation group and the control group. Conclusion Low frequency rTMS can change the depressive behavior of rats with experimental depression. To regulate the level of monoamine neurotransmitter in different cerebral areas might be one of the antidepressive mechanisms of low frequency rTMS.