慢性不可预见性温和刺激抑郁症模型大鼠的脑PET成像研究

A PET study on brain of chronic unpredictable mild stimulations( CUMS)-induced depressive rats

目的通过PET成像技术研究慢性不可预见性温和刺激(CUMS)致抑郁症大鼠的全脑代谢特点。方法实验组大鼠给予CUMS 4周后,通过糖水偏嗜度、自发活动距离、体质量等指标分为刺激后抑郁大鼠(D组)及刺激后非抑郁大鼠(ND组),并与正常对照组大鼠(CON组)一起行PET检查,比较不同组大鼠之间全脑的代谢变化。结果 (1)D组大鼠的双侧S1、丘脑、苍白球、岛叶、M2、左屏状核较CON组代谢升高,右侧下丘、胼胝体压部、小脑则代谢降低;(2)D组大鼠双侧海马CA3区、M1、M2、纹状体、S1、嗅球等区较ND组代谢增高,左侧楔状核及海马则代谢降低;(3)ND组大鼠与CON组相比,无代谢升高的脑区,而外侧隔核、双侧纹状体、下丘脑室旁核、双侧S1、右侧苍白球则代谢降低。结论以前囟后4 mm处为界,抑郁大鼠脑代谢特点是前高后低,左右大致对称。抑郁症的发生可能与多个脑区功能的异常相互作用有关。

Objective To observe the metabolic changes in the whole brain of chronic unpredictable mild stimulations（ CUMS）-induced depressive rats using PET imaging technology. Methods After 4 weeks＇ of CUMS,rats of experimental group were divided into two groups： Group D（ depression） and Group ND（ no depression）,according to the degree of sugar addiction,distance of spontaneous activity and relative body mass. Then metabolic changes in the whole brain of these rats and those in control group（ CON） were observed using PET technology,and the differences were companred between the three groups. Results（ 1） Compared with Group CON,metabolism of Group D was elevated in bilateral S1,thalamus,globus pallidus,insula,M2 and left claustrum,but descended in right inferior colliculus,splenium of corpus callosum and cerebellum.（ 2） Metabolism of Group D increased in the bilateral CA3 region of hippocampus,M1,M2,striatum,S1 and olfactory bulb,but decreased in the left cuneate nucleus and hippocampus compared to Group ND.（ 3） Compared with Group CON,there was no region of the brain in Group ND where metabolism was enhanced,but metabolism in the lateral septal nucleus,bilateral striatum,hypothalamic paraventricular nucleus,bilateral S1 and right globus pallidus of Group ND was reduced. Conclusion The metabolic characteristic in the brain of depressive rats is that heightened regions are all in front of the coronal plane 4 mm post bregma,while lowered regions are behind. Moreover,both cerebral hemispheres are roughly symmetrical. It can be concluded that abnormal interactions between different regions of the brain contributes to the occurrence of depression.