海马内微量注射K252a对大鼠行为学及抑郁样经典指标的影响

Changes of behavior and depression-like classic indicators after hippocampal microinjection of K252a

目的海马内微量注射K252a,研究其对大鼠行为学及抑郁样经典指标的影响,拟建立一种新型抑郁症动物模型。方法 SD大鼠随机分为5组,即空白对照组、假手术组、慢性应激抑郁模型组、海马内微量注射K252a组、海马内微量注射K252a联合慢性应激组。采用Open field实验、糖水消耗实验、Morris水迷宫测定大鼠行为学的影响,ELISA法检测大鼠血清单胺递质含量的变化,放射免疫法观察大鼠血浆CRH、ACTH、CORT含量的变化,Western blotting观察大鼠海马BDNF、CREB、ERK1/2、BCL-2蛋白表达的变化。结果与空白对照组比较,CUMS组大鼠的活动量、糖水消耗量、学习记忆能力显著降低(P<0.05或P<0.01),HPA轴功能亢进(P<0.01),血清单胺递质水平降低(P<0.01),BDNF、CREB、ERK1/2、BCL-2的表达下调(P<0.01或P<0.05),而DMSO组上述指标差异无统计学意义;与DMSO比较,K252a组、K252a+CUMS组活动量、糖水消耗量、学习记忆能力显著下降(P<0.01或P<0.05),血清单胺递质水平下降(P<0.01或P<0.05),HPA轴功能显著上升(P<0.01或P<0.05),海马BDNF、CREB、ERK1/2、BCL-2的表达显著下降(P<0.01或P<0.05);与CUMS组比较,K252a组、K252a+CUMS组大鼠上述指标差异无显著性;与K252a组比较,K252a+CUMS组大鼠上述指标差异无显著性。结论从行为学、血液学、分子生物学的不同角度分析表明,此模型与经典的慢性应激抑郁模型在表面效度、结构效度、功能效度上具有极大的相似性,可为病因研究和抗抑郁药物筛选提供一个可供选择的研究技术平台。

Objective To study the changes of behavior and depression-like classic indicators after hippocampal microinjection of K252 a,and to establish a new animal model of depression. Methods SD rats were randomly divided into five groups,namely the control group,sham group,chronic stress depression model group,hippocampal of K252 a microinjection group,and hippocampal microinjection K252 a plus chronic stress group. Open field experiments,sucrose consumption test,and Morris water maze behavioral assay were used to assess the behavioral changes in the rats. ELISA was used to detect the plasma monoamine neurotransmitter,radioimmunoassay was used to determine the plasma CRH,ACTH,CORT contents,and western-blotting was performed to observe the protein expression of BDNF,CREB,ERK1/2,and BCL-2 in the hippocampus. Results Compared with the control group,the amount of activity,sugar consumption,learning and memory abilities were decreased（P〈0. 05 or P〈0. 01）,also the serum monoamine neurotransmitters were decreased（P〈0. 01）,HPA axis function was improved（P〈0. 01）,and the expression of BDNF,CREB,ERK1/2,BCL-2 decreased in the CUMS group（P〈0. 05 or P〈0. 01）,but there was no significant difference in the DMSO group.Compared with the DMSO group,the activity,consumption of sucrose,learning and memory ability were significantly decreased（P〈0. 05 or P〈0. 01）,while the HPA axis function was increased（P〈0. 05 or P〈0. 01）,the serum monoamine neurotransmitters decreased（P〈0. 05 or P〈0. 01）,and the BDNF,CREB,ERK1/2,BCL-2 expressions in the hypocampus were significantly decreased（P〈0. 05 or P〈0. 01） in the K252 a group and K252 a ＋ CUMS group.Compared with the CUMS group,the K252 a group and K252 a ＋ CUMS group did not show significant changes in these parameters. Compared with the K252 a group,these indicators were not significantly changed in the K252 a ＋ CUMS group. Conclusions The results of behavior,hematology,and molecular biology analysis show that this model has a great similarity to the classical model of CUMS in surface validity,construct validity,and functional validity. It may provide an alternative investigative technology platform for basic research and antidepressant drug screening.