Hippocampal knock down of NMDA receptor induces deficit of PPI

本实验符合北里大学关于实验动物伦理使用的指导方针。选用雄性Wistar大鼠。采用大鼠双侧海马区单次注射NR1反义-HVJ-脂质体复合体的方法进行NR1海马区基因敲除。Western印迹分析证实NR1反义核酸可持续下调NR1的表达。Western印迹分析表明，NR1反义治疗特异性地下调了NR1在海马区的表达(约30%)，持续了一周以上。首先，在反义诱导的NMDA受体NR1亚单位(NR1)敲除大鼠的海马区，产生了脉冲前抑制(PPI)的破坏。接下来，我们检查了多巴胺受体拮抗剂氟哌啶醇(HPD)是否能恢复NR1基因敲除大鼠PPI的这种中断，以阐明谷氨酸功能障碍与多巴胺功能亢进之间的关系。在PPI试验中，应用中、高剂量的HPD可促进反义NR1基因敲除大鼠PPI缺陷的恢复。

The present experiment conformed to the Guidelines on the ethical use of laboratory animals of Kitasato University. Male Wistar rats were used. The NR1 hippocampal knockdown was performed by single injection of NR1 antisense-HVJ-liposome complex into the bilateral hippocampus of rats. The sustained downregulation of expression of NR1 by NR1-antisense was confirmed by western blot analysis. Western blot analysis demonstrated that the NR1-antisense treatment provided specifically the downregulation (about 30%) of NR1 expression in the hippocampus for more than a week. Firstly, it was shown that disruption of pre-pulse inhibition (PPI) was produced in the rats with antisense-induced hippocampal knockdown of NMDA receptor NR1 subunit (NR1). Next, we examined whether this disruption of PPI in NR1 knockdown rats was recovered by dopamine receptor antagonist haloperidol (HPD), to clarify the relation between glutamate dysfunction and dopamine hyperfunction. On the PPI test, application of moderate or high dose of HPD induced recovery from defective PPI in the rats with NR1 knockdown by antisense.