摘要
目的观察代谢型谷氨酸受体5(mGluR5)在老年小鼠及Fmr1基因敲除(FMR1-KO)小鼠海马CA1区轴棘突触的配布变化。方法选用3月龄(对照组)、22月龄(老年组)雄性C57BL/6小鼠以及3月龄雄性C57BL/6种系的Fm r1敲-除小鼠各3只。经心灌注固定、震动切片,以银加强纳金包埋前免疫电镜技术对mGluR5在海马CA1区腔隙分子层轴棘突触的突触后分布进行分析。结果 mGluR5标记颗粒主要分布于轴棘突触突触后树突棘质膜内面,突触后致密斑上未见mGluR5标记物的存在。对照组小鼠海马CA1区腔隙分子层轴棘突触mGluR5有29.87%的标记颗粒位于距突触后致密斑边缘60nm的区域内;老年组小鼠有27.02%的标记颗粒位于距突触后致密斑边缘60nm的区域内,与正常组小鼠比较无显著差异;而FMR1-KO小鼠有20.01%的标记颗粒位于距突触后致密斑边缘60nm的区域内,与正常组小鼠比较具有显著差异(P<0.01)。结论衰老未改变海马CA1区轴棘突触mGluR5的配布,Fmr1基因敲除则引起海马CA1区轴棘突触mGluR5配布的改变。
Objective To study the altered distribution of metabotropic glutamate receptor5（mGluR5） in the axospinous synapses of hippocampal CA1 in aged mice and in Fmr1-knockout mice.Methods 3-month-old,22-month-old male C57BL/6 mice and 3-month-old Fmr1-knockout mice in a C57BL/6 background were used.All of mice were transcardially perfused with a fixative.Brains were sectioned using Vibratome.mGluR5 in the axospinous synapses of hippocampal CA1 was labeled and analyzed by pre-embedding silver-intensified immunogold technique at electron microscopic level.Results The marker of mGluR5 by the pre-embedding silver-intensified immunogold method was a non-diffusible and dense particle.The particles were located on the intracellular surface of the plasma membrane of dendritic spine at axospinous synapses.No particles can be observed on postsynaptic density.29.87% and 27.02% immunoparticles were located within 60 nm from the edge of the postsynaptic density respectively in control and aged mice.There was no significant difference between them,while 20.01% can be detected in FMR1-KO mice.Conclusions Aging can not change the distribution of mGluR5 at axospinous synapses,while Fmr1 gene knockout alters mGluR5 distribution at axospinous synapses of hippocampal CA1.
出处
《中国老年学杂志》
CAS
CSCD
北大核心
2010年第24期3684-3686,共3页
Chinese Journal of Gerontology
基金
国家自然科学青年基金(30700437)
河北省自然科学基金(C2006000818)
