丘脑束旁核-纹状体神经元轴突终末的超微结构证实  

The ultrastructure evidence for PFn-striatal axonal terminals in rats

作　　者：刘冰冰[1] 欧阳丽斯[1] 穆淑花[1] 朱亚西[1] 李可一[1] 雷万龙[1] 

机构地区：[1]中山大学中山医学院人体解剖学教研室,广东广州510080

出　　处：《解剖学研究》2009年第5期325-329,共5页Anatomy Research

基　　金：国家自然科学基金(30570572;30770679)

摘　　要：目的研究丘脑束旁核(PFn)-纹状体神经元轴突终末的分布和超微结构特征,以及与纹状体神经元之间的形态学联系。方法借助于神经示踪剂BDA10K注射方法顺行标记PFn神经元,光镜和电镜下观察和计数阳性纤维在纹状体内的数量和分布形式以及超微结构特征,实验资料借助于SPSS软件统计处理分析和体视学观察。结果①PFn神经元轴突终末在纹状体内呈散在不均匀分布;背侧区显著多于腹侧区(P<0.001),而外侧区与内侧区之间差异无统计学意义(P=0.387)。②光镜高倍镜观察显示大量的BDA阳性纤维与纹状体不同类型神经元(包括NeuN阳性、Darpp-32阳性以及Parv阳性神经元)的胞体和突起在形态学上存在明显的相邻关系。③电镜观察和测量结果显示BDA阳性终末平均直径为(0.648±0.288)μm,同时发现它们与纹状体神经元之间主要形成兴奋性(非对称型)突触连接;阳性轴突终末的65.18%与树突形成兴奋性突触,其直径为(0.651±0.304)μm;剩余的34.82%[平均直径为(0.642±0.257)μm]与树突棘形成兴奋性突触连接。结论丘脑PFn-纹状体神经元轴突终末主要分布于纹状体的背侧区,并与纹状体不同类型的神经元显示相邻关系,电镜超微结构下证实其突触形式主要为轴-树兴奋性突触连接,结果提示丘脑PFn神经元对纹状体不同类型的神经元的影响可能具有选择性和特异性。Objective The study purposes to confirm the distribution and ultrastructure of striatal axonal terminals in rats, as well as the morphologie relationship with striatum neurons. Method We injected the tracer BDA10K into the thalamo-parafaseieular nucleus in SD rats to label their axonal terminals anterogradely, and then counted and observed distribution and uhrastructure of positive axonal terminals in striatum at light microscopy and electron microscopy level. The experimental data were analyzed with SPSS. Results The distribution of BDA＋ terminals in rat striatum was heterogeneous, and the positive terminals in the dorsal striatum were more than the ventral striatum （P〈0.001）, while the number of them had no difference between the lateral striatum and medial striatum（P=0.387）. ②At high-power light microscopy level, many BDA＋ terminals were adjacent to the soma and processes of striatal different neurons （including NeuN＋ neuron, Darpp-32＋ neuron and Parv＋ interneuron）. ③The electron microscopy data showed that the size of BDA＋ terminals was （0.648±0.288） μm and the majority of them synapsed with striatum projection neurons, and 65.18% of them [their size, （0.651±0.304）μm] formed excitability synapses with the dendrites of striatum neurons, while 34.82% [（0.642±0.257）μm in mean diameter] with spines. Conclusion The BDA＋ terminals of thalamus preferentially projected to the dorsal striatum, and connected with the different striatum neuron types. The uhrastructures of electron microscopy revealed that the BDA＋ terminals mainly formed the axo-dendritic excitatory synapse with striatum neurons. The results indicated that the effects of PFn-striatal neurons on striatal different neuron types had selectivity and specificity.

关 键 词：丘脑PFn 纹状体 NeuN神经元 Darpp-32神经元 Parv神经元 

分 类 号：R741[医药卫生—神经病学与精神病学]