大鼠丘脑前核神经元内γ-氨基丁酸及其受体的表达

目的:探讨大鼠丘脑前核内γ-氨基丁酸(GABA)及其GABAA受体(GABAARα1和β2subunits)的表达,从形态学角度为系统研究丘脑前核的功能提供依据。方法:分别采用包埋后胶体金免疫电镜技术和原位杂交检测丘脑前核内GABA及GABAARα1和β2mRNA的表达。结果:(1)在丘脑前核,GABAARα1和GABAARβ2阳性神经元分布较密集,细胞形态较一致。空白对照切片为阴性,未见GABAARα1和GABAARβ2mRNA表达阳性神经元。(2)GABA胶体金免疫反应切片上,GABA胶体金颗粒浓重标记GrayⅡ型轴突终末,而树突、神经元、胶质细胞及背景标记极少。GABA能阳性轴突终末与中小型树突形成对称性轴-树突触,也与神经元胞体形成对称性轴-体突触。结论:提示在丘脑前核能够合成GABAARα1和GABAARβ2,且GABA能轴突终末与神经元的树突或胞体形成对称性突触。

The expression of GABA and GABA receptors in the anterior thalamus nucleus of rats

Objective:To explore expression of GABA and GABAA receptor subunits (GABAARα1 and β2 subunits) in the anterior thalamic nucleus of rat.Methods:The mRNA of GABAARα1 and β2 subunits were examined by in situ hybridization histochemical staining.GABA was examined with post-embedding immunogold electron microscopic detection method.Results:(1) The mRNA of GABAARα1 and β2 subunits distributed in anterior thalamic nucleus.Control sections were negative for the expression of mRNA of GABAARα1 and β2 subunits.(2) In GABA immunogold reactive sections,Gray tpyeⅡterminals were heavily labeled,and the background labeling was sparse.Dendrits,neuronal and glial cell bodies were very sparse.All GABA positive terminals formed exclusively symmetric synaptic contacts with dendrites and somatas.Conclusion:The mRNA of GABAARα1 and β2 subunits were distributed in anterior thalamic nucleus.GABA positive axon terminals established symmetric synaptic contacts with somatas and dentrites.