大鼠展神经核向动眼神经核的兴奋性和抑制性投射研究

Study on excitory and inhibitory projections from abducens to oculomotor nucleus in rats

目的:研究展神经核向动眼神经核内直肌亚核投射的神经递质通路。方法:利用荧光金(fluoro-gold,FG)逆行追踪结合免疫荧光组织化学双标技术观察大鼠展神经核内FG逆行标记细胞和谷氨酸(glutamate,Glu)、γ-氨基丁酸(γ-amino-butyric acid,GABA)、谷氨酸受体1型(glutamate Receptor 1,GluR1)、谷氨酸脱羧酶(glutamicacid decarboxylase,GAD)免疫阳性神经元的分布。结果:注射FG于大鼠动眼神经核内直肌亚核后,在对侧展神经核内可见FG逆行标记细胞,为展神经核的核间神经元。其中,谷氨酸及其受体1型免疫标记阳性的分别占70.41%和53.70%,而GABA和GAD免疫反应阳性神经元则分别占投射神经元的11.31%和8.27%。结论:在展神经核向对侧动眼神经核内直肌亚核投射的核间通路中,主要以谷氨酸为兴奋性神经递质,而GABA可能不是起主要的抑制性神经递质。

Objective：To study neurotransmitter pathway from abducens to medial rectus subdivision of oculomotor nucleus in rats.Methods：FG（fluoro-gold）retrogradely labeling combined with imunofluorescent double labeling technique were used to observe the distribution of FG retrolabeling cells and glutamate（GLu）,Glutamate Receptor 1（GluR1）,γ-amino-butyric acid（GABA）,γ-amino-butyric acid（GABA） and glutamic acid decarboxylase（GAD） immunopositive neurons in abducens in rats.Results：After injection of FG into medial recteus subnucleus of oculomotor neurons,FG retrolabeling cells were found in the contralateral abducens internuclear neurons.70.41% and 53.70% of these retrolabeling cells were Glu and GluR1 positive cells respectively,while GABA and GAD positive cells account for 11.31% and 8.27% retrolabeling cells respectively.Conclusions：Glu is the main excitory neurotransmitter,while GABA is not the main inhibitory neurotransmitter in the internuclear pathway from abducens nucleus to medial recteus subnucleus of oculomotor neurons.