小鼠脊髓神经元内脑啡肽与1型囊泡膜谷氨酸转运体的共存

目的:以PPE-GFP转基因小鼠为研究工具,观察绿色荧光蛋白(GFP)阳性的脑啡肽(ENK)能神经元与1型囊泡膜谷氨酸转运体(VGLUT1)在脊髓的分布及共存情况。方法:利用免疫组织化学和原位杂交双标染色的方法。结果:GFP标记的ENK能神经元主要位于脊髓背角,在I-ⅡI层最为密集,背角深层内侧部及中央管周围呈中等密度分布,散在分布于前角。VGLUT1 mRNA阳性细胞广泛分布在脊髓各层。GFP/VGLUT1双标细胞主要分布在脊髓背角,I-ⅡI层双标细胞占GFP阳性细胞的22.95±1.10%,占VGLUT1阳性细胞的27.91±2.42%;IV-VI层中21.49±4.99%GFP阳性细胞表达VGLUT1,10.35±2.81%VGLUT1阳性细胞表达GFP;前角双标细胞占VGLUT1阳性细胞的1.07±0.37%,占GFP阳性细胞的32.08±13.15%。结论:双标结果表明脊髓内部分ENK能神经元表达1型囊泡膜谷氨酸转运体,推测ENK能神经元可能通过调控谷氨酸的释放发挥感觉信息调控作用。

Co-localization of enkephalin and vesicular glutamate transporter 1 in the neurons of mouse spinal cord

Objective: To investigate the coexistence of enkephalin(ENK)ergic neuron with vesicular glutamate transport 1(VGLUT1) in the spinal cord of the PPE-GFP transgenic mouse.Methods: Immunohistochemistry and in situ hybridization double staining methods.Results: GFP-positive cells were preferentially localized in the spinal dorsal horn and were particularly numerous in laminae I-ⅡI.The moderate density GFP-and scattered GFP-positive cells were also detected in the media part of deep lemina and aroun the central tube,and the ventral horn,respectively.VGLUT1 mRNA signals were present throughout the spinal cord.The GFP/VGLUT1 double-labeled neurons were mainly located in spinal dorsal horn.We found that 22.95±1.10% of GFP-positive ENKergic neurons expressed VGLUT1 and 27.91±2.42% of VGLUT1-positive neurons expressed ENK in the laminae I-ⅡI.The GFP/VGLUT1 double-labeled neurons constituted 21.49±4.99% and 32.08±13.15% of GFP-positive neurons in laminae VI-VI and the ventral horn,respectively.The GFP/VGLUT1 double-labeled neurons constituted 10.35±2.81% and 1.07±0.37% of VGLUT1-positive neurons in laminae VI-VI and the ventral horn,respectively.Conclusion: The present results showed that part of the spinal ENKergic neurons expressed VGLUT1.These results indicate that ENKergic neurons might be involved in the modulation of sensory information by regulating the release of glutamic acid.