猫丘系层Glu与GABA表达的年龄相关性变化

为探讨青年猫和老年猫丘系层谷氨酸（Glu）与γ-氨基丁酸（GABA）表达的年龄相关性变化,利用Nissl染色显示丘系层神经元,免疫组织化学ABC法标记Glu和GABA免疫阳性神经元。光镜下观察、拍照,对Glu和GABA能免疫阳性神经元分别计数并换算成密度。利用IPE软件测量Glu和GABA免疫阳性反应灰度值（免疫阳性强度与灰度值成反比）。结果显示,Glu和GABA阳性反应神经元、阳性纤维及其终末在青年猫及老年猫丘系层均有分布。与青年猫相比,老年猫丘系层Glu能免疫阳性神经元密度显著增大（p〈0.01）,免疫阳性反应灰度值显著降低（p〈0.01）,免疫阳性反应显著增强;GABA能免疫阳性神经元密度显著下降（p〈0.01）,免疫阳性反应灰度值显著升高（p〈0.01）,免疫阳性反应显著减弱。结果提示,衰老过程中猫丘系层Glu的表达增强和GABA的表达减弱导致兴奋性神经递质和抑制性神经递质之间的平衡失调,可能是视觉、听觉、躯体感觉等单感觉功能衰退及多感觉整合功能增强的主要原因之一。

Age-related changes of Glu and GABA expression in the stratum lemnisci of cat

To investigate the age-related changes of Glu/GABA expression in the stratum lemnisci of the young and old cats,Nissl staining was used to display all the stratum lemnisci neurons and the immunohistochemical method was introduced to exhibit the Gluergic and GABAergic neurons.Under the microscope,the number of Gluergic and GABAergic neurons were counted and their gray values were counted respectively with Image-pro Express Software 5.1.The Glu and GABA immunoreactive cells,the fibers and their terminals were distributed widely in the stratum lemnisci of both young and old cats.Compared with young cats,the density of Gluergic neurons ascended significantly in old cats（p0.01）and its gray value was significantly lower（p0.01）,immunoreactivity markedly increased;GABAergic neurons density decreased significantly（p0.01）,gray value had increased clearly（p0.01）,immunoreactivity had dropped evidently.An evident loss of GABAergic neurons and the increasing of Gluergic neurons in the stratum lemnisci of old cats may result in an imbalance of excitement and inhibition,which might be one of important reasons for visual,auditory,somatosensory single sensory function degeneration and multisensory integration enhanced.