Differential developmental expression of the two rat brain glutamate transporter proteins GLAST and GLT
Differential developmental expression of the two rat brain glutamate transporter proteins GLAST and GLT
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DOI：
10.1111/j.1460-9568.1997.tb01522.x
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发表时间：
1997-08-01
影响因子：
3.4
通讯作者：
Danbolt, NC
中科院分区：
文献类型：
--
作者：
Ullensvang, K;Lehre, KP;Danbolt, NC
兴奋性神经递质谷氨酸的细胞外浓度通过神经元和神经胶质细胞的质膜中的谷氨酸转运体的作用而保持较低。这些转运体可能不仅在成人脑中，而且在发育中的脑中发挥重要作用，因为谷氨酸被认为调节突触的形成和消除以及神经元迁移、增殖和凋亡。在这里，我们证明了两个谷氨酸转运蛋白，GLAST和GLT，通过定量免疫印迹和光镜和电镜免疫细胞化学的表达的发展变化。在出生时，GLT是检测不到的，但GLAST是目前在前脑和小脑中的显着浓度。GLT首先分别在第二周和第三周在前脑和小脑中检测到。这两种转运蛋白在出生后第5周达到成人水平。在前脑中的总谷氨酸摄取活性的发展，确定在脂质体中的转运蛋白的溶解和重建，平行的GLT，与GLT是在成人大脑中的主要转运蛋白的观察。幼年和成年大鼠组织中GLAST和GLT的区域分布相似。电镜观察表明，GLAST和GLT仅存在于幼年和成年动物的胶质细胞中。
The extracellular concentration of the excitatory neurotransmitter glutamate is kept low by the action of glutamate transporters in the plasma membranes of both neurons and glial cells, These transporters may play important roles, not only in the adult brain, but also in the developing brain, as glutamate is thought to modulate the formation and elimination of synapses as well as neuronal migration, proliferation and apoptosis. Here we demonstrate the developmental changes in the expression of two glutamate transporters, GLAST and GLT, by quantitative immunoblotting and by light and electron microscopic immunocytochemistry. At birth, GLT is not detectable, but GLAST is present at significant concentrations both in the forebrain and in the cerebellum. GLT is first detected in the forebrain and cerebellum in the second and third week, respectively. Both transporters reach adult levels by postnatal week 5. The development of the total glutamate uptake activity in the forebrain, as determined by solubilization and reconstitution of the transporters in liposomes, parallels that of GLT, in agreement with the observation that GLT is the predominant transporter in the adult brain. The regional distributions of both GLAST and GLT in the tissue are similar in young and adult rats. Only GLAST is detectable in the external germinal layer of the cerebellar cortex, Electron microscopical investigation demonstrated GLAST and GLT exclusively in glial cells in young as well as in adult animals.