Presynaptic and postsynaptic localization of GABAB receptors in neurons of the rat retina
Presynaptic and postsynaptic localization of GABAB receptors in neurons of the rat retina
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DOI：
10.1046/j.1460-9568.1998.00156.x
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发表时间：
1998-04-01
影响因子：
3.4
通讯作者：
Brandstätter, JH
中科院分区：
文献类型：
--
作者：
Koulen, P;Malitschek, B;Brandstätter, JH
用特异性抗血清将新近克隆的GABAB受体定位于大鼠视网膜。免疫标记主要见于内、外丛状层(IPL、OPL)，内核层和神经节细胞层的大量细胞。GABA(γ-氨基丁酸)和GABA(B)受体的双标记实验表明，GABA(B)受体在水平细胞和无长突细胞中共定位。电子显微镜显示OPL的GABA(B)受体定位于突触前水平细胞突起，内陷到光感受器终末。在IPL中，GABA(B)受体存在于无长突细胞的突触前，也存在于无长突细胞和神经节细胞的突触后。此外，还研究了GABA(B)受体的出生后发育，并在视网膜神经元的形态和突触分化之前观察到免疫反应。目前的结果提示GABA(B)受体在突触前(自身受体)和突触后的作用。此外，突触外GABA(B)受体的定位可能表明GABA在视网膜具有旁分泌功能。
The recently cloned GABAB receptors were localized in rat retina using specific antisera. Immunolabelling was detected in the inner and outer plexiform layers (IPL, OPL), and in a number of cells in the inner nuclear layer and the ganglion cell layer. Double-labelling experiments for GABA (gamma-aminobutyric acid) and GABA(B) receptors, respectively, demonstrated a co-localization in horizontal cells and amacrine cells. Electron microscopy showed that GABA(B) receptors of the OPL were localized presynaptically in horizontal cell processes invaginating into photoreceptor terminals. In the IPL, GABA(B) receprors were present presynaptically in amacrine cells, as well as postsynaptically in amacrine and ganglion cells. The postnatal development of GABA(B) receptors was also studied, and immunoreactivity was observed well before morphological and synaptic differentiation of retinal neurons. The present results suggest a presynaptic (autoreceptor) as well as postsynaptic role for GABA(B) receptors. In addition, the extrasynaptic localization of GABA(B) receptors could indicate a paracrine function of GABA in the retina.