Retinotectal transmission in the optic tectum of rainbow trout
Retinotectal transmission in the optic tectum of rainbow trout
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DOI：
10.1002/cne.20473
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发表时间：
2005-04-04
影响因子：
2.5
通讯作者：
Ito, E
中科院分区：
文献类型：
--
作者：
Kinoshita, M;Fukaya, M;Ito, E
视顶盖细胞水平上的视网膜顶盖传递还没有得到很好的描述。为了解决这个问题，我们使用了硬骨鱼，彩虹鲑鱼，并将脑室周围神经元描述为突触后细胞，预计将接受视顶盖的视网膜顶盖输入。室周神经元的胞体位于脑室周层(SPV)的上部，而SPV的下部是放射状胶质细胞的胞体层。钙离子成像在脑室周围神经元发现了功能性的离子型谷氨酸受体。我们还克隆了N-甲基-D-天冬氨酸(N-甲基-D-天冬氨酸)受体NR1亚单位和(+/-)-alpha-amino-3-hydroxy-5-methyl-isoxazole-4-propionic酸(AMPA)受体GluR2亚基的编码基因，并用原位杂交的方法检测了它们在脑室周围神经元中的表达。免疫印迹和免疫组织化学方法也证实了脑室周围神经元树突中存在受体亚单位蛋白。另一方面，SPV下部的放射状胶质细胞对谷氨酸没有反应，在胶质细胞中未检测到离子型谷氨酸受体的mRNA和免疫反应。这些结果表明，视网膜顶盖传入神经元和脑室周围神经元之间的突触谷氨酸能传递是由功能性的NMDA和AMPA受体介导的。(C)2005年Wiley-Liss，Inc.
Retinotectal transmission has not yet been well characterized at the cellular level in the optic tectum. To address this issue, we used a teleost, the rainbow trout, and characterized periventricular neurons as postsynaptic cells expected to receive the retinotectal inputs to the optic tectum. The somata of periventricular neurons are localized in the upper zone of the stratum periventriculare (SPV), whereas the lower zone of the SPV comprises the cell body layer of radial glial cells. Ca2+ imaging identified functional ionotropic glutamate receptors in periventricular neurons. We also cloned cDNAs encoding the NR1 subunit of N-methyl-D-aspartic acid (NMDA) receptors and the GluR2 subunit of (+/-)-alpha-amino-3-hydroxy-5-methyl-isoxazole-4-propionic acid (AMPA) receptors, and detected their mRNAs in periventricular neurons by in situ hybridization. The presence of the receptor subunit proteins was also confirmed in the dendrites of periventricular neurons by immunoblotting and immunohistochemistry. On the other hand, radial glial cells in the lower zone of the SPV did not respond to glutamate applications, and mRNA and immunoreactivities of ionotropic glutamate receptors were not detected in glial cells. The present findings suggest that glutamatergic transmission at synapses between retinotectal afferents and periventricular neurons is mediated by the functional NMDA and AMPA receptors. (C) 2005 Wiley-Liss, Inc.