Sen Madhumita, Gleason Evanna
Department of Biological Sciences, Louisiana State University, Baton Rouge, Louisiana 70803, USA.
Vis Neurosci. 2006 Mar-Apr;23(2):221-31. doi: 10.1017/S0952523806232073.
We have examined the distribution of metabotropic glutamate receptors (mGluRs) 1 and 5 in the adult chicken retina using preembedding immuno-electronmicroscopy. Immunoreactivity for mGluRs 1 and 5 was found in both the outer plexiform layer (OPL) and the inner plexiform layer (IPL). For mGluR1, OPL labeling was observed at cone pedicles and horizontal and bipolar cell processes. In the IPL, mGluR1 labeling could be found on bipolar cell terminals, as well as postsynaptic processes, including amacrine cell processes. Neither presynaptic nor postsynaptic elements were labeled at rod synapses. For mGluR5, OPL labeling was associated with cone pedicles as well as bipolar and horizontal cell processes. As for mGluR1, rod synapses were unlabeled. In the IPL, labeling for mGluR5 was found on bipolar cell terminals and amacrine cell processes. The presynaptic expression of these receptors in the OPL was confirmed at the light level by double-labeling experiments with SV2. The distributions of mGluRs 1 and 5 indicate that they have the potential to regulate function in both synaptic layers. Furthermore, the similar expression patterns for these two receptors indicate that they might be co-expressed and thus have the potential to interact functionally.
我们利用包埋前免疫电子显微镜技术研究了成年鸡视网膜中代谢型谷氨酸受体（mGluRs）1和5的分布情况。在外部神经丛层（OPL）和内部神经丛层（IPL）均发现了mGluRs 1和5的免疫反应性。对于mGluR1，在视锥细胞终足以及水平细胞和双极细胞突起处观察到OPL标记。在IPL中，mGluR1标记可见于双极细胞终末以及包括无长突细胞突起在内的突触后突起上。在杆体突触处，无论是突触前成分还是突触后成分均未被标记。对于mGluR5，OPL标记与视锥细胞终足以及双极细胞和水平细胞突起相关。与mGluR1一样，杆体突触未被标记。在IPL中，mGluR5标记见于双极细胞终末和无长突细胞突起上。通过与SV2进行双重标记实验，在光镜水平证实了这些受体在OPL中的突触前表达。mGluRs 1和5的分布表明它们有可能在两个突触层中调节功能。此外，这两种受体相似的表达模式表明它们可能共表达，因此有可能在功能上相互作用。
