Glutamate is a major neurotransmitter in the retina and other parts of the central nervous system, exerting its influence through ionotropic and metabotropic receptors. One ionotropic receptor, the N-methyl-D-aspartate (NMDA) receptor, is central to neural shaping, but also plays a major role during neuronal development and in disease processes. We studied the distribution pattern of different subunits of the NMDA receptor within the rat retina including quantifying the pattern of labelling for all the NR1 splice variants, the NR2A and NR2B subunits. The labelling pattern for the subunits was confined predominantly in the outer two-thirds of the inner plexiform layer. We also wanted to probe NMDA receptor function using an organic cation, agmatine (AGB); a marker for cation channel activity. Although there was an NMDA concentration-dependent increase in AGB labelling of amacrine cells and ganglion cells, we found no evidence of functional NMDA receptors on horizontal cells in the peripheral rabbit retina, nor in the visual streak where the type A horizontal cell was identified by GABA labelling. Basal AGB labelling within depolarizing bipolar cells was also noted. This basal bipolar cell AGB labelling was not modulated by NMDA and was completely abolished by the use of L-2-amino-4-phosphono-butyric acid, which is known to hyperpolarize retinal depolarizing bipolar cells. AGB is therefore not only useful as a probe of ligand-gated drive, but can also identify neurons that have constitutively open cationic channels. In combination, the NMDA receptor subunit distribution pattern and the AGB gating experiments strongly suggests that this ionotropic glutamate receptor is functional in the cone-driven pathway of the inner retina.
机构:
Tokyo Med & Dent Univ, Med Res Inst, Lab Mol Neurosci, Bunkyo Ku, Tokyo 1138510, Japan
China Med Univ, Coll Basic Med, Shenyang 110001, Peoples R ChinaTokyo Med & Dent Univ, Med Res Inst, Lab Mol Neurosci, Bunkyo Ku, Tokyo 1138510, Japan
Bai, Ning
Aida, Tomomi
论文数: 0引用数: 0
h-index: 0
机构:
Tokyo Med & Dent Univ, Med Res Inst, Lab Mol Neurosci, Bunkyo Ku, Tokyo 1138510, JapanTokyo Med & Dent Univ, Med Res Inst, Lab Mol Neurosci, Bunkyo Ku, Tokyo 1138510, Japan
Aida, Tomomi
Yanagisawa, Michiko
论文数: 0引用数: 0
h-index: 0
机构:
Tokyo Med & Dent Univ, Med Res Inst, Lab Mol Neurosci, Bunkyo Ku, Tokyo 1138510, JapanTokyo Med & Dent Univ, Med Res Inst, Lab Mol Neurosci, Bunkyo Ku, Tokyo 1138510, Japan
Yanagisawa, Michiko
Katou, Sayaka
论文数: 0引用数: 0
h-index: 0
机构:
Tokyo Med & Dent Univ, Med Res Inst, Lab Mol Neurosci, Bunkyo Ku, Tokyo 1138510, JapanTokyo Med & Dent Univ, Med Res Inst, Lab Mol Neurosci, Bunkyo Ku, Tokyo 1138510, Japan
Katou, Sayaka
Sakimura, Kenji
论文数: 0引用数: 0
h-index: 0
机构:
Niigata Univ, Brain Res Inst, Dept Cellular Neurobiol, Niigata 9518585, JapanTokyo Med & Dent Univ, Med Res Inst, Lab Mol Neurosci, Bunkyo Ku, Tokyo 1138510, Japan
Sakimura, Kenji
Mishina, Masayoshi
论文数: 0引用数: 0
h-index: 0
机构:
Ritsumeikan Univ, Res Org Sci & Technol, Brain Sci Lab, Shiga 5258577, JapanTokyo Med & Dent Univ, Med Res Inst, Lab Mol Neurosci, Bunkyo Ku, Tokyo 1138510, Japan
Mishina, Masayoshi
Tanaka, Kohichi
论文数: 0引用数: 0
h-index: 0
机构:
Tokyo Med & Dent Univ, Med Res Inst, Lab Mol Neurosci, Bunkyo Ku, Tokyo 1138510, Japan
Tokyo Med & Dent Univ, Ctr Brain Integrat Res, Tokyo 1138510, Japan
JST, CREST, Saitama, JapanTokyo Med & Dent Univ, Med Res Inst, Lab Mol Neurosci, Bunkyo Ku, Tokyo 1138510, Japan