title: Synaptic pattern of nicotinic acetylcholine receptor α7 and β2 subunits on the direction-selective retinal ganglion cells in the postnatal mouse retina.
abstract: Direction-selective retinal ganglion cells (DS RGCs) respond strongly to a stimulus that moves in their preferred direction, but respond weakly or do not respond to a stimulus that moves in the opposite or null direction. DS RGCs are sensitive to acetylcholine, and starburst amacrine cells (SACs) make cholinergic synapses on DS RGCs. We studied the distributions of nicotinic acetylcholine receptor (nAChR) α7 and β2 subunits on the dendritic arbors of DS RGCs to search for anisotropies that contribute to the directional preferences of DS RGCs. The DS RGCs from the retinas of postnatal mice (postnatal day P5, P10, and P15) were injected with Lucifer yellow, and injected cells were identified by their dendritic morphology. The dendrites of the DS RGCs were labeled with antibodies for either the nAChR α7 or β2 subunit as well as postsynaptic density protein-95 (PSD-95), visualized by confocal microscopy, and reconstructed from high-resolution confocal images. The distribution of nAChR subunits on the dendritic arbors in both the ON and OFF layers of the RGCs revealed an asymmetrical pattern on early postnatal day P5. However, the distributions of nAChR subunits on the dendritic arbors were not asymmetric on P10 and P15. Our results therefore provide anatomical and developmental evidence suggesting that the nAChR α7 and β2 subunits may involve in the early direction-selectivity formation of DS RGCs in the mouse retina.
authors.affiliation: Department of Biology, School of Life Sciences, KNU Creative BioResearch Group (BK21 Plus Program), College of Natural Sciences, and Brain Science and Engineering Institute, Kyungpook National University, Daegu 702-701, South Korea; Department of Life Sciences, Pohang University of Science and Technology, Pohang, Kyungpook 790-784, South Korea.
authors.forename: Hyun Jin
authors.initials: HJ
authors.lastname: Kim
authors.affiliation: Department of Biology, School of Life Sciences, KNU Creative BioResearch Group (BK21 Plus Program), College of Natural Sciences, and Brain Science and Engineering Institute, Kyungpook National University, Daegu 702-701, South Korea. Electronic address: cjjeon@knu.ac.kr.
authors.forename: Chang Jin
authors.initials: CJ
authors.lastname: Jeon
mesh_terms: D000818:Animals; D000831:Animals, Newborn; D003712:Dendrites / Q000378:metabolism*; D005456:Fluorescent Dyes; D007546:Isoquinolines; D051379:Mice; D008810:Mice, Inbred C57BL; D018613:Microscopy, Confocal; D008856:Microscopy, Fluorescence; D011978:Receptors, Nicotinic / Q000378:metabolism*; D012160:Retina / Q000378:metabolism*; D012165:Retinal Ganglion Cells / Q000378:metabolism*; D013569:Synapses / Q000502:physiology; D009435:Synaptic Transmission / Q000502:physiology*; D064569:alpha7 Nicotinic Acetylcholine Receptor / Q000378:metabolism*
chemical_list: D005456:Fluorescent Dyes; D007546:Isoquinolines; D011978:Receptors, Nicotinic; D064569:alpha7 Nicotinic Acetylcholine Receptor; C579166:Chrna7 protein, mouse; C017475:lucifer yellow
keywords: direction-selectivity; immunocytochemistry; living cell injection; nicotinic acetylcholine receptor; retinal ganglion cell; starburst amacrine cells