Localization of the presynaptic cytomatrix protein Piccolo at ribbon and conventional synapses in the rat retina: Comparison with Bassoon
Tóm tắt
In recent years significant progress has been made in the elucidation of the molecular assembly of the postsynaptic density at synapses, whereas little is known as yet about the components of the presynaptic active zone. Piccolo and Bassoon, two structurally related presynaptic cytomatrix proteins, are highly concentrated at the active zones of both excitatory and inhibitory synapses in rat brain. In this study we used immunocytochemistry to examine the cellular and ultrastructural localization of Piccolo at synapses in the rat retina and compared it with that of Bassoon. Both proteins showed strong punctate immunofluorescence in the outer and the inner plexiform layers of the retina. They were found presynaptically at glutamatergic ribbon synapses and at conventional GABAergic and glycinergic synapses. Although the two proteins were coexpressed at all photoreceptor ribbon synapses and at some conventional amacrine cell synapses, at bipolar cell ribbon synapses only Piccolo was present. Our data demonstrate similarities but also differences in the molecular composition of the presynaptic apparatuses of the synapses in the retina, differences that may account for the functional differences observed between the ribbon and the conventional amacrine cell synapses and between the photoreceptor and the bipolar cell ribbon synapses in the retina. J. Comp. Neurol. 439:224–234, 2001. © 2001 Wiley‐Liss, Inc.
Từ khóa
Tài liệu tham khảo
Cases‐Langhoff C, 1996, Piccolo, a novel 420 kDa protein associated with the presynaptic cytomatrix, Eur J Cell Biol, 69, 214
Gundelfinger ED, 2000, Molecular organization of excitatory chemical synapses in the mammalian brain, Naturwissenschaften, 87, 513, 10.1007/s001140050770
Kidd M, 1962, Electron microscopy of the inner plexiform layer of the retina in the cat and the pigeon, J Anat, 96, 179
Mandell JW, 1992, Differential expression of synapsin I and II among rat retinal synapses, J Neurosci, 12, 1736, 10.1523/JNEUROSCI.12-05-01736.1992
Missotten L, 1965, The ultrastructure of the retina
Raviola E, 1976, Intracellular junctions in the outer plexiform layer of the retina, Invest Ophthalmol, 15, 881
Rieke F, 1996, Asynchronous transmitter release: control of exocytosis and endocytosis at the salamander rod synapse, J Physiol (London), 493, 1, 10.1113/jphysiol.1996.sp021360
Wässle H, 1998, Glycine and GABA receptors in the mammalian retina, Vis Res, 10, 1411, 10.1016/S0042-6989(97)00300-3