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Different types of ganglion cell share a synaptic pattern
Author(s) -
Xu Ying,
Vasudeva Viren,
Vardi Noga,
Sterling Peter,
Freed Michael A.
Publication year - 2008
Publication title -
journal of comparative neurology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.855
H-Index - 209
eISSN - 1096-9861
pISSN - 0021-9967
DOI - 10.1002/cne.21644
Subject(s) - biology , retina , ganglion , ribbon synapse , excitatory postsynaptic potential , biophysics , confocal microscopy , neuroscience , cell type , confocal , anatomy , membrane , microbiology and biotechnology , synaptic vesicle , cell , inhibitory postsynaptic potential , biochemistry , optics , physics , vesicle
Retinal ganglion cells comprise about 10 morphological types that also differ functionally. To determine whether functional differences might arise partially from differences in excitatory input, we quantified the distributions of ribbon contacts to four mammalian ganglion cell types [brisk‐transient (BT), brisk‐sustained (BS), local edge (LE), directionally selective (DS)], comparing small vs. large and “sluggish” vs. “brisk.” Cells in guinea pig retina were filled with fluorescent dye, immunostained for synaptic ribbons, and reconstructed with their ribbon contacts by confocal microscopy. False‐positive contacts were corrected by performing the same analysis on processes that lack synapses: glial stalks and rod bipolar axons. All types shared a domed distribution of membrane that was well fit by a Gaussian function (R 2 = 0.96 ± 0.01); they also shared a constant density of contacts on the dendritic membrane, both across each arbor and across cell types (19 ± 1 contacts/100 μm 2 membrane). However, the distributions of membrane across the retina differed markedly in width (BT > DS ≈ BS > LE) and peak density (BS > DS > LE > BT). Correspondingly, types differed in peak density of contacts (BS > DS ≈ LE > BT) and total number (BS ≈ BT > DS > LE). These differences between cell types in spatial extent and local concentration of membrane and synapses help to explain certain functional differences. J. Comp. Neurol. 507:1871–1878, 2008. © 2008 Wiley‐Liss, Inc.