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Presynaptic and postsynaptic localization of GABA B receptors in neurons of the rat retina
Author(s) -
Koulen Peter,
Malitschek Barbara,
Kuhn Rainer,
Bettler Bernhard,
Wässle Heinz,
Brandstätter Johann Helmut
Publication year - 1998
Publication title -
european journal of neuroscience
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.346
H-Index - 206
eISSN - 1460-9568
pISSN - 0953-816X
DOI - 10.1046/j.1460-9568.1998.00156.x
Subject(s) - postsynaptic potential , neuroscience , retina , gabaa receptor , receptor , chemistry , biology , biochemistry
The recently cloned GABA B receptors were localized in rat retina using specific antisera. Immunolabelling was detected in the inner and outer plexiform layers (IPL, OPL), and in a number of cells in the inner nuclear layer and the ganglion cell layer. Double‐labelling experiments for GABA (γ‐aminobutyric acid) and GABA B receptors, respectively, demonstrated a co‐localization in horizontal cells and amacrine cells. Electron microscopy showed that GABA B receptors of the OPL were localized presynaptically in horizontal cell processes invaginating into photoreceptor terminals. In the IPL, GABA B receptors were present presynaptically in amacrine cells, as well as postsynaptically in amacrine and ganglion cells. The postnatal development of GABA B receptors was also studied, and immunoreactivity was observed well before morphological and synaptic differentiation of retinal neurons. The present results suggest a presynaptic (autoreceptor) as well as postsynaptic role for GABA B receptors. In addition, the extrasynaptic localization of GABA B receptors could indicate a paracrine function of GABA in the retina.