Regulation of Dopamine Release from Interplexiform Cell Processes in the Outer Plexiform Layer of the Carp Retina |
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Authors: | Patricia M O'Connor Charles L Zucker John E Dowling |
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Institution: | Department of Cellular and Developmental Biology, Harvard University, Cambridge, Massachusetts, U.S.A. |
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Abstract: | The gamma-aminobutyric acid (GABA) antagonists bicuculline and picrotoxin stimulate a four- to fivefold increase in endogenous dopamine release from isolated intact carp retina. The release evoked by these agents is Ca2+ dependent, a finding suggesting a vesicular release. Using light microscopic autoradiography, we have localized the sites of dopamine release to the dopaminergic interplexiform cell processes of the outer plexiform layer, which synapse onto horizontal cells. Our findings support previous suggestions that the dopaminergic interplexiform cells receive GABAergic inhibitory input and that the effects of GABA antagonists on horizontal cells are mediated by dopamine release from the interplexiform cells. |
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Keywords: | γ-Aminobutyric acid antagonists Dopamine release Interplexiform cell Autoradiography Horizontal cell |
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