Abstract
About 10% of bipolar cells in salamander retina synthesize and take up gamma-aminobutyric acid (GABA), and may use GABA as a neurotransmitter. As GABA uptake is electrogenic, bipolar cells expressing GABA transporters (GATs) should give transport current (IGAT) to extracellular GABA. Using whole-cell patch recording, 28 bipolar cells responded to 30-200 microM GABA puffed to the axon terminals with a picrotoxin (PTX)-sensitive chloride current (ICI) only. Another three bipolar cells had, in addition to ICI, a PTX-resistant, sodium-dependent current that was completely and reversibly blocked by NO-711, an IGAT inhibitor, indicating that this component was an IGAT. This finding provides further support for a subset of GABAergic bipolar cells in the salamander retina.
Publication types
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Research Support, U.S. Gov't, P.H.S.
MeSH terms
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Animals
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Carrier Proteins / analysis
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Carrier Proteins / metabolism*
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GABA Antagonists / pharmacology
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GABA Plasma Membrane Transport Proteins
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Ion Channels / metabolism*
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Membrane Proteins / analysis
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Membrane Proteins / metabolism*
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Membrane Transport Proteins*
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Nipecotic Acids / pharmacology
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Organic Anion Transporters*
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Oximes / pharmacology
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Patch-Clamp Techniques
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Picrotoxin / pharmacology
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Retina / cytology
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Retina / metabolism*
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Sodium / metabolism
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Urodela / metabolism*
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gamma-Aminobutyric Acid / metabolism*
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gamma-Aminobutyric Acid / pharmacology
Substances
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Carrier Proteins
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GABA Antagonists
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GABA Plasma Membrane Transport Proteins
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Ion Channels
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Membrane Proteins
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Membrane Transport Proteins
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Nipecotic Acids
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Organic Anion Transporters
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Oximes
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Picrotoxin
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NNC 711
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gamma-Aminobutyric Acid
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Sodium