Abstract
We have identified a putative cGMP-gated cation conductance in rat retinal ganglion cells. Both in situ hybridization and polymerase chain reaction amplification detected transcripts in ganglion cells that were highly homologous to the cGMP-gated cation channel expressed in rod photoreceptors. Whole-cell patch-clamp recordings detected a current stimulated by cGMP due to activation of nonselective cation channels. This current had a reversal potential near 0 mV, showed some outward rectification, and could be blocked by Cd2+. The current could also be activated by a phosphodiesterase inhibitor and the nitric oxide donors sodium nitroprusside and S-nitrosocysteine. We propose that nitric oxide released from an identified subpopulation of amacrine cells may activate this channel to modulate ganglion cell activity.
Publication types
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Research Support, Non-U.S. Gov't
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Research Support, U.S. Gov't, P.H.S.
MeSH terms
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1-Methyl-3-isobutylxanthine / pharmacology
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8-Bromo Cyclic Adenosine Monophosphate / pharmacology
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Animals
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Animals, Newborn
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Base Sequence
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Cells, Cultured
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Cyclic GMP / pharmacology*
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Cyclic Nucleotide-Gated Cation Channels
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Cysteine / analogs & derivatives*
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Cysteine / pharmacology
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DNA Primers
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Electric Conductivity
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Gene Expression*
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In Situ Hybridization
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Ion Channels / biosynthesis
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Ion Channels / drug effects
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Ion Channels / physiology*
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Membrane Potentials / drug effects
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Membrane Potentials / physiology
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Models, Neurological
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Molecular Sequence Data
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Nitric Oxide / pharmacology*
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Nitroprusside / pharmacology*
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Polymerase Chain Reaction
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Rats
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Rats, Wistar
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Retinal Ganglion Cells / drug effects
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Retinal Ganglion Cells / metabolism
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Retinal Ganglion Cells / physiology*
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Retinal Rod Photoreceptor Cells / metabolism
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S-Nitrosothiols*
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Transcription, Genetic
Substances
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Cyclic Nucleotide-Gated Cation Channels
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DNA Primers
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Ion Channels
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S-Nitrosothiols
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Nitroprusside
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8-Bromo Cyclic Adenosine Monophosphate
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Nitric Oxide
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S-nitrosocysteine
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Cyclic GMP
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Cysteine
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1-Methyl-3-isobutylxanthine