Retinal ganglion cells express a cGMP-gated cation conductance activatable by nitric oxide donors.
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.
Ahmad
I
I
Department of Ophthalmology and Visual Science, Yale University School of Medicine, New Haven, Connecticut 06510.
Leinders-Zufall
T
T
Kocsis
J D
JD
Shepherd
G M
GM
Zufall
F
F
Barnstable
C J
CJ
D015056:1-Methyl-3-isobutylxanthine / Q000494:pharmacology; D015124:8-Bromo Cyclic Adenosine Monophosphate / Q000494:pharmacology; D000818:Animals; D000831:Animals, Newborn; D001483:Base Sequence; D002478:Cells, Cultured; D006152:Cyclic GMP / Q000494:pharmacology*; D054815:Cyclic Nucleotide-Gated Cation Channels; D003545:Cysteine / Q000031:analogs & derivatives* / Q000494:pharmacology; D017931:DNA Primers; D004553:Electric Conductivity; D015870:Gene Expression; D017403:In Situ Hybridization; D007473:Ion Channels / Q000096:biosynthesis / Q000187:drug effects / Q000502:physiology*; D008564:Membrane Potentials / Q000187:drug effects / Q000502:physiology; D008959:Models, Neurological; D008969:Molecular Sequence Data; D009569:Nitric Oxide / Q000494:pharmacology*; D009599:Nitroprusside / Q000494:pharmacology*; D016133:Polymerase Chain Reaction; D051381:Rats; D017208:Rats, Wistar; D012165:Retinal Ganglion Cells / Q000187:drug effects / Q000378:metabolism / Q000502:physiology*; D017948:Retinal Rod Photoreceptor Cells / Q000378:metabolism; D026403:S-Nitrosothiols; D014158:Transcription, Genetic
D054815:Cyclic Nucleotide-Gated Cation Channels; D017931:DNA Primers; D007473:Ion Channels; D026403:S-Nitrosothiols; D009599:Nitroprusside; D015124:8-Bromo Cyclic Adenosine Monophosphate; D009569:Nitric Oxide; C021315:S-nitrosocysteine; D006152:Cyclic GMP; D003545:Cysteine; D015056:1-Methyl-3-isobutylxanthine