A comparison between the distinct inward currents activated in rat cultured dorsal root ganglion neurones by intracellular flash photolysis of two forms of caged cyclic guanosine monophosphate.
Whole cell inward currents activated by intracellular photorelease of cyclic guanosine monophosphate (cGMP) were investigated in cultured dorsal root ganglion (DRG) neurones. The actions of two distinct types of caged cGMP (NPE-caged cGMP and a highly water-soluble caged cGMP) were compared. Rapidly activating inward currents were evoked by cGMP in a subpopulation (12.5%) of neurones and these currents may be due to activity of cyclic nucleotide-gated channels. In contrast in 52% of DRG neurones intracellular photorelease of cGMP activated a delayed Ca(2+)-dependent inward current through the generation of cyclic ADPribose and mobilisation of Ca(2+) from ryanodine sensitive intracellular stores. Similar delayed inward currents were activated by both caged compounds but only NPE-caged cGMP evoked rapidly activating currents. Cyclic GMP appears to increase excitability in some DRG neurones by diverse mechanisms.
Pollock
J
J
Department of Biomedical Sciences, Institute of Medical Sciences, The University of Aberdeen, Foresterhill, AB25 2ZD, Scotland, Aberdeen, UK.
Crawford
J H
JH
Wootton
J F
JF
Corrie
J E T
JE
Scott
R H
RH
D000818:Animals; D000831:Animals, Newborn; D002478:Cells, Cultured; D006152:Cyclic GMP / Q000378:metabolism / Q000528:radiation effects*; D005727:Ganglia, Spinal / Q000166:cytology / Q000502:physiology / Q000528:radiation effects*; D006157:Guanosine Monophosphate / Q000031:analogs & derivatives / Q000378:metabolism / Q000528:radiation effects*; D015640:Ion Channel Gating; D007473:Ion Channels / Q000502:physiology / Q000528:radiation effects*; D009474:Neurons / Q000502:physiology / Q000528:radiation effects*; D018408:Patch-Clamp Techniques; D010782:Photolysis; D051381:Rats; D014466:Ultraviolet Rays
D007473:Ion Channels; C473118:P-1-(2-nitrophenyl)ethyl cGMP; C473119:guanosine 3',5'-cyclic((4-(N,N-bis(carboxymethyl)carbamoyl)-2-nitrophenyl)methyl phosphate); D006157:Guanosine Monophosphate; D006152:Cyclic GMP