Identification of M-channels in outside-out patches excised from sympathetic ganglion cells.
We have identified the species of K+ channel that underlies the neuronal M-current in rat sympathetic ganglion cells. The channels were kinetically and pharmacologically defined using outside-out and cell-attached patches. They exhibited multiple conductance levels, predominantly 3-9 pS. Their slow gating in response to voltage change in outside-out patches was exhibited only in the presence of AIF-4 or GTP gamma S on the inner membrane surface and when the lower conductance states were dominant. In the absence of AIF-4 or GTP gamma S, the channels exhibited rapid activation and deactivation. We conclude that M-channel gating may be controlled by an associated GTP-binding protein.
Stansfeld
C E
CE
Department of Pharmacology, University College London, England.
Marsh
S J
SJ
Gibb
A J
AJ
Brown
D A
DA
D000535:Aluminum / Q000494:pharmacology; D017607:Aluminum Compounds; D000818:Animals; D001464:Barium / Q000494:pharmacology; D004553:Electric Conductivity; D004594:Electrophysiology; D005459:Fluorides; D005461:Fluorine / Q000494:pharmacology; D005728:Ganglia, Sympathetic / Q000166:cytology / Q000378:metabolism*; D016244:Guanosine 5'-O-(3-Thiotriphosphate) / Q000494:pharmacology; D015640:Ion Channel Gating; D007473:Ion Channels / Q000187:drug effects / Q000502:physiology*; D007700:Kinetics; D011930:Reaction Time
D017607:Aluminum Compounds; D007473:Ion Channels; C050992:tetrafluoroaluminate; D001464:Barium; D005461:Fluorine; D016244:Guanosine 5'-O-(3-Thiotriphosphate); D000535:Aluminum; D005459:Fluorides