Hyperpolarizing shift of the M-current activation curve after washout of muscarine in bullfrog sympathetic neurons.
The mechanism underlying the over-recovery of an M-type potassium current following the washout of muscarine (20 microM) has been examined. Whole-cell recordings were made from single neurons dissociated from bullfrog sympathetic ganglia. During over-recovery, the maximum M-conductance decreased by about 2.8 nS while the steady-state M-current activation curve was displaced in the hyperpolarizing direction by about 13 mV. These data suggest that a hyperpolarizing shift in the kinetics of M-current causes over-recovery in amphibian autonomic neurons.
Tokimasa
T
T
Department of Physiology, Kurume University School of Medicine, Japan. tokimasa@is.icc.u-tokai.ac.jp
Simmons
M A
MA
Schneider
C R
CR
Akasu
T
T
D000818:Animals; D005728:Ganglia, Sympathetic / Q000187:drug effects*; D008564:Membrane Potentials / Q000502:physiology*; D009116:Muscarine / Q000494:pharmacology*; D018408:Patch-Clamp Techniques; D015221:Potassium Channels / Q000187:drug effects*; D011892:Rana catesbeiana; D013997:Time Factors
D015221:Potassium Channels; D009116:Muscarine