GABA and muscimol open ion channels of different lifetimes on cultured mouse spinal cord cells.
Intracellular recordings of cultured mouse spinal neurons were used to examine the effects of gamma-aminobutyric acid (GABA) and the GABA analog muscimol on neuronal excitability. Muscimol was about twice as effective as GABA in increasing membrane conductance to C1-ions. Fluctuation analysis of membrane current responses showed that muscimol activated ion channels with the same conductance as GABA but with about the average duration. The results provide an economical explanation for the greater potency of muscimol in depressing excitability.
D000818:Animals; D002478:Cells, Cultured; D004553:Electric Conductivity; D004622:Embryo, Mammalian; D007473:Ion Channels / Q000187:drug effects / Q000378:metabolism*; D007700:Kinetics; D008564:Membrane Potentials / Q000187:drug effects; D051379:Mice; D009118:Muscimol / Q000494:pharmacology*; D009474:Neurons / Q000187:drug effects / Q000502:physiology; D010080:Oxazoles / Q000494:pharmacology*; D013116:Spinal Cord / Q000187:drug effects / Q000502:physiology*; D005680:gamma-Aminobutyric Acid / Q000494:pharmacology*
D007473:Ion Channels; D010080:Oxazoles; D009118:Muscimol; D005680:gamma-Aminobutyric Acid