Activation of single potassium channels in rat cerebellar granule cells by volatile anesthetics.

1. We recently reported that volatile anesthetics activate a potassium channel (S channel) in neurons of the marine mollusk, Aplysia (Winegar et al., 1996. Anesthesiology 85(4) 889-900). 2. These studies were extended to investigate volatile anesthetic actions on potassium channels in rat cerebellar granule cells. 3. Noninactivating potassium channels were observed across a wide range of potentials. 4. Channel activity increased during volatile anesthetic perfusion while the i-V relations were unchanged and remained weakly inward-rectifying with a conductance at negative potentials of approximately 30 pS. 5. Frequent opening of inward rectifiers by volatile anesthetics may stabilize the resting potential near E(K) to resist depolarizing stimuli.