Tetraethylammonium (TEA) ions blocked the unitary currents through the delayed rectifier potassium channels of Drosophila neurons from the cytoplasmic side of inside-out membrane patches by two distinct mechanisms. Fist, TEA attenuated the single-channel conductance, probably by producing very rapid block-unblock reactions at the inner mouth of the potassium pore. Second, TEA markedly enhanced the slow inactivation, making the incidence of channel openings highly nonrandom; blank traces with no channel openings during repetitive depolarizations showed a significant tendency to be clustered in the presence of TEA. This second action accounts for almost half of the reduction of average current produced by 10 mM internal TEA.
|Journal||American Journal of Physiology - Cell Physiology|
|Publication status||Published - 1989 Jan 1|
ASJC Scopus subject areas
- Cell Biology