title: Single-channel currents from zona-free mouse eggs.
abstract: Cell-attached patch recordings were made from zona-free mouse eggs to examine currents at the single-channel level; two types were identified. A channel with a mean conductance of 130 pS showed changes in reversal potential on dilution of the patch pipette solution consistent with a cation channel; the channel current persisted when the only cation in the pipette was K+: it was concluded that this channel was permeable to K+. The binomial distribution was used to describe the proportion of time 0, 1, 2, ..., n channels were open in multichannel recordings of the K+ channel. Bursts of inward currents of about 1 pA, which showed voltage activation and could be recorded in the presence of CsCl and tetraethylammonium (TEA), were identified as Ca2+ channels.
mesh_terms: D000818:Animals; D002118:Calcium / Q000378:metabolism*; D007473:Ion Channels / Q000502:physiology*; D008564:Membrane Potentials; D051379:Mice; D008807:Mice, Inbred BALB C; D008839:Microelectrodes; D010063:Ovum / Q000502:physiology*; D011188:Potassium / Q000378:metabolism*; D013696:Temperature
chemical_list: D007473:Ion Channels; D011188:Potassium; D002118:Calcium