Honda E, Teeter J H, Restrepo D
Department of Physiology, Kyushu Dental College, Kitakyushu, Japan.
Brain Res. 1995 Dec 12;703(1-2):79-85. doi: 10.1016/0006-8993(95)01072-6.
InsP3-gated channels present in isolated rat olfactory cilia membranes were studied by recording current fluctuations in cilia membranes fused onto phospholipid bilayers formed at the tip of a patch pipette. We found that InsP3 (1.25 to 30 microM) induced current fluctuations in 18 of 157 otherwise silent bilayers. The ion channels opened by InsP3 could be classified into two groups that differed in terms of conductance and kinetics. One channel, which had a conductance of 37 pS, displayed two current levels, and the larger single channel currents were associated with longer open dwell times. The other channel displayed a larger conductance (103-184 pS). Both types of channels displayed reversal potentials near zero millivolts, consistent with nonspecific cation channels. These experiments suggest that mammalian olfactory neurons possess two types of ciliary InsP3-gated channels.
通过记录融合到膜片吸管尖端形成的磷脂双分子层上的纤毛膜中的电流波动，研究了分离的大鼠嗅觉纤毛膜中存在的肌醇三磷酸（InsP3）门控通道。我们发现，在157个原本无电流的双分子层中，有18个在加入InsP3（1.25至30微摩尔）后出现了电流波动。由InsP3开启的离子通道可分为两组，它们在电导和动力学方面存在差异。一种通道的电导为37皮安，有两个电流水平，较大的单通道电流与较长的开放驻留时间相关。另一种通道显示出更大的电导（103 - 184皮安）。两种类型的通道都显示出接近零毫伏的反转电位，这与非特异性阳离子通道一致。这些实验表明，哺乳动物嗅觉神经元拥有两种类型的纤毛InsP3门控通道。
