Brown D A, Adams P R
Nature. 1980 Feb 14;283(5748):673-6. doi: 10.1038/283673a0.
Cholinergic excitation of vertebrate neurones is frequently mediated through the action of acetylcholine on muscarinic (atropine-sensitve) receptors. This type of excitation differs substantially from the better known nicotinic excitation. One difference is that, instead of an increased membrane conductance, a decreased conductance (to K+ ions) frequently accompanies muscarinic depolarisation. This has been detected in sympathetic, cortical and hippocampal neurones. Using voltage-clamped frog sympathetic neurones we have now identified a distinctive voltage-sensitive K+-current, separate from the delayed rectifier current, as the prime target for muscarinic agonists. We have termed this current the M-current, IM.
脊椎动物神经元的胆碱能兴奋常常是通过乙酰胆碱作用于毒蕈碱型（对阿托品敏感）受体来介导的。这种兴奋类型与更为人熟知的烟碱型兴奋有很大不同。一个不同之处在于，毒蕈碱型去极化常常伴随着电导降低（对钾离子而言），而不是膜电导增加。这已在交感神经、皮层和海马神经元中检测到。利用电压钳制的青蛙交感神经元，我们现已确定一种独特的电压敏感性钾电流，它不同于延迟整流电流，是毒蕈碱型激动剂的主要作用靶点。我们将这种电流称为M电流，即IM。
