M current
M current is a type of noninactivating potassium current first discovered in bullfrog sympathetic ganglion cells
The M-channel is a voltage-gated K+ channel that is named after the receptor it is influenced by. The M-channel is important in raising the threshold for firing an action potential. It is unique because it is open at rest and even more likely to be open during depolarization. Furthermore, when the muscarinic acetylcholine receptor (MAChR) is activated, the channel closes. The M-channel is a PIP2-regulated ion channel.