Definition of ion channel
: a cell membrane channel that is selectively permeable to certain ions (as of calcium or sodium)
First Known Use of ion channel
Medical Definition of ion channel
: a cell membrane channel that is selectively permeable to certain ions (such as of calcium or sodium) <Researchers now know that not only do all cells, including nerve cells, have ion channels through which substances such as sodium and calcium move in and out, but that particular subtypes of sodium channels govern the transmission of pain.—Judy Foreman, The Los Angeles Times, 24 Nov. 2003>
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