In article <3ug92d$1sf at mojo.eng.umd.edu>, didier at src.umd.edu says...
>>>frank.le_foll at univ-rouen.fr (Frank Le Foll) writes:
>>>> I'm looking for the origin of the 'A' in the IA nammed potassium channel.
>>>>On page 117, Hille says:
>"Some encoding membranes have an additional K-channel that activates
>transiently [...]. Current in this channel has been variously called
>A-current (IA), fast transient K current, transient outward current
>(Ito), and rapidly inactivating K current."
>>Connor and Stevens coined the term A-current, hence the answer might lie
>in the original article. But Hille's comments seem to point to the fact
>that there's no logical explanation for the 'A'!
>>Connor J.A. and Stevens C.F., Voltage clamp studies of a transient outward
>membrane current in gastropod neural somata, J Physiol (Lond) 213 (1971)
Didier got the original discovery right, and Bertil Hille's book is an
excellent reference for ion channel classification, but the notion that there
is no logical explanation for the A current is inaccurate. This channel has
since been described in several phyla; the gene(s) have been identified, and
the physiology has been explored in many many preps since 1971!
Cheers, W. Michael King