The specific effect of potassium on transmitter release by motor nerve terminals and its inhibition by calcium

Abstract
1. There exist two distinct effects of potassium on the transmitter release system, one which develops rapidly and another which becomes maximal much more slowly. The fast effect is inhibited by raised Ca2+, which does not inhibit transmitter release evoked by depolarizing pulses. Thus the fast effect is not secondary to nerve terminal depolarization.