at concentrations of quinidine higher than 100 microm ( and higher than 1 mm for quinine ) , 1 ) the resting potential shifted to the depolarizing direction with an increase of the input resistance , 2 ) the spike duration was prolonged , 3 ) the spike amplitude was decreased , 4 ) the late component of the afterhyperpolarization ( ahp ) ( caused by the activity of the ca2+-mediated k conductance ) were suppressed , and 5 ) finally , neurons became inexcitable .
C0034414
quinidine
C0034417
quinine