the present studies on electrophysiological and pharmacological differences of the three types of ca-currents ( n- , l- and t-types ) in whole-cell clamped , cultured embryonic chick sensory neurons revealed that the majority ( 94 % ) of the ca-currents in the nerve cells were the n-type , omega-conotoxin ( omega ctx , 5 microm ) , a blocker of transmitter release at the presynaptic terminals , induced a complete and irreversible blockage of ca-currents elicited from the resting membrane potential ( -60 mv ) in 29 cells among 58 .
C0206181
presynaptic terminals
C0007634
cells