Spontaneous miniature end-plate currents (MEPC) and acetylcholine-induced noise were recorded in muscle fibres of m. longitudinalis linguae of lamprey. The MEPC decay time constant was 5.3 ms and amplitude 2.2 nA. The mean channel life time was 3.6 ms and conductance 13.6 pS. Ionic channels in synaptic and extrasynaptic zones had identical kinetics. Inhibition of acetylcholinesterase induced a 2.2-fold prolongation of MEPC, but did not affect the channel life time.