Effects of 1 × 10−6 m oxotremorine M (OXO-M), 1 × 10−6 m propargyl ester of arecaidine (APET), 1 × 10−5 m pirenzepine alone and in combination with 1 × 10−5 m carbachol (CCh), 5 × 10−6 m AF-DX 116 (AFDX) alone and in combination with 1 × 10−5 m carbachol on the quantal contents, minimal latencies, mean modal values of the latency histograms and the P90 parameter in proximal, central and distal regions of the synapse. Values (means ± s.e.m.) from 4–6 endplates were normalized to controls before application of the drugs (1.0). Asterisks indicate the statistically significant differences at P < 0.05.