Acetylcholine can act independently of serotonin to induce ventral and dorsal tail curling. (a) Comparison of tail curling in aldicarb of wild-type versus tph-1 (mg280) males (wild-type and tph-1, aldicarb, N = 35; wild-type ddH20, N = 34; tph-1 ddH20, N = 32). (b) Comparison of tail curling in response to aldicarb in lin-39 (n1760), versus wild-type males (wild-type, aldicarb, N = 20; lin-39, aldicarb, N = 18; him-5, ddH20, N = 20; lin-39, ddH20, N = 18). For (a) and (b), the highest amount of tail curling at the 20- to 25-minute time points was averaged. W = water, A = aldicarb, WT = wild-type.