Fig. 7. (A,B) Representative trace of the tetrodotoxin (TTX)-insensitive responses to UTP (100 µmol l^–1) in (A) prometamorphic stomach and (B) metamorphic stomach. (C) Representative trace of the partially TTX-sensitive response to UTP (100 µmol l^–1) in juvenile stomach. (D,E) TTX (1 µmol l^–1) blocks the UTP-induced decrease in frequency (D, N=9) but not the increase in mean force (E, N=6) in juvenile stomach. (F) L-NAME (300 µmol l^–1) blocks the UTP-induced decrease in frequency (N=5) in juvenile stomach. Statistical analysis was performed using repeated measures one-way ANOVA followed by Bonferroni's post hoc test. Asterisk indicates P<0.05. W, wash-out.