Figure 9. Lack of effect of the gap junction blocker 18β-GA (90 μm) on fictive swimming in larvae.

Aa Stage 42 Xenopus larva (Nieuwkoop & Faber, 1956). Ab, excerpts of fictive swimming from near the start of an episode evoked by tail skin stimulation in control saline (upper trace) and 30 min after application of 18β-GA (lower trace). Note long control larval bursts are unaffected by 18β-GA and resemble stage 37/38 activity after gap junction block with 18β-GA (e.g. Figs 1Ab; 3Ab). B, neither ventral root burst duration (Ba) nor swimming episode duration (Bb) was significantly affected by 90 μm 18β-GA (n= 6). Normalized episode duration was calculated by T_Dur/PT_Dur, where PT_Dur and T_Dur are episode duration of pre-treatment and treatment, respectively. Open bars = time 0 (pre-treatment); filled bars =+30 min (18β-GA).