Figure 2. Dose-dependent differentiation of 18β-GA effects on fictive swimming of Xenopus embryos.

In each preparation (n= 7) the concentration was maintained at the specified level (0, 15, 30, 90 μm) for 30 min, and then increased to the next higher concentration. Significant effects on ventral root burst duration (A) occur at lower concentrations (30 μm) than effects on swimming episode duration (B; 90 μm) and swimming cycle period (C; 90 μm). *P < 0.05; **P < 0.01.