Fig. 3: The recruitment of steering neurons was correlated to tail-bending amplitude.

a–c Paired whole-cell patch-clamp recordings between a steering V2a neuron in the MiV1 and a steering V0d neuron in the CaD (a) reveal that the two neurons simultaneously discharged action potentials during an ipsilateral steering turn (b). The steering V2a and V0d neurons are electrically coupled through gap junctions (c). d–f Paired whole-cell patch-clamp recordings between a steering V2a neuron in MiV2 and a steering V0d neuron in CaD (d) reveal that the two neurons were simultaneously recruited during an ipsilateral steering turn (e). The steering V2a and V0d neurons are electrically coupled through gap junctions (f). g–j Graphs showing the recruitment tail angle for the steering V2a neurons in MiV1 (N = 19 neurons from 19 preparations, n = 318 events), MiV2 (N = 9 neurons from 9 preparations, n = 138 events), and the steering V0d neurons in CaD (N = 13 neurons from 13 preparations, n = 200 events) during a steering turn. Statistical graph showing the minimal recruitment angles for the above neurons in (g–j). k–n Graphs showing a linear relationship between tail angle and the number of action potentials generated in the recorded steering V2a neurons (k) and V0d neurons (m). No such relationship exists between tail beat frequency and the number of action potentials generated in the steering V2a neurons (l) and V0d neurons (n). A two-sided test was applied to determine the strength and direction of the correlation. The coefficient of determination (R²) represents the proportion of variance explained by the model, and the P value evaluates the statistical significance of the correlation. P < 0.05 was considered statistically significant.