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Figure 6 A, representative recordings of firing activity from a PLLg neuron during the stimulation of the cupula with a sine wave at 1 Hz (top) and 100 Hz (bottom). B, raster plot of individual afferent neuron activity during the application of 10 s stimuli. The stimulation frequency is indicated on the left. The firing rate was calculated by convolving the spike train with a Gaussian kernel (σ = 5 ms). Of the 11 afferent neuron recordings, 1 showed no firing activity after the initial peak for all the frequencies tested. C, average firing rate (continuous trace: mean; shaded area: SD) of PLLg afferent neurons during the application of periodic stimuli to a connected neuromast. Traces are normalised to the peak of the response to 1 Hz stimulation. D, peak firing rate during the first excitatory half-cycle (grey symbols) and during the entire stimulation (black symbols). Responses are normalised to the peak of the response to 1 Hz stimulation. E, steady state firing rate as a function of stimulation frequency. Responses are normalised to the peak for each stimulation frequency. The steady state was calculated as the peak firing rate during the last stimulation cycle for frequencies below 5 Hz included, and as the average firing rate in the last 500 ms of stimulation for frequencies higher than 5 Hz. F, vector strength values as a function of stimulation frequency. Values were computed in two 3 s long time windows at the beginning (grey symbols) and at the end (black symbols) of the stimulation. Note that a subset of the recordings, for which it was not possible to calculate the final vector strength because of the low number of spikes in the last 3 s of stimulation, were not included in this analysis. Number of neurons from left to right (excluded neurons in parentheses): 10 (1), 8 (1), 8 (1), 6 (2), 7 (1), 5 (2), 7 (1) from 7 zebrafish. For the individual recordings used to calculate the averages shown in (D), see Supporting Information - Expanded dataset (Fig. 6).