Extended Data Fig. 8: Calcium dynamics of parallel descending pathways during the singing of pulse and sine song.

a, Time course of ΔF/F recorded from pIP10 (top) and the proportions of pulse and sine song (bottom) during laser stimulation at an irradiance of 575.6 μW/mm². Data are represented as mean ± s.e.m. across neurons (n = 9 flies). b, The mean ΔF/F of pIP10 during the stimulation of the song driver. Each dot represents a fly from which the combined calcium signals of the left and right pIP10 neurons were recorded. Lines represent mean ± s.d. across flies (n = 9 flies). The X-axis is in a logarithmic scale. c, The mean proportions of pulse and sine song during the stimulation period in the recordings from pIP10. Each dot represents a fly. Lines represent mean ± s.d. across flies (n = 9 flies). d–f, Same as a–c but for pMP2 except that the activity of individual neurons was analyzed. (d,e) n = 12 neurons in 7 flies. (f) n = 7 flies. g, Example ΔF/F trace of vPR9 neurons labeled by the vPR9-SS1 line²⁴ (top) together with the simultaneously recorded sound (bottom). Calcium signals were recorded from part of the neurite of vPR9 neurons. h, Time course of ΔF/F of the vPR9 neurons labeled by the vPR9-SS1 line (top) and song (bottom) around song-type transitions. Dashed vertical lines represent the timing of transitions. Data are from 7 flies and represented as mean ± s.e.m. across transitions for both ΔF/F and song (n = 384 and 134 events for pulse-to-sine and sine-to-pulse transitions, respectively). i, The mean change in ΔF/F after song-type transitions relative to ΔF/F before the transitions for the the vPR9 neurons labeled by the vPR9-SS1 line. Each dot represents a fly. Lines represent mean ± s.d. across flies (n = 7 flies). P = 0.32 (pulse-to-sine transitions); P = 0.053 (sine-to-pulse transitions); two-sided one-sample t-test with Bonferroni correction. j–l, Same as g–i but for vPR9 neurons labeled by the vPR9-SS3 line²⁴. (k) Data are from 5 flies (n = 341 and 106 events for pulse-to-sine and sine-to-pulse transitions, respectively). (l) n = 5 flies. P = 1.00 (pulse-to-sine transitions); P = 0.046 (sine-to-pulse transitions).