Extended Data Fig. 5: Licking-associated sparse activation of apical dendrites of PT neurons.

a, Top, two-photon Ca²⁺ imaging from apical dendrites of GCaMP6f-expressing PT neurons in S1 in mice drinking a water reward. Bottom, averaged licking response to a water reward delivered through a spout with a random interval independent of whisker detection (n = 162 trials). b, Two examples of Ca²⁺ activities in apical dendrites of PT neurons, indicated in a, aligned by the timing of water deliveries. c, Histograms of dendritic Ca²⁺ responses in PT neurons to a free water reward (light blue; n = 293 dendrites from 3 mice) versus those to a reward upon detection of whisker stimuli, that is, hit trials (dark blue; n = 359 dendrites from 6 mice). Mann-Whitney U test. d, Top, Ca²⁺ response in reward-only trials versus hit trials aligned by the timing of first licks, averaged across dendrites that were significantly active in those trials compared with catch trials (mean ± s.e.m., n = 95 dendrites from 3 mice and 176 dendrites from 6 mice for reward-only and hit trials, respectively; ***P = 8.1 × 10⁻⁶). Bottom, histogram of the Ca²⁺ onset timings (P = 0.086). Mann-Whitney U test.