Extended Data Fig. 7: Additional analyses of the microablation-induced effects on single-neuron response dynamics and pairwise signal correlation.

a. Best response amplitude of neurons responsive on both day 5 and day 5±i normalized by the average best response during early baseline days (1 and 3). One-way ANOVA test (mean ± s.e.m. across mice), p > 0.26 for all the three experimental cohorts. b. Exemplary sound-evoked Ca²⁺ transients of neurons which responded to sounds on day 5 and reduced the amplitudes in these responses in following days after ablation in sound responsive ablation (top left), non-sound responsive ablation (middle left), and control (bottom left), respectively. Right: Exemplary sound-evoked Ca²⁺ transients of neurons unresponsive on day 5, but becoming responsive in the following days after ablation. c. Assessing the three-dimensional spatial extent of the microablation-induced effect on normalized best response amplitudes in the spared neurons. In the control cohort, the high category neurons with strong sound-evoked responses that were excluded from the further analysis were considered as reference (see Methods). Spared neurons were split into neurons responsive on day 5 (Left) and neurons gaining responsiveness (Right). In a given mouse, the three-dimensional distance of a spared neuron to each of the 30–40 microablated neurons (or high category neurons in the control cohort) was calculated, that is contributed multiple distance measurements associated with the same effect on the best response amplitude. All distance combinations were categorized into distance bins ranging between 15 and 350 μm. For each distance bin, the corresponding best response amplitude in each neuron was normalized to the average baseline amplitude for each mouse, the normalized best response was averaged across neurons. Data presented as mean ± s.e.m. across neurons (the detail n numbers of neurons in each split group across days for different experimental cohorts were described in Supplementary Table 3.). In the control cohort, normalized best responses of neurons responsive on day 5 gradually decreased over days with generally constant amplitude across distance, but exhibited modest reduction of normalized amplitude on later (day 11 and 15) days (Two-sided t-test between short and long distance, day 1 to day 15: see detail statistics below). Normalized best responses of newly responsive neurons remained rather flat across distance and did not show any systematic change during and after baseline days (Two-sided t-test between short and long distance). d-f. Same as c, but from microablated neurons for sound responsive ablation, for non-responsive ablation, and for inhibitory neuron ablation, respectively. In sound responsive ablation, normalized best responses of neurons responsive on day 5 decreased over days, but with constant amplitude across distance (Two-way ANOVA across distance bins or across days; *** p < 0.001; see Supplementary Table 2.). On the other hand, normalized best responses of newly responsive neurons strongly increased the amplitudes later days (Two-way ANOVA across distance bins or across days; *** p < 0.001). Three days after microablation, the normalized amplitude with nearby distance exhibited larger amplitude than the amplitude distant from ablated neurons (Two-sided t-test between short (< 100 μm) and long distance (250–350 μm), p = 0.49, 0.42, 1.0 × 10⁻⁴, 1.0 × 10⁻⁵, 2.0 × 10⁻⁴, 0.12 for day 1,3,7,9,11,15). For non-sound responsive ablation, normalized best responses of neurons responsive on day 5 decreased over days and the reduction was more prominent at shorter distance from ablated neurons (Two-way ANOVA across distance bins or across days; *** p < 0.001; Two-sided t-test between short and long distance, see details below). On the other hand, normalized best responses of newly responsive neurons did not change over distance, but showed slight increase in amplitude later days after ablation (Two-way ANOVA across distance bins or across days; *** p < 0.001). The normalized amplitude on day 7 was suppressed at shorter distance, but conversely increased later days (Two-sided t-test between short and long distance: see details below). g. Same as Fig. 3e bottom, but normalized tuning curves of day 5 responsive neurons (top) and of neurons unresponsive on day 5 but responsive on the other day (bottom), for sound responsive cohort (left), non-sound responsive cohort (middle) and control cohort (right), respectively (mean ± s.e.m. across mice). h. Same as Fig. 4c, but the colormaps displaying the change in the fraction of high-signal-correlation neuron pairs, one of which was from neurons responsive on both day 5 and any other day, and the other of which was from neurons unresponsive on day 5 but responsive on any other day. i. Change in the fraction of neuron pairs with high signal correlation from baseline at the largest response amplitude bin in the corresponding colormaps in i. Two-sided t-test between baseline days and days after ablation with FDR correction (mean ± s.e.m. across mice; Sound responsive cohort: p = 0.24, 0.067, 0.015, 0.018 for day 7, 9, 11, 15). * p < 0.05. Permutation test for group comparison: p > 0.05 from day 7–11 for all the three cohorts, but p < 0.05 on day 15 for sound responsive cohort. j. Schematic of the procedure to analyze the change in pairwise signal correlations shown in Fig. 5. First, the distributions of all pairwise signal correlations between high category neurons and spared neurons are calculated on a given day (N_all). Note, each spared neuron contributes 30–40 pairwise correlations and vast majority of the spared neurons is categorized as non-responsive on a given day. Thus, the distribution is largely centered around 0 and highly stable over days, as can be seen with small bin sizes (lines, red axis on the left; One-way ANOVA test of cumulative distribution of signal correlation > 0.6 over days; p = 0.82) and coarser bin sizes used for later analysis steps (grey bars, black axis on the right). The inset shows the tail of high pairwise correlations. Second, from this distribution only the neuron pairs between high category neurons and the neurons responsive on day 5 (N_d5, orange histogram) and the neuron pairs between high category neurons and the neurons not responsive on day 5, but responsive on another day (N_gain, blue histogram) are considered and their fraction in the respective bins is calculated (bar stacks on the bottom right shown for day 3). Note, as expected, the pairwise signal correlations for responsive spared neurons are enriched for high signal correlation values. k. Bar stacks of fraction of neuron pairs for all the signal correlation bins over days in sound responsive cohort in Fig. 5a. On day 5, by construction there is no contribution of N_gain neuron pairs. Note, the fractions of N_gain (blue) and N_d5 (orange) neuron pairs shift after microablation towards N_gain neuron pairs. The color maps in Fig. 5 show these changes in fraction over time after normalization to baseline days 1 and 3 by subtraction of the average fraction, as shown in the two leftmost bar stacks. The bars on the left side of the color maps in Fig. 5 show this average baseline value for the respective bins. Data presented as mean ± s.e.m. across mice for a, g, h-i (n = 10 mice for sound responsive ablation, n = 10 mice for non-sound responsive ablation, n = 9 mice for control).