a, Coronal section (left) and illustration (right) showing the position of the recording site. LA, lateral nucleus of the amygdala; BA, basal nucleus of the amygdala. b, An example spike sorting showing clusters of candidate spikes (left) and average waveforms of four isolated units (right) from a single tetrode. c, Heat map and classified BLA responses during extinction trials (1-s bins; χ2(2) = 16.204, P = 0.0003029 (CS, n = 190; ABS + CS n = 227 cells). d, e, Average positive responses (d; CS, n = 67; ABS + CS, n = 63 cells) and negative responses (e; CS, n = 36; ABS + CS, n = 84 cells) in the BLA during fear extinction (1-s bins). Mann–Whitney U-test, two-sided: P = 0.3736 for positive responses; P = 0.296 for negative responses. f, g, Pearson’s correlation analysis of BLA positive responses (f; CS, n = 8, ABS + CS, n = 6 mice) or negative responses (g; CS, n = 8, ABS + CS, n = 9 mice) during fear extinction with average freezing level during spontaneous recovery and renewal. h, Proportions of the classified BLA responses (χ2(3) = 2.0536, P = 0.5613). i–k, Averaged pip responses (20-ms bins) of classified fear cells (i; CS, n = 34; ABS + CS, n = 42 cells), resistant cells (j; CS, n = 21; ABS + CS, n = 16 cells) and extinction cells (k; CS, n = 24; ABS + CS, n = 30 cells) during the first extinction trial (left) and the last extinction trial (right). l–n, Time course of averaged pip responses (left) and trial responses (right) of fear cells (l; samples from i), resistant cells (m; samples from j) and extinction cells (n; samples from k) during fear extinction (early, second-to-fifth trials; mid, sixth-to-tenth trials; late, eleventh-to-fifteenth trials). Mixed-design ANOVA for pip responses: F1,74 = 0.513, P = 0.476 for group effect of fear cells; F1,35 = 2.859, P = 0.0998 for group effect of resistant cells; F1,52 = 0.345, P = 0.559 for group effect of extinction cells. Mixed-design ANOVA for trial responses: F1,74 = 4.775, P = 0.032 for group effect of fear cells; F1,35 = 4.846, P = 0.0344 for group effect of resistant cells; F1,52 = 0.638, P = 0.428 for group effect of extinction cells. Mean ± s.e.m.; post hoc multiple comparison with Bonferroni correction. See Supplementary Table 1 for statistical details.