Responses to sound onsets and offsets are distinct in A1 and AAF. (a,b) Thalamocortical slice with CTB-red injected into A1, CTB-green injected into AAF and retrogradely labelled cells in MGB. (c) Thalamocortical slice with schematic indication of MGB, A1, AAF, their neural connections and tonotopy. The color code is as in (d). (d,e) Comparison of response latencies for differently tuned neurons in A1 and AAF. Latencies are color-coded to the neuron’s onset BF (correlation between onset latencies and BF: A1, ρ = −0.4273, p < 0.0001, n = 192; AAF, ρ = −0.0664, p = 0.3476, n = 202; Spearman correlation). (f) Raster plot and peristimulus time histogram (PSTH) of an example A1 (left) and AAF (right) neuron’s response to PTs (frequency varying between 4–48.5 kHz, sound level varying between 0–80 dB SPL, inter-stimulus-intervals equally distributed between 500 and 1000 ms). The blue shaded bar represents the tone presentation. (g,h) Average PSTH (mean ± SD) of A1 and AAF responses to PTs (same sound stimuli as in f). Panels (g–i) depict average responses collapsed across frequencies and sound levels. (i) Average PSTH (mean ± SD) of A1 (red) and AAF (blue) responses to PTs grouped according to their onset BF. (j) Comparison of half decay time (t1/2) of responses in A1 and AAF neurons grouped according to their onset BF. Time of half decay: A1: 17.67 ms (n = 39); 14.9 ms (n = 38); 14.26 ms (n = 63); 11.35 ms (n = 8); AAF: 8.88 ms (n = 71); 8.95 ms (n = 63); 10.42 ms (n = 55); 7.14 ms (n = 4) for neurons with BF < 8 kHz, 8–16 kHz, 16–32 kHz, >32 kHz respectively. Data represent mean ± SEM. ***p = 0.0003, ****p < 0.0001, ns p = 0.1535, Mann-Whitney test.