Figure - PMC

Skip to main content

An official website of the United States government

Here's how you know

Here's how you know

Official websites use .gov
A .gov website belongs to an official government organization in the United States.

Secure .gov websites use HTTPS
A lock ( ) or https:// means you've safely connected to the .gov website. Share sensitive information only on official, secure websites.

View full-text article in PMC

. 2018 Jan 12;7:e29275. doi: 10.7554/eLife.29275

Search in PMC
Search in PubMed
View in NLM Catalog
Add to search

© 2018, Jean et al

This article is distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use and redistribution provided that the original author and source are credited.

PMC Copyright notice

Figure 11. — (A) Intensity coding was largely preserved for suprathreshold sound stimulation: rate-level functions (average increase in spike rate with stimulus intensity) of SGNs in response to 50 ms tone bursts at C_f at 5 Hz corroborated the notion of increased sound threshold but were otherwise comparable in RBE^KO/KO (n = 24 SGNs, N = 8) and RBE^WT/WT (n = 19 SGNs, N = 7) mice, for quantification see Figure 11—figure supplement 1C. (B) Average PSTH recorded in response to 50 × 500 ms tone bursts at C_f and 30 dB above threshold at a stimulus rate of 0.5 Hz (bin width = 2 ms): the onset response to this stimulus was preserved better in RBE^KO/KO SGNs (n = 18 SGNs, N = 7) as compared to higher stimulation rates (Figure 9), but it was still lower than in RBE^WT/WT SGNs (n = 19 SGNs, N = 7), as well as the adapted firing rate. Mean (line) ± S.E.M. (shaded areas) are displayed. (C) Scatterplot of peak (highest 2 ms bin) and adapted (averaged 405–415 ms from response onset) firing rates: significantly reduced peak (p=0.0005, t-test) and adapted (p<0.0001, Mann-Whitney-Wilcoxon test) rates in RBE^KO/^KO SGNs. Box plots show 10, 25, 50, 75 and 90^th percentiles and means are shown as crosses, as for (D). (D) Temporal precision and reliability of sound coding is impaired in RBE^KO/KO SGNs. Synchronization of firing to stimulus and firing rates (reflecting spike probability) were reduced when probed with amplitude-modulated (transposed) tones (continuous stimulation with a carrier frequency at C_f and at a modulation frequency of 500 Hz) (p=0.0043, t-test, for synchronization index, and p<0.0001, t-test, for firing rate, when comparing RBE^KO/KO (n = 22 SGNs, N = 7) and RBE^WT/WT (n = 15 SGNs, N = 6) SGNs). (E) Forward masking experiments were used to study presynaptic SV dynamics: a stimulus complex consisting of a 100 ms masker stimulus, a silent interval of 4/16/64/256 ms and a 15 ms probe (both at the characteristic frequency, 30 dB above threshold) was presented at 2 Hz. The averaged data after alignment of RBE^WT/WT (n = 24 SGNs, N = 7, black) and RBE^KO/KO (n = 27 SGNs, N = 8, red) SGNs responses are displayed as described in Materials and methods. On top of the data we present a fit of a biophysical model (light gray and pink lines) to the data used to study the SV dynamics at the AZ. The refilling and fusion rate constant during spontaneous and stimulated conditions as well as the number of occupied release sites are provided in Table 2. (F) Recovery of onset response showed as ratio of probe and masker response (number of spikes during first 10 ms, mean ± S.E.M), and prediction (dashed lines) derived from the model fit shown in (E). Recovery was slower in RBE^KO/KO SGNs (n = 27 SGNs, N = 8) as compared to RBE^WT/WT (n = 24 SGNs, N = 7) with significant differences in the ratio after 4 ms (p=0.0019, t-test), 16 ms (p<0.0001, Mann-Whitney-Wilcoxon test), and 64 ms masker-probe intervals (p<0.0001, Mann-Whitney-Wilcoxon test), but not after 256 ms (p=0.0835, t-test).

Figure 11—figure supplement 1. — (A) Intensity coding was largely preserved for suprathreshold sound stimulation: rate-level functions (average increase in spike rate with stimulus intensity) of SGNs in response to 50 ms tone bursts at C_f at 5 Hz corroborated the notion of increased sound threshold but were otherwise comparable in RBE^KO/KO (n = 24 SGNs, N = 8) and RBE^WT/WT (n = 19 SGNs, N = 7) mice, for quantification see Figure 11—figure supplement 1C. (B) Average PSTH recorded in response to 50 × 500 ms tone bursts at C_f and 30 dB above threshold at a stimulus rate of 0.5 Hz (bin width = 2 ms): the onset response to this stimulus was preserved better in RBE^KO/KO SGNs (n = 18 SGNs, N = 7) as compared to higher stimulation rates (Figure 9), but it was still lower than in RBE^WT/WT SGNs (n = 19 SGNs, N = 7), as well as the adapted firing rate. Mean (line) ± S.E.M. (shaded areas) are displayed. (C) Scatterplot of peak (highest 2 ms bin) and adapted (averaged 405–415 ms from response onset) firing rates: significantly reduced peak (p=0.0005, t-test) and adapted (p<0.0001, Mann-Whitney-Wilcoxon test) rates in RBE^KO/^KO SGNs. Box plots show 10, 25, 50, 75 and 90^th percentiles and means are shown as crosses, as for (D). (D) Temporal precision and reliability of sound coding is impaired in RBE^KO/KO SGNs. Synchronization of firing to stimulus and firing rates (reflecting spike probability) were reduced when probed with amplitude-modulated (transposed) tones (continuous stimulation with a carrier frequency at C_f and at a modulation frequency of 500 Hz) (p=0.0043, t-test, for synchronization index, and p<0.0001, t-test, for firing rate, when comparing RBE^KO/KO (n = 22 SGNs, N = 7) and RBE^WT/WT (n = 15 SGNs, N = 6) SGNs). (E) Forward masking experiments were used to study presynaptic SV dynamics: a stimulus complex consisting of a 100 ms masker stimulus, a silent interval of 4/16/64/256 ms and a 15 ms probe (both at the characteristic frequency, 30 dB above threshold) was presented at 2 Hz. The averaged data after alignment of RBE^WT/WT (n = 24 SGNs, N = 7, black) and RBE^KO/KO (n = 27 SGNs, N = 8, red) SGNs responses are displayed as described in Materials and methods. On top of the data we present a fit of a biophysical model (light gray and pink lines) to the data used to study the SV dynamics at the AZ. The refilling and fusion rate constant during spontaneous and stimulated conditions as well as the number of occupied release sites are provided in Table 2. (F) Recovery of onset response showed as ratio of probe and masker response (number of spikes during first 10 ms, mean ± S.E.M), and prediction (dashed lines) derived from the model fit shown in (E). Recovery was slower in RBE^KO/KO SGNs (n = 27 SGNs, N = 8) as compared to RBE^WT/WT (n = 24 SGNs, N = 7) with significant differences in the ratio after 4 ms (p=0.0019, t-test), 16 ms (p<0.0001, Mann-Whitney-Wilcoxon test), and 64 ms masker-probe intervals (p<0.0001, Mann-Whitney-Wilcoxon test), but not after 256 ms (p=0.0835, t-test).