Figure 4. Early changes in PV-mediated inhibitory strength predict eventual recovery of cortical sound processing after nerve damage.
(A–B) PV-mediated inhibition strength (A) and change in spontaneous firing rate (B) timelines for sound exposed, ouabain recovered and ouabain non-recovered mice (red, blue and teal accordingly, plotted for visualization purposes as a fourth order polynomial fit to the data presented Figures 2 and 3). (Middle and Right) Correlation between broadband noise threshold at day 50 and PV-mediated inhibition (A) or spontaneous firing rate change (B) at days 6–10 for ouabain-treated (middle) and sound-exposed mice (right, Spearman’s correlation coefficient, Rs). Each symbol represents a single RS unit. The shape and color correspond to a particular group, as described above. The shading corresponds to a particular mouse within that group.
Figure 4—figure supplement 1. Auditory cortex units show robust PV-mediated inhibition and low-threshold sensory responses prior to nerve damage, both of which are unrelated to the eventual response thresholds after nerve damage.
(A) Distribution of best frequency values for primary auditory cortex units recorded before nerve damage. RS units recorded in noise-exposed mice were targeted to a high-frequency region of the tonotopic map, in the zone of putative cochlear denervation. (B–C) Histogram of PV-mediated inhibition strength (B) and response threshold (C) distributions prior to auditory nerve damage. (D) The strength of PV-mediated inhibition and auditory response thresholds are not correlated with each other before nerve damage (Pearson’s correlation coefficient). (E–F) PV-mediated inhibition strength and auditory response thresholds after nerve damage cannot be predicted from the strength of PV-mediated inhibition before nerve damage (Pearson’s correlation coefficient).