Basal FoxP2 levels are similar between hearing and deafened juveniles.

A) Exemplar hemi-coronal sections show FoxP2 signals detected with either the mid or 3′-probe at 50, 65 and 75d in hearing (H; left hemi-sections) or deaf (D; right hemi-sections) birds. B) Quantification of pixel density within area X, normalized to values of the outlying striatum, reveals stable expression regardless of age or hearing condition. With each probe, at each age, and in each condition (white boxes = hearing, shaded boxes = deaf), values exceed unity (1.0), indicating slightly higher expression within area X. No differences were detected with either probe (Mean±SEM: H-NS vs. D-NS – 3′-probe: 50d, 1.07±0.02 vs. 1.09±0.02; 65d, 1.12±0.03 vs. 1.11±0.02; 75d, 1.18±0.02 vs. 1.15±0.07. Kruskal-Wallis H = 10.7, df = 5, p = 0.06; mid-probe: 50d, 1.08±0.02 vs 1.09±0.01; 65d, 1.06±0.01 vs. 1.03±0.01; 75d, 1.14±0.03 vs. 1.10±0.04. Kruskal-Wallis H = 8.7 p = 0.12). ‘Box and whiskers’ plots show the median (line), average (filled small rectangle), 25^th and 75^th percentiles (box) and 5^th and 95^th percent confidence intervals (whiskers) for each group. The number of birds per group is indicated beneath. For each bird, multiple sections were analyzed, then averaged, to produce a single metric per bird.