Figure 6.

Dendritic spine head size (diameter) for hearing and early deaf FAES neurons. In (A), the average dendritic spine diameter from apical dendrites averaged 0.672 μm for hearing (“H”; gray bar: ±SE) and 0.707 μm for early deaf animals (“D”; black bar), which was statistically different (asterisk, Wilcoxon rank sum, P < 0.001). In (B), the distribution of spine head size is depicted for both the hearing (gray bars) and the early deaf (black bars) animals, where the range of dendritic spine sizes was essentially the same for both treatment groups. Box and whisker plots indicate 25–75% quartiles (box), mean (inside box-vertical line), range of sample (whiskers), and outliers (black dots). For hearing animals, the middle quartiles (25–75%) extended from 0.5 to 0.8, but for early deaf those same quartiles included spine measures from 0.5 to 0.9, indicating that proportionally more spines in the lower range were found in the hearing group. In (C), a cumulative probability distribution is shown for spine diameter values from hearing (gray line) and early deaf (black line) cases, where the lower spine measures (e.g., <0.8 μm) are consistently more prevalent in the hearing group.