Whisker trimming decreases density of myelinated axons in the barrel and septal/barrel wall regions. Control (A) and deprived (B) tissue at P60 stained for myelin. Myelination is significantly reduced in the barrel hollow region of the sensory-deprived animals in the P30-P60 trim group and in the Trim30/Regrow30 group [F(13,64) = 36.369, p < 0.001] (C). Myelination is significantly reduced in the septal/barrel wall region of sensory-deprived animals at P60, and in the P30-P60 trim group, Trim30/Regrow30 group, and an increase in the P90-P120 trim group [F(13,64) = 51.015, p < 0.001] (D). Bars represent population means and one standard error of the mean. [Color figure can be viewed in the online issue, which is available at wileyonlinelibrary.com.]