Expression of myelin-related mRNA in the human ventral prefrontal white matter. Histograms show significant differences in the expression of A, PLP1; B, CNPase; C, MOG; D, Olig 1 between the subjects with major depressive disorder (MDD) and control subjects. Mean values (with standard error of the means) for subjects with MDD are expressed as percent regulation of the control subjects. *p< 0.05, **p<0.01.