Figure 5: Representative photomicrographs (a) showing that the valproic acid (VA) treatment (50 mg/kg) reverses the decreased immunoreactivity for tyrosine hydroxylase (TH) of the 6-OHDA group, in the rat mesencephalon lesioned (ipsilateral) side. SO means the sham-operated group, where a high immunoreactivity for TH is observed in both the contralateral (cont., unlesioned) and ipsilateral (ips., lesioned) sides. Scale bars represent 500 μm (magnification ×400). Measurements (b) by Image J software of relative optical densities from 3–5 fields: a. versus SO, ; b. versus 6-OHDA + VA25, ; c. versus 6-OHDA + VA50, ; d. versus SO, ; e. versus SO, (one-way ANOVA and Newman-Keuls as the post hoc test).