Modulation of neuroinflammation in the substantia nigra. Microphotographs of CD68 immunostained coronal brain sections, at the level of the substantia nigra of placebo- (A, a), 2.5 mg/kg (B, b), and 5 mg/kg (C, c) pioglitazone-treated hemiparkinsonian monkeys. Rectangles in A, B and C indicate the location of high magnification images a, b and c. Scale bar: A, B, C = 2 mm; a, b, c = 115 μm. Note the less intense microglial activation in the substantia nigra ipsilateral to MPTP insult in pioglitazone-treated groups. D: CD68-ir nigral quantification results. Analysis showed significantly less microglial activation in the pioglitazone-treated groups versus the placebo group (*ANOVA; P = 0.018).