The microglial response to 6-OHDA injection was significantly attenuated in the striatum of COXIB treated animals. Photomicrographs of activated microglia immunohistochemistry in a representative striatal section of a vehicle (A, B) and a COXIB (C, D) treated animal 12 days after the injection of 6-OHDA. All images are ipsilateral to the injection side. E, F) Bar graphs showing the stereological quantification of activated microglia cell density at 12 (E) and 21 days (F). Microglial density was significantly reduced in the striatum of COXIB treated rats (treatment effect p < 0.05) both in the lesioned and in the contralateral striata. However, the microglia response was not completely abolished in COXIB treated animals, as microglia density was significantly higher in the 6-OHDA injected striatum (p < 0.01) and the density was higher in the lesioned/treated striatum than in the contralateral/untreated striatum (p < 0.05). Scale bar: 100 μm for A and C and 25 μm for B and D.