Cat D is upregulated in MPTP caudate nucleus. (A) Taqman qRTPCR for Cat D mRNA was performed on RNA from caudate samples. A significant upregulation in Cat D mRNA is seen. The delta Ct (dCt) method was performed to determine relative concentrations, using the average of the Ct of 18S and GAPDH as the normalizing value. Mean and standard error of the mean shown, significance is indicated by *p < 0.05 (Student's t-test). (B) Photomicrographs of representative sections of caudate of two animals (#1, #2) from each group of the control and MPTP monkeys. Caudate sections were immunohistochemically stained with anti-Cat D. Minimal staining is seen in sections from control animals (bar = 50 μm) and in corresponding increased magnification (40×, bar = 10 μm); whereas, in MPTP treated animal, there is increased staining. Increased magnification (40×, bar = 10 μm) reveals that the staining is seen within neurons in the cell body, axon hillock (bottom right).