Figure 9. Residual TH and AADC expression in the MPTP lesioned monkey brain.

Pre-commissural and post-commissural caudate-putamen, and the substantia nigra stained for TH (A–C) or AADC (D–F) from the intact (A,D), GFP-GCH1 (B,E) and TH-GCH1 (C,F) groups. Insets are high-power images from the left and right hemisphere respectively. MPTP was administered via the right intracarotid artery and by systemic doses until stable parkinsonian impairments were obtained, which varied between the individual monkeys. Two out of six monkeys had spared dopaminergic innervation on the contralateral side to the intracarotid injections (as shown in C), whereas the remaining four were severely lesioned in both hemispheres (as shown in B,E). Since the number of TH and AADC positive cells in ventral tier of substantia nigra in B and C was greatly reduced, the high power insets are from the dorsal tier. TH expression observed in B and C was not vector-derived. CN = caudate nucleus, ic = internal capsule, Put = putamen, SN = substantia nigra. Scale bars in A (that also applies to A′) and A′′ represent 2 mm. Scale bar in the high-power inset Put-L represent 0.5 mm, whereas it represents 0.25 mm in SN-L and SN-R.