Fig. 2.

MPTP-induced loss of TH-positive striatal fibers. In saline-treated control mice, there was no difference in the number of striatal TH-positive fibers among the genotypes DAT-Cre (A and A′), Ret^lx (B and B′), and DAT-Ret^lx/lx (C and C′). In addition, MPTP-induced depletion of TH-positive striatal fibers did not differ among the genotypes DAT-Cre (D and D′), Ret^lx (E and E′), and DAT-Ret^lx/lx (F and F′) at 14 days. Striatal fibers showed regeneration between 14 and 90 days in DAT-Cre (G and G′) and Ret^lx (H and H′) mice but not in DAT-Ret^lx/lx mice (I and I′). (A–I) The entire frontal sections through the striatum stained for TH by using DAB. (A′–I′) Representative higher-resolution images used for the quantification of striatal fibers. (J and K) TH was stained by immunofluorescence. (Scale bar, 25 μm.) The bar graphs summarize the data for the dorsal (J) and ventral (K) striatum from three to four mice per group. Numbers are means ± SD; ANOVA followed by Tukey's post hoc test. n.s., nonsignificant.