Combination gene therapy reduces astrocytosis in Ppt1−/− mice. (A) Representative images of GFAP staining in treated animals and controls at 7 mo, examined in the primary motor cortex, VPM/VPL of the thalamus, and ventral horn of the lumbar spinal cord, showing differential patterns of reduction of astrocytosis in intracranially (IC-AAV2/9), intrathecally (IT-AAV2/9), and combination intracranially and intrathecally (IC/IT-AAV2/9) treated Ppt1−/− mice, compared with untreated Ppt1−/− and wild-type control mice. IC/IT-AAV2/9 mice showed an overall greater reduction in astrocytosis than either IC-AAV2/9 or IT-AAV2/9 therapy alone. The dotted lines demarcate the boundary between the gray and white matter in spinal cord sections. [Scale bars, 200 μm and 25 μm (Insets).] (Insets) Selected from corresponding lower-power views. (B) Thresholding image analysis at 3-, 5-, and 7-mo time points showing a significant but treatment-specific pattern of the reduced astrocytosis based on the site of vector administration, with IC/IT-AAV2/9–treated mice showing the greatest overall reduction of astrocytosis. Significance is compared with untreated Ppt1−/− mice. Dots represent scatterplots of individual animals. *P < 0.05, **P < 0.01, ***P < 0.001, one-way ANOVA with post hoc Bonferroni correction. Values shown are mean ± SEM (n = 3 mice per group).