ICM AAV delivery transduced cells and brain cell responses. (A) Quantification of VEGF-C and p-VEGFR-3 levels in brain sample lysates using ELISA. ***P < 0.001; **P < 0.005; *P < 0.05 n = 4 mice/group at 2 wk n = 8–11/group at 4 wk. (B–E) Phenotype of brain cells transduced after ICM injection of AAV9-GFP. (B) Tile scans of GFP expression on sagittal (left panel) and coronal (right panel) sections of the adult brain. Note the intracerebral GFP expression at the level of the olfactory bulb (OB), accessory olfactory bulb (AOB), frontal cortex (FCx), retrosplenial cortex (RSCx), hippocampus (Hi), and pretectum (PrT). IVth V: fourth ventricle. (C and D) GFP is detected in SMA⁺ vascular smooth muscle cells (C), but not in PDLX⁺ endothelial cells and CD206⁺ perivascular macrophages (D). Right panel in C and D: Representative intensity profile plots for GFP (green), a-SMA (gray), PDLX (red), and CD206 (purple), taken from a cross section (white arrow) of the images shown in C and D. Note the co-localization or exclusion of GFP expression with a-SMA and PDLX/CD206 markers, respectively. (E) Neural GFP expression is detected in subsets of NeuN⁺ neurons, Olig2⁺ oligodendroglial cells, and very few GFAP⁺ astrocytes (E). Scale bar: 500 μm (B); B–D: 50 μm (C–E). (F) Representative images of subventricular zone (SVZ) Nestin⁺ neural stem/progenitor cells, KI6⁷⁺ dividing cells and DCX⁺ neuroblasts. LV: lateral ventricle; ST: striatum. (G) Quantification of Nestin⁺ cells (% SVZ area: AAV-VEGF-C: 6.2 ± 0.9; AAV-control: 4.5 ± 1.1, P = 0.4), KI67⁺ cells (number of cells/surface unit: AAV-VEGF-C: 33 ± 4; AAV-control: 16 ± 7, P = 0.07) and DCX⁺ neuroblasts (% SVZ area: AAV-VEGF-C: 4.6 ± 0.5; AAV-control: 1.7 ± 0.3 **P = 0.004) at 7 days after AAV administration. Data shown as mean ± SEM, n = 5–6 mice/group. Scale bar: 100 μm (F).