Role of TGF-β1 in mediating spinal astrocytic reaction. A: Peripheral nerve injury induced an astrocytic activation at the ipsilateral side DH and VH evidenced by an increase of GFAP immunoreactivity. 5 μg TGF-β1 infusion for 14 days significantly reduced the increase in GFAP ir, whereas the effect of 2 μg TGF-β1 was negligible. B: Intensity of GFAP signal determined as average pixel intensity at specific area of interests on L5 section at 14 days after injury. Data are shown as means ± SEM. *p < 0.05, ***p < 0.001, TGF-β1 treated vs. saline treated in their respective region. ###p < 0.001, ipsi- vs. contra-lateral sides within the same group. Scale bar: 100 μm.