Immunofluorescence analysis after SCI. 5-HT staining of the ventral horn (A-C, 5 mm distal to the lesion) is shown for the ADAMTS-4 treatment group (A and B) and vehicle group (C). Higher-magnification of the boxed area in A is shown in B. The arrows in B and C indicate 5-HT-positive fibers. Scale bars, 500 μm (A) and 50 μm (B and C). (D) The 5-HT-positive areas are summarized in the graph. Five rats are used for each group at eight weeks after spinal cord injury. *, P < 0.05. Values are presented as the means ± SD. 5-HT, 5-hydroxytryptamine; SCI, spinal cord injury.