A-F) Shown are horizontal (longitudinal) sections through the center of the spinal cords of uninjured mice (0) and at progressively increasing times after injury. Left is rostral. In uninjured mice (A) very little ADAM8 immunostaining is seen. Positive structures appeared to be blood vessels as shown in the inset. At 1 and 3 days post-injury (B,C), some ADAM8-positive structures can be seen around the epicenter (*), which itself appears devoid of staining. From 7 days onward, progressively more staining appears, particularly in the epicenter (D-F), the site where lost tissue is replaced by a fibroblast- and laminin-rich cell matrix. At all post-injury times ADAM8-positive blood vessels could be seen often times in the penumbra (insets). G) The area occupied by ADAM8-positive structures in horizontal sections throughout the dorso-ventral extent of the spinal cord shows that the increase becomes significantly different from the uninjured controls by 7 days post-injury. Data are means plus standard deviation; n = 4 each.