Schematic drawing of the experimental set up. The sciatic nerve was transected and immediately repaired. Axonal outgrowth was evaluated by measuring the length of neurofilaments (NF). The numbers of activated (Activating Transcription Factor 3; ATF3) and apoptotic (cleaved caspase 3) Schwann cells were measured just distal to the lesion site (i.e. axons presented) and in the distal nerve segment (distal to the most distal parts of the neurofilament stained axons).