Amyloid precursor protein (APP) immunoreactivity in sham and TBI animals. APP-ir profiles are not evident within the corpus callosum (cc) in sham animals (A). One day post-TBI, prominent puncate labelling is present, reflecting accumulation of APP protein within damaged axonal endbulbs (B). This punctate pattern is not present 8 days post-TBI here (C) or in ventrally located white matter tracts such as the anterior commissure (ac) (D). ctx = cortex. Bar = 100 μm.