Effects of FK866 treatment on myelin structure alteration. Myelin structure was observed by Luxol fast blue staining. At 24 h after the injury in SCI operated mice (b) a loss of myelin was observed. In contrast in FK866 (c) treated mice myelin degradation was attenuated. No significant alterations was observed in sections obtained by sham groups (a). Moreover Weigert's and Oil Red staining is highly specific for degenerating myelin and for myelin that has been ingested by macrophages. At 24 h after injury, in SCI mice group was observed a greater density of Oil Red staining as a marker for myelin destruction (b1) when compared with control mice (a1). In contrast in FK866 (c1) treated mice myelin degradation was attenuated. In order in the spinal cord tissue collected from SCI mice, was observed the alteration of morphology of neurons when compared with sham-operated mice (b2). A protection against alteration of neuron's morphology was observed in mice group treated with FK866 (c2). This figure is representative of at least 3 experiments performed on different experimental days.