FIG. 6.

As found in previous studies, morphine increased the percent relative lesion at the injury center (0 μm) relative to vehicle treated controls. This effect was not present in morphine-treated subjects that were pretreated with nor-Binaltorphimine (norBNI). There were no main effects of morphine or norBNI on relative lesion size (A), tissue damage (B), or residual gray matter (C). However, residual white matter was significantly affected by morphine treatment at the center of the lesion, and there was a significant interaction between norBNI and morphine treatment rostral to the injury site (D). Morphine decreased the residual white matter at the center of the lesion, but in the rostral segment, norBNI pretreatment at higher doses blocked the adverse effects of morphine on white matter sparing. Results shown as mean ± SEM. *p < 0.05 for post-hoc tests; # p < 0.05 for planned comparisons.