Effect of MK801 on activated kinases. The spinal cord extract were immunoblotted for the -phosphorylated form of ERK. pERK1/2 is up-regulated in injured mice compared with Sham-operated mice (a and a1). Spinal cord levels of pERK1/2 were significantly attenuated in MK801 (2 mg/kg 30 min and 6 h after SCI induction)-treated mice compared with SCI animals (a and a1). Moreover, SCI caused also a significant increase in phospho-p38 expression at 24 h after trauma (b and b1). The MK801 treatment (2 mg/kg 30 min and 6 h after SCI induction) significantly reduced p38 expression (b and b1). The relative expression of the protein band was standardized for densitometry analysis to α-tubulin levels and reported in a1, and b1. *p < 0.05 and **p < 0.01 vs. Sham; #p < 0.05 and ##p < 0.01 vs SCI.