Effects of honokiol and magnolol on glutamate-induced c-Fos protein expression in the spinal dorsal horn of the side ipsilateral to the injection. Photomicrographs illustrating the four experimental groups are represented: corn oil i.p.+saline i.pl. (A), corn oil i.p.+glutamate i.pl. (B), honokiol (10 mg/kg) i.p.+glutamate i.pl. (C), and magnolol (10 mg/kg) i.p.+glutamate i.pl. (D). Summary data of glutamate-induced c-Fos protein expression after honokiol and magnolol treatment in superficial (I-II) spinal cord (E). Values are means ± S.E.M. (n = 4). # indicates significantly different from corn oil-saline group, #P < 0.05; * indicates significantly different from corn oil-glutamate group, *P < 0.05. Statistical analysis was determined by one-way ANOVA followed by a Student-Newman-Keuls post-hoc test. Scale bar = 100 μm.