(A,B) Representative photomicrographs of 5-HT immunostaining in the lumbar dorsal horn in VEH (n=5) and PLZ (n=5) treated animals. Scale bar in E=100μm, applies in A-E. (A’,B’ inset) Higher magnification of superficial dorsal horn 5-HT staining. Scale bar=20μm. (C) Quantification (integrated density) of 5-HT+ immunoreactivity in the superficial (laminae I-II) of the bilaterally averaged dorsal horns (t-test, *p=0.020). (D,E) Representative photomicrographs of 5-HT immunostaining in the lumbar ventral horn (VH). (F) Quantification (integrated density) of 5-HT+ immunoreactivity in the (bilaterally averaged) ventral horn. (t-test, NS p=0.209)