Fig. 2. Immunohistochemical analysis using the pain markers in the laminae I-II layers of the ipsilateral L4∼L5 spinal dorsal horns in the three neuropathic pain models.

The laminae I∼II layers of the ipsilateral L4∼L5 spinal dorsal horns in CCI and SNL models were dissected and sampled on 4 weeks, while those layers in SNI models dissected on 8 weeks after transplantation of hUCB-MSCs. The number of cells positive for pain-related antibodies such as c-fos, CGRP, p-ERK and p-p38 was decreased in the hUCB-MSCs group (n=11 in CCI, n=10 in SNL, n=12 in SNI) compared to control group (n=6 in CCI, n=7 in SNL, n=6 in SNI). Positive cells area (%) presents the mean percentages of c-fos or CGRP or p-ERK or p-p38-immunoreactive (IR) neurons relative to the total number of neurons in the laminae I∼II layers of the ipsilateral L4∼L5 spinal dorsal horns. Statistical significance of difference was determined by Duncan's t-test. A p<0.05 was regarded as statistically significant. The data are presented as mean±S.E.M. ^*p<0.05, ^**p<0.01 and ^***p<0.001 indicate a significant difference compared to control group. All of the micro-graphics are from the CCI group. A, c-fos; B, CGRP; C, p-ERK; D, p-p38. Scale bars, 200 µm