SCI induced significant elevation in Rat Grimace Scale (RGS). (A) Grimace scores increase significantly after SCI compared to baseline and LAM controls (*p ≤ 0.05, one-way analysis of variance). (B) Individual scores subdivided by group indicate that the animals in the LAM group have a grimace score below 0.7, whereas a subset of animals from the SCI group have a grimace score of 0.7 or higher, indicating spontaneous pain sensations. (C) Fifty percent of animals in the SCI group demonstrate spontaneous pain sensations according to the RGS by having a score of 0.7 of higher. SCI, spinal cord injury; LAM, laminectomy.