Figure 7. Representative Hargreaves test data for adult Lewis rats which underwent a quadruple (C5-C8) dorsal root crush injury of the left forepaw or sham surgery.

A baseline reading was recorded a week before surgery and experimental readings were recorded weekly during 1-8 weeks after surgery. As opposed to the sham control group, a longer time (in seconds) was required to elicit a withdrawal response from the injured group a week after surgery and this was sustained throughout the duration of the experiment signifying chronic thermal pain sensory deficit. The data were analyzed by repeated measures ANOVA and expressed as mean ± SEM, *P < 0.05 was statistically significant, n = 4.