Fig. 1

Repeated noxious mechanical stimuli induces aversion to non-noxious stimuli to mimic catastrophizing behavior. A Timeline of behavioral experiments, where either the noxious pin prick (PP) or the non-noxious von Frey (vF) stimulus was applied to the rat’s hind paw during priming, and the vF stimulus was delivered during conditioning. B Rats that were delivered the vF stimuli during priming exhibited no aversion to subsequent vF stimuli (p = 0.6105, paired t test; n = 4 animals) (Preconditioning NS: 306.2 ± 22.39, Preconditioning vF: 293.8 ± 22.39, Testing NS: 323.2 ± 26.50, Testing vF: 276.9 ± 26.50). C Rats that were delivered the PP stimuli during priming exhibited aversion to subsequent vF stimuli (**p < 0.01, paired t test; n = 6 animals) (Preconditioning NS: 293.8 ± 29.27, Preconditioning vF: 306.2 ± 29.26, Testing NS: 457.6 ± 30.42, Testing vF: 143.4 ± 30.16). D Rats primed with PP showed a greater aversion to the vF than did rats primed with vF (*p < 0.05, unpaired t test; n = 4 vF priming animals and n = 6 PP priming animals) (vF: 16.98 ± 29.95, PP: 162.8 ± 31.76). Data are represented as mean ± SEM