Figure 2. Nocifensive behavior phenotype in FVB and Fmr1-KO mice.

Box plots show median, interquartile range, and 5^th and 95^th percentiles for behavior outcomes in FVB and Fmr1-KO mice. P values refer to comparisons of baseline measurement between strains. Fmr1-KO mice had increased tolerance to noxious heat as they had higher hotplate (A) and tail flick (B) latencies compared to FVB control mice (both p≤0.001). C, Fmr1-KO mice had increased tolerance to noxious cold stimuli as they displayed lower sensitivity to the cold plate compared to FVB animals (p=0.001). D, Fmr1-KO mice, compared to FVB animals, had higher current threshold in response to 5Hz stimulation (p=0.02). In contrast, compared to FVB mice, Fmr1-KO animals had similar sensitivity to 250Hz (E, p=0.19) and 2000Hz (F, p=0.85) electrical stimulation, which recruit myelinated Aδ and Aβ fibers respectively. G, Fmr1-KO mice also displayed significantly greater number of writhes after an intraperitoneal injection of 0.6% acetic acid compared to FVB mice (p=0.024). Age-matched males were investigated as only males have the behavior phenotypes of interest. N≥6 mice (males only) per group for each outcome measurement. indicates p<0.05, † indicates p≤0.01, and ‡ p≤0.001.