Figure 6
From: High-fat diet increases pain behaviors in rats with or without obesity
A shorter exposure to high-fat diet has a more modest effect on pain behaviors in the low dose DRG inflammation model. Sprague-Dawley rats were maintained on normal chow until reaching a weight of ~280 grams, to have age and weight comparable to animals in the previous experiments at the time the pain model was implemented. One week before the low dose DRG inflammation model was implemented, half the rats were switched to the high-fat diet, which was continued until one week after the pain model was implemented. After the behavior measurements on POD 7, the diets of the two groups were switched and behaviors measured for another 2 weeks. The short term (day −7 to 7) high-fat diet group responded to the DRG inflammation with a more modest decrease (compare to Fig. 5) in the von Frey threshold (A) that differed significantly from the normal chow group on POD 1 and 3. The groups did not significantly differ for the dynamic allodynia (B), cold allodynia (C), or guarding behavior (D) tests. For ease of comparison, graphs have the same y-axis scales as Figs 4 and 5. N = 8 male Sprague-Dawley rats per group. **p < 0.01; ***p < 0.001; significant difference between groups at indicated time points (2-way repeated measure ANOVA with Sidak’s multiple comparison posttest; F(1,14) = 5.24 (A), 1.52 (B), 2.13 (C), 3.56 (D)).
