Figure 1

Effect of enriched diet and companionship on hyperalgesia in male sickle and control mice. Mice were fed specific diets from birth until approximately 8 months of age as indicated on the left side of each figure. Diet and/or companion introduction or withdrawal was done for three weeks following baseline testing; specific treatment groups are listed on the right side of the figure. Hyperalgesia measures for all mice are shown for, mechanical hyperalgesia as PWF in response to 1.0 g von Frey filaments; heat hyperalgesia as PWL in response to a heat stimulus; cold hyperalgesia as PWF per 2 min on a cold plate at 4 °C and deep tissue/musculoskeletal hyperalgesia as grip force exerted by forelimbs. (a–d) Male sickle mice (HbSS) given sickle or regular diet in the presence or absence of a female companion. (e–h) Male control mice (HbAA) given sickle or regular diet in the presence or absence of a female companion. (i–l) Male sickle mice (HbSS W) fed sickle diet in the presence of a female companion followed by withdrawal of sickle diet replaced with regular diet and/or withdrawal of the female companion. Regular diet without companionship, RD/C−, nSS = 12, nAA = 8; regular diet with companionship, RD/C+, nSS = 10, nAA = 10; sickle diet without companionship, SD/C−, nSS = 13, nAA = 10; sickle diet with companionship, SD/C+, nSS = 20, nAA = 11; withdrawn from sickle diet, W RD/C+, nSS = 5; withdrawn from companionship, W SD/C−, nSS = 6; withdrawn from sickle diet and companionship, W RD/C−, nSS = 20, nAA = 8; mixed linear models with Tukey’s post-hoc test, *p < 0.05, **p < 0.01, ***p < 0.001 compared to HbSS RD/C−; ^†p < 0.05, ^††p < 0.01, ^†††p < 0.001 compared to HbSS SD/C+. PWF, paw withdrawal frequency; PWL, paw withdrawal latency.