Fig. 1. Effects of CP55940 on locomotion, thermoregulation, and nociception in Young–adult (4 m) and old (22 m) C57BL/6 mice.

CP55940 was administered via intraperitoneal injection at doses ranging from 0.001 to 0.8 mg/kg to young and old male and female mice. Individual data points for each testing group are overlaid on Tukey-style boxplots. The lower and upper edges of each box represent the first and third quartiles, respectively. The middle horizontal line in each box depicts the median of that dose/age group. Sample sizes for every treatment group and figure panel are listed in Supplementary Fig. 5. Statistical comparisons of age, dose, and age:dose interactions were made using the nonparametric Scheirer–Ray–Hare test. Significant omnibus results were followed by planned post hoc contrasts of each dose vs. vehicle-treated control groups using Dunn’s method. The false discovery rate was corrected for using the Benjamini, Hochberg, and Yekutieli method. Within an age group, significant differences (P < 0.05) between a given dose and the vehicle response (0 dose) are indicated using asterisks (*). Differences between age groups at a given dose are indicated by pound signs (#). a, b Total locomotion and fecal output during open-field testing, 30–60 min after injection of CP55940 or vehicle. c Latency to exhibit nociceptive behavior when place on a 52 °C hot plate. d Latency to withdraw the tail from 46 °C water. e Change in rectal temperature 60 m after injection of drug. f Change in infrared recording of skin/pelage temperature 60 m after injection of drug.