Figure 1

Median (and box plots) of the number of 1-min intervals in which young guinea pigs exhibited the passive behaviors of crouching, eye-closure, and extensive piloerection during 3-h separations in a novel enclosure during two consecutive days just prior to weaning and then again 10 days after the first day. The top panel illustrates the sensitization of this response during later separations, and the bottom panel shows the effect of administering the anti-inflammatory naproxen (14 mg/kg) for 3 days just prior to the first separation. Naproxen-injected animals evinced lower levels of passive behavior than did vehicle-injected and non-injected controls during all three separations. Statistically significant differences are indicated by asterisks. Adapted from [64] (top panel) and [65] (bottom panel).