Blood corticosterone concentration for post-weaning males (top panel) and females (bottom panel) in both the basal (white bars) and stressed (black bars) conditions. Basal rats are subdivided into undisturbed (N=4M, 5F), handle (N=6M, 6F), and needle prick (N=5M, 6F) conditions. Stressed rats are likewise subdivided into undisturbed (N=4M, 4F), handle (N=5M, 5F), and needle prick (N=5M, 4F) groups. * represents a statistically significant difference from each respective basal group. These data show that acute stress, but not neonatal pain produce general increases in blood stress hormone levels.