a and b Solid bars = acute stress, white bars = repeated restraint experience. a) Rats that received 10 min of repeated restraint show significant habituation of plasma CORT compared to rats challenged for the first time with 10 min restraint, but show no significant habituation when challenged with 30 min of restraint. b) No significant difference exists between plasma ACTH after 10 min acute or repeated restraint, however previous experience of 10 min restraint on Days 1-4 significantly decreases plasma ACTH response to 30 min restraint duration on test day. (* indicates significant LSD pair-wise comparison between differing restraint experience with same test day duration, p<0.05, n=12).