Social housing conditions around puberty determine later changes in plasma cortisol levels and behavior.
A recent study found that male guinea pigs raised in large, mixed age/sex groups exhibited an unexpected suppression of their cortisol response at 4 mo of age. The present study examined the effect of social experience around the time of puberty on cortisol response suppression and social behavior at 4 mo of age. Males reared in large, mixed age/sex groups were either pair-housed with a female or moved to another large colony at 55 days of age. When tested at 4 mo, pair-housed males exhibited much higher levels of courtship and sexual behavior than did colony-housed males, and a shorter latency to begin courtship when with an unfamiliar adult female. In addition, pair-housed males showed much higher levels of agonistic behavior and a shorter latency to escalated aggression with an unfamiliar adult male. Pair-housed males also had lower basal cortisol concentrations and exhibited a greater increment in cortisol levels when isolated in a novel cage than did colony-housed males. Finally, pair-housed males showed a smaller increment in cortisol levels when with the stimulus female or male than when isolated, but colony-housed males did not. The findings demonstrate that social housing conditions around the time of puberty can have pervasive effects on social behavior and hypothalamic-pituitary-adrenal (HPA) activity in 4-mo-old males. Further, these findings are consistent with the notion that changes in HPA activity contribute to social behavior development beyond the time of sexual maturity.
Kaiser
Sylvia
S
Department of Behavioural Biology, University of Muenster, Badestrasse 9, 48149 Muenster, Germany.
Harderthauer
Simone
S
Sachser
Norbert
N
Hennessy
Michael B
MB
D000222:Adaptation, Physiological; D000367:Age Factors; D000818:Animals; D006168:Guinea Pigs; D006799:Housing, Animal; D006854:Hydrocortisone / Q000097:blood*; D007030:Hypothalamo-Hypophyseal System / Q000502:physiology; D008297:Male; D010913:Pituitary-Adrenal System / Q000502:physiology; D012726:Sexual Behavior, Animal / Q000502:physiology*; D012741:Sexual Maturation / Q000502:physiology*; D012919:Social Behavior; D012931:Social Environment; D013997:Time Factors
D006854:Hydrocortisone