title: Maternal separation produces lasting changes in cortisol and behavior in rhesus monkeys.
abstract: Maternal separation (MS), which can lead to hypothalamic pituitary adrenal axis dysfunction and behavioral abnormalities in rhesus monkeys, is frequently used to model early adversity. Whether this deleterious effect on monkeys is reversible by later experience is unknown. In this study, we assessed the basal hair cortisol in rhesus monkeys after 1.5 and 3 y of normal social life following an early separation. These results showed that peer-reared monkeys had significantly lower basal hair cortisol levels than the mother-reared monkeys at both years examined. The plasma cortisol was assessed in the monkeys after 1.5 y of normal social life, and the results indicated that the peak in the peer-reared cortisol response to acute stressors was substantially delayed. In addition, after 3 y of normal social life, abnormal behavioral patterns were identified in the peer-reared monkeys. They showed decreases in locomotion and initiated sitting together, as well as increases in stereotypical behaviors compared with the mother-reared monkeys. These results demonstrate that the deleterious effects of MS on rhesus monkeys cannot be compensated by a later normal social life, suggesting that the effects of MS are long-lasting and that the maternal-separated rhesus monkeys are a good animal model to study early adversity and to investigate the development of psychiatric disorders induced by exposure to early adversity.
authors.affiliation: Key Laboratory of Animal Models and Human Disease Mechanism, [corrected] Kunming Institute of Zoology, Chinese Academy of Sciences, Kunming, Yunnan 650223, People's Republic of China.
authors.forename: Xiaoli
authors.initials: X
authors.lastname: Feng
authors.forename: Lina
authors.initials: L
authors.lastname: Wang
authors.forename: Shangchuan
authors.initials: S
authors.lastname: Yang
authors.forename: Dongdong
authors.initials: D
authors.lastname: Qin
authors.forename: Jianhong
authors.initials: J
authors.lastname: Wang
authors.forename: Chunlu
authors.initials: C
authors.lastname: Li
authors.forename: Longbao
authors.initials: L
authors.lastname: Lv
authors.forename: Yuanye
authors.initials: Y
authors.lastname: Ma
authors.forename: Xintian
authors.initials: X
authors.lastname: Hu
mesh_terms: D000818:Animals; D001522:Behavior, Animal / Q000502:physiology*; D005260:Female; D006197:Hair / Q000378:metabolism; D006854:Hydrocortisone / Q000097:blood / Q000378:metabolism*; D008124:Locomotion / Q000502:physiology; D008253:Macaca mulatta / Q000097:blood / Q000502:physiology*; D013315:Stress, Psychological / Q000097:blood / Q000503:physiopathology*; D013997:Time Factors
chemical_list: D006854:Hydrocortisone