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.

Salivary and hair glucocorticoids and sleep in very preterm children during school age

“…Studies with children born very preterm and animal models of early life adversities show similar HPA axis alterations -often involving persistent down-regulation of HPA axis activity (Feng et al, 2011;Kaseva et al, 2014). School aged children born very preterm or with very-low-birth-weight (VLBW; < 1500 g) show lower diurnal cortisol profiles (Wadsby et al, 2014), faster decreasing cortisol levels in the evening , and decreased salivary cortisol responses to social stress (Buske-Kirschbaum et al, 2007), which is also consistent with findings in adults (Kaseva et al, 2014).…”

Social rank and cortisol among female rhesus macaques ( Macaca mulatta )

“…Likewise, hair follicles can be used to track cortisol levels over time, with the most proximal 1 cm segment to the scalp approximates the last month's cortisol production, the second most proximal 1 cm segment approximates the cortisol production during the month before that, and so on (Wennig, 2000). This makes cortisol measured in hair a biomarker of chronic stress, as demonstrated previously in two studies of rhesus macaques in which hair samples were obtained to assess long-term stress levels (Davenport et al, 2006;Feng et al, 2011). Moreover, hair samples are easily transported and stored in envelopes or vials at room temperature for years, and gathering the samples does not affect stress levels of the subjects (Gow et al, 2010;Russell et al, 2011).…”

“…More importantly, however, these cortisol levels only reflect short-term stress that occur over hours to days, and without the repeated sampling of animals, they cannot assess chronic stress levels that occur over weeks to months long periods (Keay et al, 2006;Owen et al, 2005). Cortisol measured in hair, meanwhile, has been considered a biomarker of chronic stress and has proved useful in two studies of rhesus macaques in which hair samples were obtained to assess long-term cortisol and stress levels (Davenport et al, 2006;Feng et al, 2011). To our knowledge, this is the first study using cortisol measurements from hair sampling to evaluate the relationship between social rank and long-term stress in female rhesus monkeys, offering novel insight into longterm stress that arises from social.…”

“…The hair cortisol extraction was done as described in detail in previous studies (Davenport et al, 2006;Feng et al, 2011). Briefly, 500 mg of hair sample was washed twice for 3 min each time in 10 mL isopropanol to remove surface contaminants, dried at 37 °C for 8 hours, and then pulverized using a Retsch ball mill (Retsch M400) at 26 Hz for 2.5 min.…”

Epigenética, Cuidados Maternais e Vulnerabilidade ao Estresse: Conceitos Básicos e Aplicabilidade

“…Estes infl uenciam de modo persistente alterações epigenéticas e têm sido considerados como importantes determinantes da resistência ou vulnerabilidade da prole a eventos estressores (Beery & Francis, 2011;Caldji, Diorio, & Meaney, 2000;Champagne, 2008Champagne, , 2011Darnaudéry & Maccari, 2008;Franklin et al, 2012;Feng et al, 2011;Ros-Simó & Valverde, 2012). Assim, diferenças em cuidados maternais estão relacionadas com a saúde de seus fi lhos.…”