Endocrine and Cognitive Adaptations to Cope with Stress in Immature Common Marmosets (Callithrix jacchus): Sex and Age Matter

Abstract

Phenotypic sex differences in primates are associated with body differentiation during the early stages of life, expressed in both physiological and behavioral features. Hormones seem to play a pivotal role in creating a range of responses to meet environmental and social demands, resulting in better reactions to cope with challenges to survival and reproduction. Steroid hormones actively participate in neuroplasticity and steroids from both gonads and neurons seem to be involved in behavioral modulation in primates. Indirect evidence suggests the participation of sexual steroids in dimorphism of the stress response in common marmosets. This species is an important experimental model in psychiatry, and we found a dual profile for cortisol in the transition from juvenile to subadult, with females showing higher levels. Immature males and females at 6 and 9 months of age moved alone from the family group to a new cage, over a 21-day period, expressed distinct patterns of cortisol variation with respect to range and duration of response. Additional evidence showed that at 12 months of age, males and females buffered the hypothalamic–pituitary–adrenal axis during chronic stress. Moreover, chronic stressed juvenile marmoset males showed better cognitive performance in working memory tests and motivation when compared to those submitted to short-term stress living in family groups. Thus, as cortisol profile seems to be sexually dimorphic before adulthood, age and sex are critical variables to consider in approaches that require immature marmosets in their experimental protocols. Moreover, available cognitive tests should be scrutinized to allow better investigation of cognitive traits in this species.

Common Marmosets: A Potential Translational Animal Model of Juvenile Depression

“…Afterward, males and females reduced their cortisol production in the two final phases of isolation (W7 and W8), again consistent with the results of IDS. For common marmosets at this age, de Sousa et al ( 40 ) found similar cortisol responses between male and female juveniles (12 months) after social isolation (21 days), in which they observed a drop in the cortisol response. Once again, probably, in DPT, autogrooming behavior acted as a decompensated allostatic mechanism responsible for the pathological reduction of cortisol, as both males and females showed an increase in the duration of autogrooming concomitant with decreased cortisol.…”

“…The common marmoset, C. jacchus , is a small and social non-human primate that adapts well to captivity and has a high fertility rate, when compared with Old World primates ( 35 – 37 ). This species exhibits a range of changes at the physiological and behavioral levels that resemble those observed in humans when facing stress ( 11 , 38 – 40 ). C. jacchus also display complex social organization and a number of similar social behaviors to humans and alloparental care ( 41 ), making this species relevant for the use as a model in several areas of research, including affective disorders such as anxiety and depression ( 42 , 43 ).…”

Long‐term treatment with the mTOR inhibitor rapamycin has minor effect on clinical laboratory markers in middle‐aged marmosets

“…Others have reported a lack of difference in body weight at least in young animals and (Araujo et al, 2000) and marmosets generally described as monomorphic (Tardif, Power, Ross, & Rutherford, 2013). However, there have also been numerous reports of sex-specific phenotypes including behavior (Yamamoto, Domeniconi, & Box, 2004), endocrine beyond the basic sex hormones (de Sousa, Galvao, Sales, de Castro, & Galvao-Coelho, 2015), and even at the molecular level in terms of gene expression differences (Reinius et al, 2008). Hematological differences have been reported between male and female marmosets though in relatively young animals (Silva et al, 2014).…”

Physiological and behavioral responses to routine procedures in captive common marmosets (Callithrix jacchus)

“…Indeed, singlehoused female Cynomolgus monkeys are more behaviorally reactive to small transport cages than pair-housed females (Schapiro et al 2012). For common marmosets, a number of studies have shown that this species exhibits different endocrine and behavioral responses depending on the nature of the stressor, sex, baseline cortisol, and age (Galvão-Coelho et al 2008, Sousa et al 2015.…”