Environmental stress alters genetic regulation of novelty seeking in vervet monkeys.

Considerable attention has been paid to identifying genetic influences and gene-environment interactions that increase vulnerability to environmental stressors, with promising but inconsistent results. A nonhuman primate model is presented here that allows assessment of genetic influences in response to a stressful life event for a behavioural trait with relevance for psychopathology. Genetic and environmental influences on free-choice novelty seeking behaviour were assessed in a pedigreed colony of vervet monkeys before and after relocation from a low stress to a higher stress environment. Heritability of novelty seeking scores, and genetic correlations within and between environments were conducted using variance components analysis. The results showed that novelty seeking was markedly inhibited in the higher stress environment, with effects persisting across a 2-year period for adults but not for juveniles. There were significant genetic contributions to novelty seeking scores in each year (h(2) = 0.35-0.43), with high genetic correlations within each environment (rhoG > 0.80) and a lower genetic correlation (rhoG = 0.35, non-significant) between environments. There were also significant genetic contributions to individual change scores from before to after the move (h(2) = 0.48). These results indicate that genetic regulation of novelty seeking was modified by the level of environmental stress, and they support a role for gene-environment interactions in a behavioural trait with relevance for mental health

Common marmoset (Callithrix jacchus) personality, subjective well-being, hair cortisol level and AVPR1a, OPRM1, and DAT genotypes

We studied personality, subjective well-being, and hair cortisol level, in common marmosets Callithrix jacchus, a small, cooperatively breeding New World monkey, by examining their associations with one another and genotypes. Subjects were 68 males and 9 females that lived in the RIKEN Center for Life Science Technologies. Personality and subjective well-being were assessed by keeper ratings on two questionnaires, hair samples were obtained to assay cortisol level and buccal swabs were used to assess AVPR1a, OPRM1 and DAT genotypes. Three personality domains—Dominance, Sociability, and Neuroticism—were identified. Consistent with findings in other species, Sociability and Neuroticism were related to higher and lower subjective well-being, respectively. Sociability was also associated with higher hair cortisol levels. The personality domains and hair cortisol levels were heritable and associated with genotypes: the short form of AVPR1a was associated with lower Neuroticism and the AA genotype of the A111T SNP of OPRM1 was related to lower Dominance, lower Neuroticism, and higher hair cortisol level. Some genetic associations were not in directions that one would expect given findings in other species. These findings provide insights into the proximate and ultimate bases of personality in common marmosets, other primates and humans

Environmental stress alters genetic regulation of novelty seeking in vervet monkeys.

Considerable attention has been paid to identifying genetic influences and gene-environment interactions that increase vulnerability to environmental stressors, with promising but inconsistent results. A nonhuman primate model is presented here that allows assessment of genetic influences in response to a stressful life event for a behavioural trait with relevance for psychopathology. Genetic and environmental influences on free-choice novelty seeking behaviour were assessed in a pedigreed colony of vervet monkeys before and after relocation from a low stress to a higher stress environment. Heritability of novelty seeking scores, and genetic correlations within and between environments were conducted using variance components analysis. The results showed that novelty seeking was markedly inhibited in the higher stress environment, with effects persisting across a 2-year period for adults but not for juveniles. There were significant genetic contributions to novelty seeking scores in each year (h(2) = 0.35-0.43), with high genetic correlations within each environment (rhoG > 0.80) and a lower genetic correlation (rhoG = 0.35, non-significant) between environments. There were also significant genetic contributions to individual change scores from before to after the move (h(2) = 0.48). These results indicate that genetic regulation of novelty seeking was modified by the level of environmental stress, and they support a role for gene-environment interactions in a behavioural trait with relevance for mental health

Possible Contribution of PTSD to Altered Cortisol Activity in Young Adult Obese African-American Women

OBJECTIVE: African-Americans have been found to experience increased rates of post-traumatic stress disorder (PTSD), obesity, and flatter diurnal cortisol slopes compared to other demographic groups. Further exploration, however, is needed to understand how PTSD impacts diurnal cortisol activity in obese African-American women. The purpose of the current study is to examine the relationship between salivary cortisol levels and PTSD in a sample of obese young adult African-American women and to examine how depression and insomnia influence the relationship. METHODS: Thirty-four young adult African-American women (mean age=24.0 years; mean BMI=37.4 kg/m(2), 6/34 of the sample had a score of 40 or above on the PTSD Checklist (PCL) representing clinically significant PTSD) filled out questionnaires assessing PTSD, lifetime exposure to traumatic events, insomnia severity, and depression. A home-based assessment of salivary cortisol was provided upon awakening at 30 min and 1, 3, 6, and 12 h. RESULTS: There was a significant interaction between PTSD status and diurnal cortisol activity (p<0.04). There were trends for higher cortisol levels at awakening (p<0.051) and 30 min post-awakening (p<0.059) with PTSD. The significance of the interaction between PTSD and cortisol was attenuated by co-varying for depression and insomnia (p>0.05). CONCLUSION: PTSD, influenced by depression and insomnia symptoms, has an impact on diurnal cortisol activity in obese young adult African-American women