Psychoneuroendocrinology
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Psychoneuroendocrinology · Jun 2013
Importance of epigenetic mechanisms in visceral pain induced by chronic water avoidance stress.
Epigenetic molecular mechanisms, which include DNA methylation and histone deacetylation, are implicated in the dysregulation of the hypothalamic-pituitary-adrenal (HPA) axis. Previously, we demonstrated that repeated water avoidance stress (WAS), a validated model of chronic psychological stress, induces heightened visceral pain behaviors in rodents that resemble irritable bowel syndrome (IBS) sequelae. However, the involvement of epigenetic molecular mechanisms in the pathophysiology of stress-induced visceral pain has not been explored. ⋯ Compared to SHAM controls, methylation of the GR gene was increased following WAS while expression of the GR gene was decreased. Methylation of the CRF promoter was decreased with WAS with a concomitant increase in CRF expression. This study demonstrates the involvement of central epigenetic mechanisms in regulating stress-induced visceral hypersensitivity and provides a foundation for exploring the epigenetic mechanisms that may contribute to IBS-like symptomatology.
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Psychoneuroendocrinology · May 2013
Randomized Controlled TrialChronicity of depressive problems and the cortisol response to psychosocial stress in adolescents: the TRAILS study.
Clinical and epidemiological studies, further supported by meta-analytic studies, indicate a possible association between chronicity (i.e., persistence or recurrence) of depression and hypothalamic-pituitary-adrenal (HPA) axis responsiveness to psychosocial stress. In the present study, we examined whether and how chronicity of depressive problems predicts cortisol responses to a standardized social stress test in adolescents. Data were collected in a high-risk focus sample (n=351) of the Tracking Adolescents' Individual Lives Survey (TRAILS) cohort, a large prospective population study with bi- to triennial measurements. ⋯ Chronicity of depressive problems was significantly associated with cortisol stress responses. The relationship was curvilinear, with recent-onset depressive problems predicting an increased cortisol response, and more chronic depressive problems a blunted response. The results of this study suggest that depressive problems initially increase cortisol responses to stress, but that this pattern reverses when depressive problems persist over prolonged periods of time.
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Psychoneuroendocrinology · Apr 2013
Influences of early shift work on the diurnal cortisol rhythm, mood and sleep: within-subject variation in male airline pilots.
We aimed to investigate how early and late work shifts influenced the diurnal cortisol rhythm using a within-subjects study design. Participants were 30 healthy male non-smoking pilots, mean age 39.4, employed by a short-haul airline. The standard rotating shift pattern consisted of 5 early shifts (starting before 0600 h), followed by 3 rest days, 5 late shifts (starting after 1200 h) and 4 rest days. ⋯ Early shifts were also associated with shorter sleep duration but co-varying for sleep duration did not alter the effects of shift on the cortisol rhythm. Both types of work shift were associated with more stress, tiredness and lower happiness than rest days, but statistical adjustment for mood ratings did not alter the findings. Early shift days were associated with significantly higher levels of circulating cortisol during waking hours than late shifts or rest days.
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Psychoneuroendocrinology · Jan 2013
ReviewGlucocorticoid excess and the developmental origins of disease: two decades of testing the hypothesis--2012 Curt Richter Award Winner.
Low birthweight, a marker of an adverse in utero environment, is associated with cardiometabolic disease and brain disorders in adulthood. The adaptive changes made by the fetus in response to the intra-uterine environment result in permanent changes in physiology, structure and metabolism, a phenomenon termed early life programming. One of the key hypotheses to explain programming, namely over exposure of the developing fetus to glucocorticoids, was proposed nearly two decades ago, following the observation that the fetus was protected from high glucocorticoid levels in the mother by the actions of the placental barrier enzyme, 11β-hydroxysteroid dehydrogenase, which converts active glucocorticoids into inactive products. ⋯ In a recent study we showed that alterations in DNA methylation at genes important in regulating cortisol levels, tissue glucocorticoid action, blood pressure and fetal growth, are present in adulthood in association with both early life parameters and cardiometabolic risk factors. These preliminary data add to the limited literature in humans indicating a persisting epigenetic link between early life events and subsequent disease risk. Such findings open novel avenues for further exploration of the contribution of glucocorticoids to later life disease.
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Psychoneuroendocrinology · Jan 2013
Comparative Study Controlled Clinical TrialSympathetic activity and hypothalamo-pituitary-adrenal axis activity during sleep in post-traumatic stress disorder: a study assessing polysomnography with simultaneous blood sampling.
Nightmares and insomnia in PTSD are hallmark symptoms, yet poorly understood in comparison to the advances toward a biological framework for the disorder. According to polysomnography (PSG), only minor changes in sleep architecture were described. This warrants alternative methods for assessing sleep regulation in PTSD. ⋯ This study suggests that hypothalamo-pituitary-adrenal (HPA) axis activity is related to sleep fragmentation in PTSD. Also, activity of the sympathetic nervous system (SNS) is increased during sleep in PTSD. Further research is necessary to explore the potential causal relationship between sleep problems and the activity of the HPA-axis and SNS in PTSD.