Psychoneuroendocrinology
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Psychoneuroendocrinology · Dec 2015
Activation of the kynurenine pathway is associated with striatal volume in major depressive disorder.
Inflammation, which may be present in a subgroup of individuals with major depressive disorder (MDD), activates the kynurenine metabolic pathway to produce kynurenine metabolites kynurenic acid (KynA) and quinolinic acid (QA). We have previously reported an association between the ratio of KynA to QA and hippocampal volume in MDD. In animals, inflammation leads to deficits in incentive motivation. ⋯ Further, striatal volume was correlated with the items, "concentration difficulties", "lassitude", and "pessimism" from the Montgomery-Asberg Depression Rating Scale. Our results raise the possibility that activation of the kynurenine pathway is a marker of an inflammatory process that leads to reductions in striatal volume. However, unlike the hippocampus, the association does not appear to be mediated by the relative balance between KynA and QA.
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Psychoneuroendocrinology · Dec 2015
Prenatal stress programs neuroendocrine stress responses and affective behaviors in second generation rats in a sex-dependent manner.
An adverse environment in early life is often associated with dysregulation of the hypothalamo-pituitary-adrenal (HPA) axis and higher rates of mood disorders in adulthood. In rats, exposure to social stress during pregnancy results in hyperactive HPA axis responses to stress in the adult offspring and heightened anxiety behavior in the males, but not the females. Here we tested whether, without further intervention, the effects of prenatal stress (PNS) in the first filial generation (F1) are transmitted to the F2 generation via the maternal line. ⋯ No differences in depressive-like behavior (sucrose preference or forced swim test) were observed in either sex. In conclusion, the effects of maternal stress during pregnancy on HPA axis regulation and anxiety-like behavior can be transmitted to future generations in a sex-dependent manner. These data have implications for human neuropsychiatric disorders with developmental origins.
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Psychoneuroendocrinology · Dec 2015
Development of the cortisol circadian rhythm in the light of stress early in life.
The secretion of the stress hormone cortisol follows a diurnal circadian rhythm. There are indications that this rhythm is affected by stress early in life. This paper addresses the development of the cortisol circadian rhythm between 1 and 6 years of age, and the role of maternal stress and anxiety early in the child's life on this (developing) rhythm. ⋯ Higher levels of early postnatal maternal anxiety were associated with flatter cortisol declines in children. Higher levels of early postnatal maternal daily hassles were associated with steeper child cortisol declines over the day. These results indicated developmental change in children's cortisol secretion from 1 to 6 years and associations between maternal stress and anxiety early in children's lives and children's cortisol circadian rhythm in early childhood.
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Psychoneuroendocrinology · Oct 2015
Anesthesia with sevoflurane in neonatal rats: Developmental neuroendocrine abnormalities and alleviating effects of the corticosteroid and Cl(-) importer antagonists.
1.5 million children under 12 months of age are exposed to general anesthesia annually in the United States alone. Human and especially animal studies provide evidence that exposure to general anesthesia during the early postnatal period may lead to long-term neurocognitive abnormalities via poorly understood mechanisms. We investigated whether an immature stress response system and γ-aminobutyric acid (GABA) type A receptor activities are involved in mediating these abnormalities. ⋯ Sevoflurane-enhanced neuronal excitation and elevated corticosteroid levels at the time of anesthesia contribute to the mechanisms initiating neonatal sevoflurane-induced long-term endocrine and neurobehavioral abnormalities.
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Psychoneuroendocrinology · Oct 2015
The cortisol awakening response (CAR) in toddlers: Nap-dependent effects on the diurnal secretory pattern.
Cortisol levels in adults show a sharp decrease from mid-morning to mid-afternoon. Most toddlers take afternoon naps, which is associated with a less mature diurnal pattern characterized by a midday plateau in cortisol secretion. Napping in preschoolers produces a robust cortisol awakening response (CAR), which may account for such maturational differences. This experimental study extends prior work by examining whether the presence and timing of the nap-dependent CAR influences the diurnal cortisol pattern in toddlers. ⋯ These well-controlled findings suggest that the presence and timing of daytime naps influence the pattern of diurnal cortisol secretion in toddlers. They also provide support for the hypothesis that napping is the primary state driving the immature midday plateau in cortisol secretion, which becomes more adult-like across childhood. Prior studies of the diurnal cortisol pattern have employed a cubic model, and therefore, have not detected all possible variations due to napping. Our experimental data have important methodological implications for researchers examining associations between the slope of the diurnal cortisol pattern and developmental outcomes, as well as those utilizing afternoon cortisol reactivity protocols in napping children.