Psychoneuroendocrinology
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Psychoneuroendocrinology · Jul 2013
The use of saliva for assessment of cortisol pulsatile secretion by deconvolution analysis.
Cortisol is the key effector molecule of the HPA axis and is secreted in a pulsatile manner in all species studied. In order to understand cortisol signalling in health and disease, detailed analysis of hormone pulsatility is necessary. To dissect cortisol pulsatility in plasma deconvolution techniques have been applied. ⋯ The deconvolution of the most distinct component of cortisol diurnal rhythm-cortisol awakening response (CAR), revealed an average 2.5±1.1 peaks based on the individual time for cortisol to return to baseline levels. In conclusion, deconvolution analysis of plasma and salivary cortisol concentration time series showed a close correlation and similar pulsatile characteristics between saliva and plasma cortisol. Similarly, Monte Carlo simulations revealed a high concordance between the peaks in these coupled time series suggesting that saliva is a suitable medium for subsequent deconvolution analysis yielding accurate and reliable models of cortisol secretion in particular during the morning hours.
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Psychoneuroendocrinology · Jul 2013
Influence of stress on fear memory processes in an aversive differential conditioning paradigm in humans.
It is widely assumed that learning and memory processes play an important role in the pathogenesis, expression, maintenance and therapy of anxiety disorders, such as phobias or post-traumatic stress disorder (PTSD). Memory retrieval is involved in symptom expression and maintenance of these disorders, while memory extinction is believed to be the underlying mechanism of behavioral exposure therapy of anxiety disorders. There is abundant evidence that stress and stress hormones can reduce memory retrieval of emotional information, whereas they enhance memory consolidation of extinction training. ⋯ No group differences were observed with respect to extinction. In conclusion, the present study provides evidence that stress can reduce memory retrieval of conditioned fear in men. Our findings may contribute to the understanding of the effects of stress and glucocorticoids on fear symptoms in anxiety disorders and suggest that such effects may be sex-specific.
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Psychoneuroendocrinology · Jul 2013
Pubertal immune challenge blocks the ability of estradiol to enhance performance on cognitive tasks in adult female mice.
Puberty is a period characterized by brain reorganization that contributes to the development of neural and behavioral responses to gonadal steroids. Previously, we have shown that a single injection of the bacterial endotoxin, lipopolysaccharide (LPS; 1.5mg/kg IP), during the pubertal period (around 6weeks old) in mice decreases sexual receptivity in response to estradiol and progesterone in adulthood. These findings suggest that pubertal immune challenge has an enduring effect of decreasing the behavioral responsiveness to gonadal steroid hormones. ⋯ In contrast, in females treated with LPS at 6weeks old, estradiol failed to improve social and object memories. These results support the hypothesis that exposure to an immune challenge during puberty reduces at least some of the cognitive effects of estradiol. Moreover, these results support the idea that pubertal immune challenge compromises a wide variety of behavioral influences of ovarian hormones.
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Psychoneuroendocrinology · Jul 2013
Thyroid function tests at delivery and risk for postpartum depressive symptoms.
Postpartum depression (PPD) is a common childbirth complication, which can have negative effects on both the newly delivered woman and her family. This condition is underdiagnosed and inadequately treated, while a biological diagnostic test is not yet available. Furthermore, postpartum thyroid dysfunction is common among new mothers, and some evidence point to an association between PPD and thyroid function disturbances. ⋯ Using a binary logistic regression model (adjusting for previous psychiatric contact, smoking during pregnancy, pre-pregnancy body mass index (BMI) and sleep), having a thyroid stimulating hormone (TSH) level over the clinical cut-off level of 4.0 mU/L was associated with increased risk for depressive symptoms at six months postpartum (OR 11.30, 95% CI 1.93-66.11). A ROC analysis revealed that the predictive variable (PV) had significant predictive ability for PPD at 6 months postpartum, given that the AUC was 0.764, and at a PV cut-off value of 6.33, the sensitivity and specificity were 76.2% and 69.4%, respectively. If these findings are replicated in future studies, they can have important clinical implications, since TSH determination is an inexpensive routine blood test, and its inclusion in a biological screening test for PPD involving other parameters would be tempting.