Psychoneuroendocrinology
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Psychoneuroendocrinology · Sep 2013
Comparative StudyDelays of 5-15 min between awakening and the start of saliva sampling matter in assessment of the cortisol awakening response.
Linking psychosocial measures to the cortisol awakening response (CAR) demands accurate saliva sampling times. Monitoring adherence to the saliva sampling protocol requires electronic monitoring of both awakening and sampling times since self-reported times are inaccurate. Delays greater than 15 min between awakening and commencement of saliva sampling reduce CAR magnitude. ⋯ The absence of this latent period in calculations leads to overestimation of the CAR magnitude on moderately non-adherent sampling days. These findings, if more universally generalizable, will further theoretical understanding of the physiology of the CAR, but are methodologically challenging for researchers since self-reported awakening times are not accurate enough to override the concerns raised. However accurate electronic measurement of adherence to protocol would enable sampling delays to be taken into account in computing CAR estimates.
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Psychoneuroendocrinology · Sep 2013
Developmental fluoxetine exposure and prenatal stress alter sexual differentiation of the brain and reproductive behavior in male rat offspring.
Depression during pregnancy and postpartum is a significant health problem and affects up to 20% of women. While selective serotonin reuptake inhibitor (SSRI) medications are the drug of choice for treatment of maternal depression, the combined effect of maternal depression and perinatal SSRI exposure on offspring development is poorly investigated. Our aim was to determine the role of exposure to fluoxetine during development on sexual behavior and sexually dimorphic brain structures in male offspring using a rodent model of maternal adversity. ⋯ Furthermore, developmental fluoxetine and/or prenatal stress decrease the area of the sexually dimorphic nucleus of the preoptic area (SDN-POA). Prenatal stress, but not exposure to developmental fluoxetine, decreases the number of tyrosine hydroxylase (TH)-positive cells in anteroventral periventricular nucleus (AVPv) and the volume of the posterior bed nucleus of the stria terminalis (pBST) in male offspring. These results provide important evidence for the long-term impact of maternal adversity and maternal fluoxetine use on the development of primary endocrinology systems in juvenile and adult male offspring.
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Psychoneuroendocrinology · Aug 2013
Analysis of baseline hypothalamic-pituitary-adrenal activity in late adolescence reveals gender specific sensitivity of the stress axis.
Dysfunctional regulation of the hypothalamic-pituitary-adrenal (HPA) axis has been proposed as an important biological mechanism underlying stress-related diseases; however, a better understanding of the interlinked neuroendocrine events driving the release of cortisol by this stress axis is essential for progress in preventing or halting irreversible development of adverse HPA-function. We aimed to investigate basal HPA-activity in a normal population in late adolescence, the time of life believed to overlap with HPA-axis maturation and establishment of a lasting set point level of HPA function. A total of 1258 participants (mean age 16.6 years) recruited from the Western Australian Pregnancy (Raine) Cohort provided fasting morning blood and saliva samples for basal HPA activity assessment. ⋯ Free plasma cortisol, calculated from total circulating cortisol and CBG concentrations, was also significantly reduced in girls using oral contraceptives, possibly via an enhancing effect of oral contraceptives on blood CBG content. This study highlights a clear gender difference in HPA activity under non-stressful natural conditions. This finding may be relevant for research into sex-specific stress-related diseases with a typical onset in late adolescence.
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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.