Psychoneuroendocrinology
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Psychoneuroendocrinology · Sep 2009
Comparative StudyCirculating endocannabinoids and N-acyl ethanolamines are differentially regulated in major depression and following exposure to social stress.
Central endocannabinoid signaling is known to be responsive to stressful stimuli; however, there is no research to date characterizing the effects of stress on peripheral endocannabinoid content. The current study examined serum content of the endocannabinoid ligands N-arachidonylethanolamide (anandamide; AEA) and 2-arachidonoylglycerol (2-AG), and the non-cannabinoid N-acyl ethanolamine (NAE) molecules palmitoylethanolamide (PEA) and oleoylethanolamide (OEA) under basal conditions, immediately following the Trier Social Stress Test (TSST), and 30 min thereafter, in 15 medication-free women diagnosed with major depression, and 15 healthy matched controls. Basal serum concentrations of AEA and 2-AG, but not PEA or OEA, were significantly reduced in women with major depression relative to matched controls, indicating a deficit in peripheral endocannabinoid activity. ⋯ Serum concentrations of PEA and OEA were significantly lower than baseline 30 min following the cessation of the TSST. The magnitude of these responses did not differ between depressed and control subjects. These are the first data to demonstrate that the peripheral endocannabinoid/NAE system is responsive to exposure to stress.
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Psychoneuroendocrinology · Aug 2009
Neuroendocrine and psychometric evaluation of a placebo version of the 'Trier Social Stress Test'.
The "Trier Social Stress Test" (TSST) is one of the most prominent laboratory stress paradigms. It is often used to investigate the effects of stress on cognitive or affective parameters. Such studies need a non-stress control condition. ⋯ However, in this study we found similar reactions between TSST- and placebo-treated participants with regard to sAA-response. We suggest that the introduced placebo protocol for the TSST is a promising tool for future psychobiological research. The exact procedure for a given experiment should be tailored to the specific needs of the empirical question studied.
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Psychoneuroendocrinology · Jul 2009
Randomized Controlled TrialAssociation between arginine vasopressin 1a receptor (AVPR1a) promoter region polymorphisms and prepulse inhibition.
Arginine vasopressin and the arginine vasopressin 1a (AVPR1a) gene contribute to a range of social behaviors both in lower vertebrates and in humans. Human promoter-region microsatellite repeat regions (RS1 and RS3) in the AVPR1a gene region have been associated with autism spectrum disorders, prosocial behavior and social cognition. Prepulse inhibition (PPI) of the startle response to auditory stimuli is a largely autonomic response that resonates with social cognition in both animal models and humans. ⋯ Tests of within-subject effects (SPSS GLM) showed significant sexxRS3 interactions at 30 ms (p=0.045) and 60 ms (p=0.01). Longer alleles, especially in male subjects, are associated with significantly higher PPI response, consistent with a role for the promoter repeat region in partially molding social behavior in both animals and humans. This is the first report in humans demonstrating a role of the AVPR1a gene in contributing to the PPI response to auditory stimuli.
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Psychoneuroendocrinology · Jul 2009
Randomized Controlled TrialPassionate love and relationship thinkers: experimental evidence for acute cortisol elevations in women.
We assessed the impact of an individual difference variable, relationship-focused thinking, on women's acute salivary cortisol responses during and after a guided imagery task. Specifically, 29 healthy women, all of whom were experiencing high levels of passionate love, but varied on levels of relationship-focused thinking, were assigned to one of two experimental conditions: a partner reflection condition or a cross-sex friend reflection condition. ⋯ Our study significantly expands extant work on the passionate love-cortisol link by isolating the impact of a specific psychological variable, relationship-focused thinking, on the physiological experience of falling in love. We believe our work highlights the advances that can be made when established work in the close relationships and neuroendocrine fields are integrated.
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Psychoneuroendocrinology · Jul 2009
Developmental differences in infant salivary alpha-amylase and cortisol responses to stress.
This study examined developmental differences in infants' salivary alpha-amylase (sAA) and cortisol levels and responses to the well-baby exam/inoculation stress protocol at 2, 6, 12, and 24 months of age. Mother-infant pairs (n=85; 45 girls) were assessed during well-baby visits and saliva was sampled before the well-baby exam/inoculation procedure (pre-test) and at 5, 10, and 20 min post-inoculation stress. Older infants (24 months) had higher levels of sAA than younger infants (2, 6 and 12 months). ⋯ Mothers had higher sAA levels than their infants, but did not show sAA or cortisol increases to their infants' inoculation. Pre-test, maternal and infant sAA levels were positively correlated (rs .47 to .65) at 6, 12, and 24 months of age, but not at 2 months. These findings suggest that the association between the sympathetic branch of the autonomic nervous system and the secretion of sAA develops between 2 and 6 months of age, when levels of sAA are responsive to exposure to a painful stressor.