Differences in Salivary Alpha-Amylase and Cortisol Responsiveness following Exposure to Electrical Stimulation versus the Trier Social Stress Tests

Background

Cortisol is an essential hormone in the regulation of the stress response along the HPA axis, and salivary cortisol has been used as a measure of free circulating cortisol levels. Recently, salivary alpha-amylase (sAA) has also emerged as a novel biomarker for psychosocial stress responsiveness within the sympathetic adrenomedullary (SAM) system.

Principal Findings

We measured sAA and salivary cortisol in healthy volunteers after exposure to the Trier Social Stress Test (TSST) and electric stimulation stress. One hundred forty-nine healthy volunteers participated in this study. All subjects were exposed to both the TSST and electric stimulation stress on separate days. We measured sAA and salivary cortisol levels three times immediately before, immediately after, and 20 min after the stress challenge. The State (STAI-S) and Trait (STAI-T) versions of the Spielberger Anxiety Inventory test and the Profile of Mood State (POMS) tests were administered to participants before the electrical stimulation and TSST protocols. We also measured HF, LF and LF/HF Heart Rate Variability ratio immediately after electrical stimulation and TSST exposure. Following TSST exposure or electrical stimulation, sAA levels displayed a rapid increase and recovery, returning to baseline levels 20 min after the stress challenge. Salivary cortisol responses showed a delayed increase, which remained significantly elevated from baseline levels 20 min after the stress challenge. Analyses revealed no differences between men and women with regard to their sAA response to the challenges (TSST or electric stimulations), while we found significantly higher salivary cortisol responses to the TSST in females. We also found that younger subjects tended to display higher sAA activity. Salivary cortisol levels were significantly correlated with the strength of the applied electrical stimulation.

Conclusions

These preliminary results suggest that the HPA axis (but not the SAM system) may show differential response patterns to distinct kinds of stressors.     

The Resident-intruder Paradigm: A Standardized Test for Aggression,Violence and Social Stress

This video publication explains in detail the experimental protocol of the resident-intruder paradigm in rats. This test is a standardized method to measure offensive aggression and defensive behavior in a semi natural setting. The most important behavioral elements performed by the resident and the intruder are demonstrated in the video and illustrated using artistic drawings. The use of the resident intruder paradigm for acute and chronic social stress experiments is explained as well. Finally, some brief tests and criteria are presented to distinguish aggression from its more violent and pathological forms.     

The Delta-Sleep Inducing Peptide in Cerebral Mechanisms of Emotional Stress

The problem of the anti-stressor effect of the delta-sleep inducing peptide (DSIP) and of its neurophysiological mechanisms of action is considered. Physiological data are exposed that indicate an intraventricular administration of DSIP in rats to results in an increase of resistance to emotional stress, according to behavioral and autonomous reactions, and in a decrease of excitability of the brain structures responsible for protective reaction. Radioimmunological evidence is presented for the resistance of animals to emotional stress to depend on the content in hypothalamus of certain oligopeptides, such as -endorphin, DSIP, and the substance P. It was shown that animals resistant to emotional stress had a higher content of these oligopeptides in hypothalamus than those predisposed to stress. The issue is discussed that the prolonged anti-stressor effects after the DSIP administration are determined by considerable changes of the content of other polypeptides and hormones in hypothalamus and blood, which are involved in the reaction under the effect of DSIP.     

How Psychological Stress Affects Emotional Prosody

We explored how experimentally induced psychological stress affects the production and recognition of vocal emotions. In Study 1a, we demonstrate that sentences spoken by stressed speakers are judged by naïve listeners as sounding more stressed than sentences uttered by non-stressed speakers. In Study 1b, negative emotions produced by stressed speakers are generally less well recognized than the same emotions produced by non-stressed speakers. Multiple mediation analyses suggest this poorer recognition of negative stimuli was due to a mismatch between the variation of volume voiced by speakers and the range of volume expected by listeners. Together, this suggests that the stress level of the speaker affects judgments made by the receiver. In Study 2, we demonstrate that participants who were induced with a feeling of stress before carrying out an emotional prosody recognition task performed worse than non-stressed participants. Overall, findings suggest detrimental effects of induced stress on interpersonal sensitivity.     

The Impact of Psychological Stress on Men's Judgements of Female Body Size

Background

Previous work has suggested that the experience of psychological stress may influence physical attractiveness ideals, but most evidence in favour of this hypothesis remains archival. The objective of this study was to experimentally investigate the impact of stress on men''s judgements of female body size.

Methods

Men were randomly assigned to either an experimental group, in which they took part in a task that heightened stress (experimental group, n = 41) or in which they did not take part in such a task (control group, n = 40). Both groups rated the attractiveness of female bodies varying in size from emaciated to obese, completed a measure of appetite sensation, and had their body mass indices (BMIs) measured.

Results

Between-groups analyses showed that the experimental group was matched with the control group in terms of mean age, BMI, and appetite sensation. Further analyses showed that men in the experimental group rated a significantly heavier female body size as maximally attractive than the control group. Men in the experimental group also rated heavier female bodies as more attractive and idealised a wider range of female figures than did the control group.

Conclusion

This study found that the experience of stress was associated with a preference among men for heavier female body sizes. These results indicate that human attractiveness judgements are sensitive to variations in local ecologies and reflect adaptive strategies for dealing with changing environmental conditions.     

The Reaction to Social Stress in Social Phobia: Discordance between Physiological and Subjective Parameters

Background

Research on the biopsychological background of social phobia (SP) is scarce and inconsistent. We investigated endocrine and autonomic markers along with subjective responses to a standardized stress situation (Trier Social Stress Test, TSST) in SP patients and healthy controls (HC).

Methods

We examined 88 patients with the primary diagnosis of SP as well as 78 age and sex comparable HCs with the TSST. Blood and saliva samples were obtained before and after the TSST for the assessment of salivary cortisol, plasma cortisol, salivary alpha-amylase (sAA), and prolactin. Heart rate (HR) and heart rate variability (HRV) were recorded continuously. Scalp-near hair samples were collected for the assessment of long-term cortisol secretion. The self-reported stress response was measured with different state and trait scales.

Results

While self-reported anxiety was elevated in SP before, during, immediately after, and one week after the TSST, no significant differences in biological stress responses were observed between SP and HC. There was a trend for SP to show higher baseline stress markers. Also long-term cortisol deposition in hair remained unaltered.

Conclusions

Our results suggest that the excessive self-reported stress in SP is not reflected by a respective biological stress response. Patients with SP apparently show neither an extreme form of focused fear reactivity nor excessive defensive impairment.     

Zinc Accumulation Aggravates Cerebral Ischemia/Reperfusion Injury Through Inducing Endoplasmic Reticulum Stress

Neurochemical Research - Zinc is highly enriched in the central nervous system. Numerous evidences suggest that high concentration of zinc acts as a critical mediator of neuronal death in the...     

Chemosignals of Stress Influence Social Judgments

Human body odors have important communicative functions regarding genetic identity, immune fitness and general health, but an expanding body of research suggests they can also communicate information about an individual’s emotional state. In the current study, we tested whether axillary odors obtained from women experiencing psychosocial stress could negatively influence personality judgments of warmth and competence made about other women depicted in video scenarios. 44 female donors provided three types of sweat samples: untreated exercise sweat, untreated stress sweat and treated stress sweat. After a ‘washout’ period, a commercial unscented anti-perspirant product was applied to the left axilla only to evaluate whether ‘blocking’ the stress signal would improve the social evaluations. A separate group of male and female evaluators (n = 120) rated the women in the videos while smelling one of the three types of sweat samples. Women in the video scenes were rated as being more stressed by both men and women when smelling the untreated vs. treated stress sweat. For men only, the women in the videos were rated as less confident, trustworthy and competent when smelling both the untreated stress and exercise sweat in contrast to the treated stress sweat. Women’s social judgments were unaffected by sniffing the pads. The results have implications for influencing multiple types of professional and personal social interactions and impression management and extend our understanding of the social communicative function of body odors.     

Binge Ethanol and MDMA Combination Exacerbates Toxic Cardiac Effects by Inducing Cellular Stress

Binge drinking is a common pattern of ethanol consumption among young people. Binge drinkers are especially susceptible to brain damage when other substances are co-administered, in particular 3,4 methylendioxymethamphetamine (MDMA). The aim of the present work was to study the mechanisms implicated in the adaptive changes observed after administration of these drugs of abuse. So, we have evaluated the cardiac sympathetic activity and the expression and activation of heat shock protein 27 (HSP27), after voluntary binge ethanol consumption, alone and in combination with MDMA. Both parameters are markers of stressful situations and they could be modified inducing several alterations in different systems. Adolescent mice received MDMA, ethanol or both (ethanol plus MDMA). Drinking in the dark (DID) procedure was used as a model of binge. Noradrenaline (NA) turnover, tyrosine hydroxylase (TH), TH phosphorylated at serine 31 and HSP27 expression and its phosphorylation at serine 82 were evaluated in adolescent mice 48 h, 72 h, and 7 days after treatments in the left ventricle. NA and normetanephrine (NMN) were determined by high-performance liquid chromatography (HPLC); TH and HSP27 expression and phosphorylation were measured by quantitative blot immunollabeling using specific antibodies. Ethanol and MDMA co-administration increased NA turnover and TH expression and phosphorylation versus the consumption of each one of these drugs. In parallel with the described modifications in the cardiac sympathetic activity, our results showed that binge ethanol+MDMA exposure is associated with an increase in HSP27 expression and phosphorylation in the left ventricle, supporting the idea that the combination of both drugs exacerbates the cellular stress induced by ethanol or MDMA alone.     

Anxiety-Related Behaviours Associated with microRNA-206-3p and BDNF Expression in Pregnant Female Mice Following Psychological Social Stress

Stress during pregnancy can induce various psychological disorders in women. However, the association linking psychological stress during pregnancy with abnormal behaviours in females remains largely unknown. We employed a novel psychological stress model by introducing pregnant mice to witness the defeat process of their mated partner (WDPMP) and examined the effects of WDPMP on depression-/anxiety-like behaviours and on the expression of brain-derived neurotrophic factor (BDNF) and miR-206-3p in the hippocampus, medial prefrontal cortex (mPFC) and amygdala. Compared to pregnant control (PC) mice, pregnant stressed (PS) mice showed decreased sucrose preference during the late period of gestation, and after lactation, they spent less time in the open arms of the elevated plus maze and in the light chamber of the light/dark box. After lactation, decreased BDNF expression in both the hippocampus and mPFC of PS mice was found to be associated with enhanced miR-206-3p levels; meanwhile, elevated BDNF associated with decreased miR-206-3p expression was evident in the amygdala of the same PS mice. DNA methylation level in the Bdnf promoter did not show difference between PC and PS mice in the hippocampus. Transfection of miR-206-3p resulted in decreased BDNF levels in vitro. These results suggest that WDPMP stress during gestation can induce long-term mood alterations in pregnant mice, which may correlate with changes in miR-206-3p and BDNF expression in the hippocampus, mPFC and amygdala.     

The Cost Effectiveness of Psychological and Pharmacological Interventions for Social Anxiety Disorder: A Model-Based Economic Analysis

Background

Social anxiety disorder is one of the most persistent and common anxiety disorders. Individually delivered psychological therapies are the most effective treatment options for adults with social anxiety disorder, but they are associated with high intervention costs. Therefore, the objective of this study was to assess the relative cost effectiveness of a variety of psychological and pharmacological interventions for adults with social anxiety disorder.

Methods

A decision-analytic model was constructed to compare costs and quality adjusted life years (QALYs) of 28 interventions for social anxiety disorder from the perspective of the British National Health Service and personal social services. Efficacy data were derived from a systematic review and network meta-analysis. Other model input parameters were based on published literature and national sources, supplemented by expert opinion.

Results

Individual cognitive therapy was the most cost-effective intervention for adults with social anxiety disorder, followed by generic individual cognitive behavioural therapy (CBT), phenelzine and book-based self-help without support. Other drugs, group-based psychological interventions and other individually delivered psychological interventions were less cost-effective. Results were influenced by limited evidence suggesting superiority of psychological interventions over drugs in retaining long-term effects. The analysis did not take into account side effects of drugs.

Conclusion

Various forms of individually delivered CBT appear to be the most cost-effective options for the treatment of adults with social anxiety disorder. Consideration of side effects of drugs would only strengthen this conclusion, as it would improve even further the cost effectiveness of individually delivered CBT relative to phenelzine, which was the next most cost-effective option, due to the serious side effects associated with phenelzine. Further research needs to determine more accurately the long-term comparative benefits and harms of psychological and pharmacological interventions for social anxiety disorder and establish their relative cost effectiveness with greater certainty.     

Anthropological and Psychological Merge: Design of a Stress Measure for Mexican Farmworkers

This study implements qualitative and quantitative methodologies in the development of a culturally appropriate instrument of stress for Mexican immigrant farmworkers. Focus groups were used to uncover culturally based perspectives on life stressors, definitions of stress, and stress mediators. Qualitative data were analyzed using QSR NVivo and then used to develop a 23-item stress scale. The scale was tested for reliability and validity in an independent sample and demonstrates excellent reliability (α = 0.9123). Test-retest coefficients of the stress scale are also strong (r = 0.8344, p = 0.0000). Qualitative analyses indicated three major sources of stress: work, family, and community. Emotional aspects of stress also emerged, demonstrating a cultural perspective of stress closely related to feelings of despair and not being able to find a way out of despairing situations. This paper reveals themes gathered from the qualitative data and identifies reliability and validity constructs associated with the scale. The stress scale developed as part of this investigation is a reliable and culturally appropriate instrument for assessing stress among Mexican immigrant farmworkers.