Stress Hormone Levels Research Articles

Fusarium Head Blight Infection Induced Responses of Six Winter Wheat Varieties in Ascorbate-Glutathione Pathway, Photosynthetic Efficiency and Stress Hormones.

Fusarium head blight (FHB) is one of the most studied fungal diseases of wheat, causing massive grain yield and quality losses. This study aimed to extend previous studies on the physiological and biochemical responses of winter wheat to FHB stress in a controlled environment by focusing on the ascorbate-glutathione pathway (AsA-GSH), photosynthetic efficiency, and stress hormone levels, thus providing insight into the possible interactions of different defense mechanisms during infection. The activity of AsA-GSH metabolism was increased in FHB resistant varieties, maintaining the redox state of spikes, and consequently preserving functional photosystem II. Furthermore, carotenoids (Car) were shown to be the major pigments in the photosystem assembly, as they decreased in FHB-stressed spikes of resistant and moderately resistant varieties, compared to controls. Car are also the substrate for the synthesis of abscisic acid (ABA), which acts as a fungal effector and its elevated content leads to increased FHB susceptibility in inoculated spikes. The results of this study contributed to the knowledge of FHB resistance mechanisms and can be used to improve the breeding of FHB resistant varieties, which is considered to be the most effective control measure.

Comparison of maternal versus postweaning ingestion of a high fat, high sucrose diet on depression-related behavior, novelty reactivity, and corticosterone levels in young, adult rat offspring

Consumption of a Western-type diet, high in fat and sugar, by mothers as well as maternal weight gain and obesity during gestation and lactation may impact offspring risk for mood and cognitive disorders. The objective of this study was to determine if ingestion of a high fat, high sucrose (HFS) diet by rat dams during gestation and lactation or by their pups after weaning impacted these behaviors and stress responsivity in young, adult offspring. To accomplish this, dams consumed either a 45% fat/high sucrose (HFS) diet or the AIN93G control diet during gestation and lactation. At weaning, pups from dams that consumed the HFS diet were weaned to the control diet. Pups from dams assigned to the control diet were weaned to either the control or HFS diet. Pup behavioral testing began at 10 weeks of age. Pups whose dams consumed the HFS diet during gestation and lactation exhibited increased depression-related behavior and baseline serum corticosterone levels, but no difference in peak levels in response to stress. Male pups of these dams displayed increased working memory during acquisition of the holeboard task and tended to exhibit more anxiety-related behavior in the elevated O-maze test. Regardless of when consumed, the HFS diet increased novelty reactivity in the open field test. These data indicate that diet but not maternal weight gain during gestation impacts offspring behavior and elevates stress hormone levels. Also, regardless of when consumed, the HFS diet increases novelty reactivity, a risk factor for depression and addiction.

Trait sensitivity to positive feedback is a predisposing factor for several aspects of compulsive alcohol drinking in male rats: behavioural, physiological, and molecular correlates

IntroductionAlcohol use disorder (AUD) is one of the most common psychiatric disorders and a leading cause of mortality worldwide. While the pathophysiology underlying AUD is relatively well known, the cognitive mechanisms of an individual’s susceptibility to the development of alcohol dependence remain poorly understood. In this study, we investigated the theoretical claim that sensitivity to positive feedback (PF), as a stable and enduring behavioural trait, can predict individual susceptibility to the acquisition and maintenance of alcohol-seeking behaviour in rats.MethodsTrait sensitivity to PF was assessed using a series of probabilistic reversal learning tests. The escalation of alcohol intake in rats was achieved by applying a mix of intermittent free access and instrumental paradigms of alcohol drinking. The next steps included testing the influence of sensitivity to PF on the acquisition of compulsive alcohol-seeking behaviour in the seeking-taking punishment task, measuring motivation to seek alcohol, and comparing the speed of extinction and reinstatement of alcohol-seeking after a period of abstinence between rats expressing trait insensitivity and sensitivity to PF. Finally, trait differences in the level of stress hormones and in the expression of genes and proteins in several brain regions of interest were measured to identify potential physiological and neuromolecular mechanisms of the observed interactions.ResultsWe showed that trait sensitivity to PF in rats determines the level of motivation to seek alcohol following the experience of its negative consequences. They also revealed significant differences between animals classified as insensitive and sensitive to PF in their propensity to reinstate alcohol-seeking behaviours after a period of forced abstinence. The abovementioned effects were accompanied by differences in blood levels of stress hormones and differences in the cortical and subcortical expression of genes and proteins related to dopaminergic, serotonergic, and GABAergic neurotransmission.ConclusionTrait sensitivity to PF can determine the trajectory of alcohol addiction in rats. This effect is, at least partially, mediated via distributed physiological and molecular changes within cortical and subcortical regions of the brain.

Stress hormone response to instrumented elective lumbar spine fusion surgery.

To understand the systemic effect of major spine surgery, we investigated stress, anabolic and catabolic hormonal levels and their association with interleukin 6 (IL-6) in patients undergoing elective lumbar spine fusion surgery. Blood samples were collected preoperatively, and at 1, 3, 42, 90days postoperatively (POD) from 49 patients who underwent elective lumbar spine fusion surgery. Serum concentration of cortisol was below the preoperative value at POD 1 but did not differ from the baseline values thereafter. Adrenocorticotropic hormone (ACTH) decreased at PODs 1 and 3. Testosterone decreased at PODs 1 and 3 in men, and at POD 3 in women. Sex hormone-binding globulin decreased at PODs 1 and 3 in both genders. No changes were observed in free testosterone or growth hormone concentrations. Insulin-like growth factor 1 increased significantly above the preoperative level at PODs 42 and 90 in women, and at POD 42 in men. IL-6 was significantly elevated at PODs 1 and 3. Increases in IL-6 from the preoperative level to POD 1 correlated significantly with decreases of cortisol at POD 1 but not with ACTH. There were only short-term stress hormonal changes after elective lumbar spine fusion surgery. Cortisol changes after elective lumbar spine surgery are transient and might be partly cytokine induced and non-ACTH driven since there was association between cortisol and IL-6 but not with ACTH and IL-6.

Effect of analgesia nociception index monitor-based nociception control on perioperative stress responses during laparoscopic surgery in Trendelenburg position: a randomized controlled trial.

The analgesia nociception index (ANI) monitor is a nociception monitoring device based on heart rate variability. We aimed to determine the effect of ANI monitor-based intraoperative nociception control on the perioperative stress response during laparoscopic surgery in the Trendelenburg position. Altogether, 72 female patients who underwent total laparoscopic hysterectomy were randomized to either the control or ANI group. Intraoperative nociception was controlled by remifentanil administration in a conventional manner (based on blood pressure and heart rate) in the control group and by ANI monitoring in the ANI group. Perioperative stress responses were estimated by measuring the levels of serum catecholamines and catabolic stress hormones at three timepoints: after loss of consciousness, at the end of surgery, and 1 h after the end of surgery. The serum cortisol level at the end of surgery was significantly higher in the ANI group than in the control group (p < 0.001), although more remifentanil was administered in the ANI group than in the control group (p < 0.001). Changes in the other estimators' levels were comparable between groups during the perioperative period. The hemodynamic profiles during surgery were also significantly different between the two groups. Phenylephrine use to treat hypotension was more common in the ANI group than in the control group (p = 0.005). However, postoperative clinical outcomes such as pain and nausea/vomiting did not differ between groups. ANI monitor-based nociception control in laparoscopic surgery in the Trendelenburg position did not improve perioperative stress responses, intraoperative opioid consumption, or postoperative clinical outcomes.Clinical trial registration: ClinicalTrials.gov (NCT04343638).

Aucubin improves chronic unpredictable mild stress-induced depressive behavior in mice via the GR/NF-κB/NLRP3 axis

Eucommia ulmoides Oliv (EUO) is a traditional therapeutic drug that tonifies the liver and kidney and may improve depression. However, the mechanism of action of the main component, aucubin (AU), is unknown. To study the therapeutic effect of AU, we constructed a chronic unpredictable mild stress (CUMS) depression model in mice. Depression-like behaviors, pathological damage, hormonal changes, inflammation, intranuclear expression of glucocorticoidreceptor (GR), and hippocampal protein expression were assessed. Immunofluorescence staining of the hippocampus showed that CUMS decreased neuronal regeneration, and axons were observed to be reduced and broken. Intracellular GR expression decreased in the hippocampus and hypothalamus, and serum levels of stress hormones increased. Furthermore, molecular changes indicative of pyroptosis were observed. AU administration reversed these changes and significantly improved the depression-like behavior induced by CUMS. Our results suggested that AU improves depression by promoting the intranuclear expression of GR and inhibiting nuclear factor-kappa B-mediated inflammatory activation-driven cell pyroptosis.

Zonulin levels are associated with cortisol, dopamine, and serotonin levels in irritable bowel syndrome

Increase intestinal permeability is one of the main mechanisms for the development of irritable bowel syndrome (IBS). The role of stress and nutrition factors is considered as key modifiable factors contributing to the development of increase intestinal permeability. Purpose of the study: to evaluate the content of a marker of increased intestinal permeability (zonulin in feces) in relation to dietary habits, levels of anxiety and depression, levels of stress hormones (cortisol in saliva) and neurotransmitters (serotonin in blood serum, dopamine in blood plasma) in patients with IBS. Materials and methods: an open cohort prospective study was conducted with the inclusion of 263 patients with an established diagnosis of IBS. The control group consisted of 40 healthy volunteers. All individuals included in the study were assessed for diet and eating habits, the severity of anxiety and depression, including the level of specific anxiety in relation to gastrointestinal symptoms, and quality of life. In addition, the levels of cortisol in the morning and evening portions of saliva, serum serotonin, plasma dopamine and fecal zonulin were assessed. Results: in patients with IBS, the marker of increased intestinal permeability (zonulin in feces) is closely related to the nature of nutrition, anxiety levels, cortisol and serotonin secretion, and is also associated with the development of abdominal pain, diarrhea, and the severity of the disease.

Bridging the mood and stress hormone levels between mothers and their babies: The study design and first preliminary results

The neurobiological mechanisms involved in the influence of post-partum maternal mood fluctuations on child development are far from being understood. Here we present the design of an ongoing study aimed to test the hypothesis that the mental state of the mother has an impact on her neonate which is manifested by similarities in the neuroendocrine function of the mother and the child. The hypothesis is being tested under both stress and non-stress conditions in mothers and babies aged 3–4 days and 7–9 months. The focus will be given to correlations with maternal postpartum mood. To confirm the correctness of methodological approaches and the feasibility of the study several preliminary analyses were performed. Salivary alpha-amylase activity as a marker of sympathetic activation and cortisol as the effective hormone of the hypothalamic-pituitary-adrenocortical axis were measured. The obtained results showed the feasibility of saliva sampling in neonates using a sampling time of 120 s. The analysis of cortisol in hair revealed increased concentrations during the third trimester of pregnancy, which is consistent with the knowledge of high cortisol concentrations during pregnancy. A positive correlation was observed between salivary cortisol values before and after the stress test in mother-infant dyads at both the post-partum period and 7–9 months thereafter. Understanding the mechanisms involved in “the bridge” between the mother and her baby will help to develop necessary interventions directed to help mothers in the early postpartum period.

Impact of host stress on the replication rate of Plasmodium: take it easy to avoid malaria recurrences

Malaria is widespread throughout the world and affects many animal species. Although the origin of this vector-borne disease was discovered more than a century ago, several aspects of the within-host infection dynamic are still poorly understood. Among them, the factors triggering parasite recurrences – episodes of brief increase in parasite number following a period when the parasite was either absent or present at very low levels in the blood – have still not been clearly identified. Yet, recurrences may contribute significantly to overall infection prevalence in vertebrate host populations. Here, we investigated whether artificial or natural increases in stress hormone levels in chronically infected birds influence the replication rate of Plasmodium relictum and transmission to its natural vector, the mosquito Culex pipiens. Our results provide evidence that increased levels of corticosterone, either induced by oral ingestion or caused by handling stress, can trigger malaria recurrences. However, we did not observe any effect on the transmission rate of the parasite to the mosquito vector. Our study is a first fundamental step in understanding the mechanisms underlying malaria recurrences. It remains to be ascertained whether this feature extends to other malaria system and in particular to human malaria.

The role of cortisol and microbiome in the anxiety of people with ASD and the use of ICTs for regulation

The role of hormones and microbiota in individuals with Autism Spectrum Disorder (ASD) has been an area of growing interest and research. Studies have shown that individuals with ASD have differences in their hormonal stress response and gut microbiota compared to typically developing individuals, which may contribute to their difficulties with emotional regulation, social communication, and cognitive flexibility. Research has found that individuals with ASD have higher levels of stress hormones, such as cortisol, which may interfere with mindfulness and attentional control. Additionally, individuals with ASD have been found to have altered gut microbiota, which may contribute to their difficulties with gastrointestinal symptoms and sensory processing. The link between hormones and microbiota in individuals with ASD is complex, and there is evidence to suggest that gut microbiota can influence the stress response and emotional regulation. Furthermore, there is emerging evidence to suggest that interventions targeting the gut microbiota, such as probiotics and prebiotics, may improve some of the behavioral and physiological symptoms associated with ASD. Overall, understanding the complex relationship between hormones and microbiota in individuals with ASD may provide new avenues for developing interventions to improve their overall health and well-being. Further research is needed to fully elucidate these relationships and develop effective interventions to improve the lives of individuals with ASD.

Stress and polycystic ovarian syndrome-a case control study among Indian women

BackgroundPolycystic ovarian syndrome (PCOS) is a common hormonal disorder that women belonging to premenopausal age group encounter. Due to its increasing incidence and burden of disease, re-searching the etiopathogenesis of this syndrome is essential and the need of the hour. Recently, the role of stress in the pathogenesis of the syndrome has come into the picture. Hence this study was done to find any significant difference in stress hormone levels between PCOS and healthy controls. MethodsA case-control study was conducted in SRIHER from 2019 to 2021 of which 250 participants were enrolled. Among the 250 subjects, 100 were diagnosed cases of polycystic ovarian syndrome and 150 were healthy women controls. Serum levels of DHEA and Cortisol were measured using ELISA technique and the data obtained was statistically analyzed to check for significance. ResultsThe serum levels of Cortisol and DHEA were found to be significantly elevated in PCOS compared to healthy women with a statistical significance of p = 0.001 and p = 0.01 respectively. The mean and standard deviation (SD) of Cortisol and DHEA among PCOS women were found to be 395.84 ± 195.62 and 6.04 ± 4.9 respectively. On the other hand, the mean and SD of Cortisol and DHEA among healthy controls were found to 256.26 ± 190.92 and 5.05 ± 3.20 correspondingly. ConclusionFrom this study, the stress hormone levels were found to be significantly distinct between the two groups. Stress could play a silent role in the pathogenesis of PCOS and its complications. Interventions to reduce stress among these women can considerably help to reduce the severity of existing symptoms as well as onset of dicey complications.

Aircraft noise and cardiovascular morbidity and mortality near Heathrow Airport: A case-crossover study

Aircraft noise causes annoyance and sleep disturbance and there is some evidence of associations between long-term exposures and cardiovascular disease (CVD). We investigated short-term associations between previous day aircraft noise and cardiovascular events in a population of 6.3 million residing near Heathrow Airport using a case-crossover design and exposure data for different times of day and night. We included all recorded hospitalisations (n = 442,442) and deaths (n = 49,443) in 2014–2018 due to CVD. Conditional logistic regression was used to estimate the ORs and adjusted for NO2 concentration, temperature, and holidays. We estimated an increase in risk for 10 dB increment in noise during the previous evening (Leve OR = 1.007, 95% CI 0.999–1.015), particularly from 22:00–23:00 h (OR = 1.007, 95% CI 1.000–1.013), and the early morning hours 04:30–06:00 h (OR = 1.012, 95% CI 1.002–1.021) for all CVD admissions, but no significant associations with day-time noise. There was effect modification by age-sex, ethnicity, deprivation, and season, and some suggestion that high noise variability at night was associated with higher risks. Our findings are consistent with proposed mechanisms for short-term impacts of aircraft noise at night on CVD from experimental studies, including sleep disturbance, increases in blood pressure and stress hormone levels and impaired endothelial function.

Noise Exposure and Stress Hormone Levels:A Review

Noise is one of the most common environmental hazards to which people are exposed,and the exposure to noise can cause not only hearing but also non-hearing damage.Although noise under safety limits may not affect the auditory system,it can cause changes in stress hormone levels,which is harmful to health.However,the current studies about the impact of noise on health mainly focus on the auditory system,and little is known about the relationship between noise and stress hormone levels.Therefore,this paper reviews the studies involving noise exposure and stress hormone levels,aiming to provide ideas for strengthening the prevention and control of noise hazards.

Effects of maternal social isolation on adult rodent offspring cognition

Prenatal experiences can influence offspring physiology and behaviour through the lifespan. Various forms of prenatal stress impair adult learning and memory function and can lead to increased occurrence of anxiety and depression. Clinical work suggests that prenatal stress and maternal depression lead to similar outcomes in children and adolescents, however the long-term effects of maternal depression are less established, particularly in well controlled animal models. Social isolation is common in depressed individuals and during the recent COVID-19 pandemic. Accordingly, for this study we were interested in the effects of maternal stress induced via social isolation on adult offspring cognitive functions including spatial, stimulus–response, and emotional learning and memory that are mediated by different networks centered on the hippocampus, dorsal striatum, and amygdala, respectively. Tasks included a discriminative contextual fear conditioning task and cue-place water task. Pregnant dams in the social isolation group were single housed prior to and throughout gestation. Once offspring reached adulthood the male offspring were trained on a contextual fear conditioning task in which rats were trained to associate one of two contexts with an aversive stimulus and the opposing context remained neutral. Afterwards a cue-place water task was performed during which they were required to navigate to both a visible and invisible platform. Fear conditioning results revealed that the adult offspring of socially isolated mothers, but not controls, were impaired in associating a specific context with a fear-inducing stimulus as assessed by conditioned freezing and avoidance. Results from the water task indicate that adult offspring of mothers that were socially isolated showed place learning deficits but not stimulus-response habit learning on the same task. These cognitive impairments, in the offspring of socially isolated dams, occurred in the absence of maternal elevated stress hormone levels, anxiety, or altered mothering. Some evidence suggested that maternal blood-glucose levels were altered particularly during gestation. Our results provide further support for the idea that learning and memory networks, centered on the amygdala and hippocampus are particularly susceptible to the negative impacts of maternal social isolation and these effects can occur without elevated glucocorticoid levels associated with other forms of prenatal stress.

Life in plastic, it's not fantastic: Sublethal effects of polyethylene microplastics ingestion throughout amphibian metamorphosis

Microplastics (MP) are an abundant, long-lasting, and widespread type of environmental pollution that is of increasing concern as it might pose a serious threat to ecosystems and species. However, these threats are still largely unknown for amphibians. Here, we used the African clawed frog (Xenopus laevis) as a model species to investigate whether polyethylene MP ingestion affects amphibian growth and development and leads to metabolic changes across two consecutive life stages (larvae and juveniles). Furthermore, we examined whether MP effects were more pronounced at higher rearing temperatures. Larval growth, development, and body condition were recorded, and standard metabolic rate (SMR) and levels of stress hormone (corticosterone, CORT) were measured. We determined variation in size, morphology, and hepatosomatic index in juveniles to identify any potential consequences of MP ingestion across metamorphosis. In both life stages, MP accumulation in the body was assessed. MP ingestion was found to result in sublethal effects on larval growth, development, and metabolism, to lead to allometric carry-over effects on juvenile morphology, and to accumulate in the specimens at both life stages. In larvae, SMR and developmental rate increased in response to MP ingestion; there additionally was a significant interaction of MP ingestion and temperature on development. CORT levels were higher in larvae that ingested MP, except at higher temperature. In juveniles, body was wider, and extremities were longer in animals exposed to MP during the larval stage; a high rearing temperature in combination with MP ingestion counteracted this effect. Our results provide first insights into the effects of MP on amphibians throughout metamorphosis and demonstrate that juvenile amphibians may act as a pathway for MP from freshwater to terrestrial environments. To allow for generalizations across amphibian species, future experiments need to consider the field prevalence and abundance of different MP in amphibians at various life stages.

Effects of stressogenic factors on the course of metabolic-associated fatty liver disease. Review

Metabolic‑associated fatty liver disease (MAFLD) is one of the most widespread diseases worldwide, including Ukraine. The complex pathophysiological MAFLD mechanisms include the disturbances of various processes (insulin resistance, lipotoxicity, pro‑inflammatory activation, changes in intestinal microbiota (IM), etc.). MAFLD is closely associated with the mental disorders, and they potentiate the course of each other. Stress induces both behavioral and biological reactions, which activate all the hypothalamic–pituitary–adrenal axis, thus resulting in the rise in the levels of cortisol and proinflammatory biomarkers that may be involved in the MAFLD development. There is a lack of data related to the effects of the stressogenic factors of the wartime and postwar state on the formation and progression of MAFLD. Knowledge about the role of chronic stress biomarkers (dehydroepiandrosterone, prolactin, brain neurotropic factor (BDNF)) in the MAFLD pathogenesis is insufficient. The literature data regarding changes in the qualitative and quantitative composition of the intestinal microbiota at the level of the main phyla in MAFLD patients are contradictory. The dynamics of intestinal microbiota under the influence of stress factors of war and post‑war times is not investigated. Complex determination of the degree of violation of the intestinal epithelial barrier integrity, the state of the IM, the level of stress hormones and pro‑inflammatory factors in patients with MAFLD in the stressful conditions of war and post‑war state will make it possible to clarify the pathophysiological links of MAFLD formation and progression and to work out pathogenetically based prophylactic and therapeutic interventions to inhibit the development of inflammation and fibrosis processes in liver tissue in MAFLD patients by means of correction of the microbiota and modification of the stress factors of the war and post‑war state. Moreover, it will enable investigations of the effects of the developed therapy on the clinical manifestations, metabolic profile, IM composition, inflammation, and the level of neurotropic hormones in MAFLD patients. Thus, scientific research of the effects of stressogenic factors on the course of metabolic‑associated fatty liver disease and determination of its pathogenetic mechanisms is relevant and appropriate.

Effects of Phytoncide Extracts on Antibacterial Activity, Immune Responses, and Stress in Dogs

Background and objective: Phytoncides are volatile and antibacterial organic compounds emitted by plants. In humans, these compounds are known to confer anti-bacterial, antioxidative, anti-inflammatory, immune-response-enhancing, and stress-reducing benefits. However, it remains largely unknown if phytoncides have parallel effects on dogs. Therefore, the aim of this study is to determine if phytoncides exhibit antibacterial activity, initiate an immune response, or alter stress hormone dynamics in dogs.Methods: Phytoncide extracts used in the study were obtained from Hinoki cypress (&lt;i&gt;Chamaecyparis obtuse&lt;/i&gt;) and Korean red pine (&lt;i&gt;Pinus densiflora&lt;/i&gt;). To examine the effectiveness of the extracts at initiating and sustaining anti-microbial activity in dogs, we conducted a disc diffusion experiment on bacteria that cause skin diseases in the dog. Furthermore, we evaluated the effects of phytoncides on the immune response and stress hormone levels of dogs by spraying the phytoncide extract on the skin of the beagle twice a day for eight weeks.Results: In this study, we investigated the effectiveness of phytoncides in eliminating bacteria cause skin infections in dogs. Our results confirm that mixed phytoncide extract was more effective than either phytoncide extract alone. After eight weeks, blood was collected from the common carotid artery of the beagle; we then measured the levels of immune response factors and cortisol. We found that with regards to the composition of white blood cells (WBCs), phytoncides significantly increased the proportion of lymphocytes and mononucleotides. They also increased the levels of immunoglobulin G and interferon-γ, while decreasing cortisol levels. Effects on several other immune markers were not significant.Conclusion: We suggest that mixed phytoncide extracts have antibacterial effects in dogs. Additionally, these compounds seem to enhance immunity and reduce stress in dogs.

Eating Habits, Anxiety and Depression in Patients with Irritable Bowel Syndrome: Clinical and Laboratory Comparisons

Aim: to assess the level of stress hormones (cortisol in saliva), neurotransmitters (serotonin in blood serum, dopamine in blood plasma) in relation to eating habits, anxiety and depression levels in patients with IBS.Materials and methods. An open cohort prospective study was conducted with the inclusion of 263 patients with an established diagnosis of IBS, among them 189 (71.9 %) women and 74 (28.1 %) men. The average age of patients with IBS was 29 [25; 35] years. The control group included 40 healthy volunteers. All individuals included in the study were assessed for diet and eating habits using the WHO CINDI program questionnaire, “Information on Nutrition and Eating Behavior”, the severity of anxiety and depression according to the HADS questionnaire, the level of specific anxiety in relation to gastrointestinal symptoms according to the VSI questionnaire, quality of life according to the IBS-QoL questionnaire. In addition, the enzyme immunoassay method was used to assess the levels of cortisol in the morning and evening portions of saliva, serotonin in the blood serum and dopamine in the blood plasma.Results. Among patients with IBS there is a statistically significantly higher level of cortisol in the morning and evening portions of saliva (U = 19.5, p &lt; 0.001 and U = 111.5, p &lt; 0.001, respectively), serotonin in blood serum (U = 269.0, p = 0.042) and lower plasma dopamine levels (U = 93.5, p = 0.0002) compared with controls. The mean salivary cortisol level among patients with IBS was 45.39 [29.86; 70.10] ng/ml in the morning and 19.21 [13.98; 23.50] ng/ml in the evening, while in the group of healthy individuals it was 19.0 [16.5; 21.7] and 9.7 [8.5; 10.5] ng/ml, respectively. The average content of serotonin in blood serum in patients with IBS was 188.78 [150.41; 230.32] ng/ml, among healthy individuals — 142.80 [130.52; 154.15] ng/ml. The average content of dopamine in blood plasma in patients with IBS was 28.83 [20.08; 41.54] ng/ml, in healthy individuals — 58.20 [48.15; 66.62] ng/ml.Conclusion. In patients with IBS the secretion of the stress hormone (cortisol) and neurotransmitters (serotonin, dopamine) is closely related to the nature of nutrition, the level of anxiety and depression, and is also associated with the clinical variant and severity of the course of the disease.

A single dose of hydrocortisone does not alter interhemispheric transfer of information or transcallosal integration.

Stress has been suggested as a factor that may explain the link between altered functional lateralization and psychopathology. Modulation of the function of the corpus callosum via stress hormones may be crucial in this regard. Interestingly, there is evidence that interhemispheric integration and hemispheric asymmetries are modifiable by endocrinological influences. In previous studies, our group could show an enhancing effect of acute stress on interhemispheric integration. To investigate if this effect can be attributed to an increase in the stress hormone cortisol, 50 male participants received 20 mg hydrocortisone or a placebo in a double-blind crossover design. In each test session, we collected EEG data while participants completed a lexical decision task and a Poffenberger paradigm. In the lexical decision task, we found shorter latencies of the N1 ERP component for contralateral compared to ipsilateral presentation of lexical stimuli. Similarly, we replicated the classical Poffenberger effect with shorter ERP latencies for stimuli presented in the contralateral visual field compared to the ipsilateral visual field. However, no effect of cortisol on latency differences between hemispheres could be detected. These results suggest that a temporary increase in cortisol alone might not be enough to affect the interhemispheric transfer of information via the corpus callosum. Together with previous results from our group, this suggests that chronically elevated stress hormone levels play a more central role in the relationship between altered hemispheric asymmetries and a variety of mental disorders.

Run access, hutch size and time-of-day affect welfare-relevant behaviour and faecal corticosterone in pair-housed pet rabbits

Although there exist several studies examining the housing needs of rabbits kept in laboratories and for meat, studies of the requirements of pet rabbits are few and focus entirely on single rabbits. Pet rabbits are recommended to be kept in pairs. We therefore conducted an experimental study to investigate the effects of common hutch sizes and access to an exercise area on the welfare of pairs of pet rabbits. Twenty pre-established pairs of adult neutered rabbits (one male, one female) were kept for eight weeks in standardised housing, Ten pairs were in small wooden hutches (0.73 m2) and ten in large (1.86 m2). An exercise area measuring 3×1 m was attached to each hutch and access was either unlimited or restricted to 3 h in the middle of the day. Each pair experienced each run access for three weeks in a counterbalanced design. We sampled behaviour at dawn, dusk and midday, and took faecal samples for corticosterone analysis at the end of each access treatment period. In a subsequent study, ten of the rabbit pairs were given 24 h access to the run, and their behaviour recorded. More overall time was spent in locomotion when run access was restricted to 3 h (F 1,17 =5.26, p = 0.035). Regardless of size of hutch, locomotory activity including play increased significantly when the pairs with restricted access were released into the run. This indicates a motivational rebound after behavioural restriction demonstrating the rabbits’ need to move within each 24 h cycle, as well as improved welfare There was a significant interaction between hutch size and run access on corticosterone levels; they were raised in the pairs kept in small hutches with restricted run access (F1,17 = 4.58, p = 0.047). The mid-day period was found to be their least active. Restricting rabbits’ opportunity to move and to get away from each other to times of day, when they would not naturally be as active, is likely to have contributed to the raised stress hormone levels in the pairs in the smaller hutches. Housing guidelines thus need to highlight the importance of allowing pet rabbits the freedom to exercise outside the mid-day period, even if they are kept in hutches larger than common practice. Hutches of commonly reported sizes of around 0.75 m2 floor area should not be recommended for rabbit pairs, even with access to an exercise area for three hours per day during the middle of the day.