Cortisol Release Research Articles

Coptidis Rhizoma Prevents Heat Stress-Induced Brain Damage and Cognitive Impairment in Mice.

Heat stress conditions lead to neuroinflammation, neuronal death, and memory loss in animals. Coptidis Rhizoma (CR) exhibits potent fever-reducing effects and has been used as an important traditional medicinal herb for treating fever. However, to date, the effects of antipyretic CR on heat-induced brain damages have not been investigated. In this study, CR significantly reduced the elevation of ear and rectal temperatures after exposure to heat in mice. Additionally, CR attenuated hyperthermia-induced stress responses, such as release of cortisol into the blood, and upregulation of heat shock protein and c-Fos in the hypothalamus and hippocampus of mice. The administration of CR inhibited gliosis and neuronal loss induced by thermal stress in the hippocampal CA3 region. Treatment with CR also reduced the heat stress-induced expression of nuclear factor kappa β, tumor necrosis factor-α, and interleukin-1β (IL-1β) in the hippocampus. Moreover, CR significantly decreased proinflammatory mediators such as IL-9 and IL-13 in the heat-stressed hypothalamus. Furthermore, CR attenuated cognitive dysfunction triggered by thermal stress. These results indicate that CR protects the brain against heat stress-mediated brain damage via amelioration of hyperthermia and neuroinflammation in mice, suggesting that fever-reducing CR can attenuate thermal stress-induced neuropathology.

The brain-gut axis of fish: Rainbow trout with low and high cortisol response show innate differences in intestinal integrity and brain gene expression

In fish, the stress hormone cortisol is released through the action of the hypothalamic pituitary interrenal axis (HPI-axis). The reactivity of this axis differs between individuals and previous studies have linked this to different behavioural characteristics and stress coping styles. In the current study, low and high responding (LR and HR) rainbow trout in terms of cortisol release during stress were identified, using a repeated confinements stress test. The expression of stress related genes in the forebrain and the integrity of the stress sensitive primary barrier of the intestine was examined. The HR trout displayed higher expression levels of mineralocorticoid and serotonergic receptors and serotonergic re-uptake pumps in the telencephalon during both basal and stressed conditions. This confirms that HPI-axis reactivity is linked also to other neuronal behavioural modulators, as both the serotonergic and the corticoid system in the telencephalon are involved in behavioural reactivity and cognitive processes. Involvement of the HPI-axis in the brain-gut-axis was also found. LR trout displayed a lower integrity in the primary barrier of the intestine during basal conditions compared to the HR trout. However, following stress exposure, LR trout showed an unexpected increase in intestinal integrity whereas the HR trout instead suffered a reduction. This could make the LR individuals more susceptible to pathogens during basal conditions where instead HR individuals would be more vulnerable during stressed conditions. We hypothesize that these barrier differences are caused by regulation/effects on tight junction proteins possibly controlled by secondary effects of cortisol on the intestinal immune barrier or differences in parasympathetic reactivity.

ACUTE CARDIOVASCULAR RESPONSE TO PRE-PRANDIAL AND POSTPRANDIAL EXERCISE IN ACTIVE MEN

ABSTRACT Introduction: Pre-prandial exercise promotes greater mobilization of fat metabolism due to the increased release of catecholamines, cortisol, and glucagon. However, this response affects how the cardiovascular system responds to exercise. Objective: To evaluate the response of systolic, diastolic, and mean blood pressure, heart rate (HR) and rate-pressure product (RPP) to pre- and postprandial exercise. Methods: Ten physically active male subjects (25.50 ± 2.22 years) underwent two treadmill protocols (pre- and postprandial) performed for 36 minutes at 65% of VO2max on different days. On both days, subjects attended the laboratory on a 10-hour fasting state. For the postprandial session, volunteers ingested a pre-exercise meal of 349.17 kcal containing 59.3 g of carbohydrates (76.73%), 9.97 g of protein (12.90%), and 8.01 g of lipids (10.37%). Blood pressure, HR and RPP were measured before and after exercise. The 2x2 factorial Anova with the multiple comparisons test of Bonferroni was applied to analyze cardiovascular variables in both moments (pre- vs. postprandial). The significance level was set at p<0.05. Results: Systolic (121.70 ± 7.80 vs. 139.78 ± 12.91 mmHg) and diastolic blood pressure (66.40 ± 9.81 vs. 80.22 ± 8.68 mmHg) increased significantly after exercise only in the postprandial session (p<0.05). HR increased significantly (p<0.05) after both protocols (64.20 ± 15.87 vs. 141.20 ± 10.33 bpm pre-prandial and 63.60 ± 8.82 vs. 139.20 ± 10.82 bpm postprandial). RPP had a similar result (8052.10 ± 1790.68 vs. 18382.60 ± 2341.66 mmHg.bpm in the pre-prandial session and 7772.60 ± 1413.76 vs. 19564.60 ± 3128.99 mmHg.bpm in the postprandial session). Conclusion: These data suggest that fasted exercise does not significantly alter the blood pressure. Furthermore, the meal provided before the postprandial exercise may promote a greater blood pressure responsiveness during exercise.

The cortisol:C-reactive protein ratio and negative affect reactivity in depressed adults.

We evaluated the effect of the cortisol (CORT) to high sensitivity C-reactive protein (hsCRP) ratio on stress-induced negative affect (NA) reactivity and whether the association was moderated by depressive symptom severity and gender. The CORT/CRP ratio was used to evaluate the integrity of the negative feedback loop between the hypothalamic-pituitary-adrenal axis and inflammatory response system. Basal CORT and hsCRP levels were measured in fasting blood samples from 198 medication-free and nonsmoking healthy men and women. Depressive symptom severity was assessed using the Hamilton Rating Scale for Depression (HAMD). NA ratings were collected at baseline and at the completion of the laboratory stressors, the Anger Recall Interview (ARI) and reading. Adjusting for potential confounders and baseline NA, analysis revealed a significant relationship between CORT/CRP ratio and NA reactivity to ARI as a function of depressive symptom severity. Simple effects revealed that for participants with high HAMD, decreasing CORT/CRP ratio, suggestive of an insufficient CORT release relative to higher hsCRP, predicted increasing stress-induced NA reactivity. For participants with low HAMD, the CORT/CRP ratio failed to predict NA reactivity. Gender did not moderate the joint effect of depressive symptom severity and the CORT/CRP ratio on stress-induced NA reactivity. This is the first study to document that a premorbid dysregulation of the neuro-immune relationship, characterized by an insufficient release of CORT in conjunction with higher CRP, plays a role in stress sensitivity, and specifically NA reactivity, in individuals with elevated levels of depression symptoms. (PsycINFO Database Record

Cortisol stress resonance in the laboratory is associated with inter-couple diurnal cortisol covariation in daily life

In laboratory environments individuals may display empathic cortisol stress responses merely from observing another experience psychosocial stress. Moreover, within couples, women synchronize their own to their partners' stress-induced cortisol release. We investigated whether a woman's tendency to experience such cortisol stress resonance in a controlled laboratory task is associated with the degree to which her and her partner's diurnal cortisol levels covary in a naturalistic environment. Such habitual cortisol covariation may be a pathway via which close relationships influence health outcomes. Forty-four men completed the Trier Social Stress Test while their female partners observed the situation, either via real-life (one-way mirror) or virtual (video) observation modality. Later, the couples collected diurnal cortisol samples over two weekdays. Hierarchical linear modeling indicated that the degree to which couples covaried in their daily cortisol secretion was associated with the female partner's cortisol stress resonance in the laboratory, and that this association was stronger if stress resonance was assessed in the real-life observation condition. Specifically, women with higher cortisol stress resonance were more closely linked to their partner's diurnal cortisol secretion. Neither momentary partner presence during sampling nor relationship duration or quality accounted for the association. By showing that covariation in the laboratory has ecological validity in naturalistic conditions, these results make an important methodological contribution to the study of dyadic processes. Given that close relationships exert immense influence over individual health outcomes, understanding the association between acute and chronic physiological linkage may provide important insight into the mechanisms by which close relationships impact well-being.

Regulation of the corticosteroid signalling system in rainbow trout HPI axis during confinement stress

This study aims to shed light on corticosteroid regulation of stress in teleost fish with focus on the corticosteroid signalling system. The role of the mineralocorticoid-like hormone 11-deoxycorticosterone (DOC) in fish is still enigmatic, as is the function of the mineralocorticoid receptor, MR. Low plasma DOC levels and ubiquitous tissue distribution of MR question the physiological relevance of the mineralocorticoid-axis. Furthermore, the particular purpose of each of the three corticosteroid receptors in fish, the glucocorticoid receptors, GR1 and GR2, and the MR, is still largely unknown. Therefore we investigate the regulation of cortisol and DOC in plasma and mRNA levels of MR, GR1 and GR2 in the HPI-axis tissues (hypothalamus, pituitary and interrenal gland) during a detailed confinement stress time-course. Here we show a sustained up-regulation of plasma DOC levels during a confinement stress time-course. However, the low DOC levels compared to cortisol measured in the plasma do not favour an activity of DOC through MR receptors. Furthermore, we show differential contribution of the CRs in regulation and control of HPI axis activity following confinement stress. Judged by the variation of mRNA levels negative feedback regulation of cortisol release occurs on the level of the pituitary via MR and on the level of the interrenal gland via GR2. Finally, asa significant effect of confinement stress on CR expressions was observed in the pituitary gland, we completed this experiment by demonstrating that corticosteroid receptors (GR1, GR2 and MR) are co-expressed in the ACTH cells located in the adenohypophysis. Overall, these data suggest the involvement of these receptors in the regulation of the HPI axis activity by cortisol.

Plasma cortisol response cannot be classically conditioned in a taste-endocrine paradigm in humans.

Peripheral immune responses can be modified by associative learning procedures. Less is known, however, whether and to what extent neuroendocrine parameters can be classically conditioned. In this randomized double-blind study, we modified an established paradigm to behaviorally condition endocrine responses in humans. Thirty-one healthy male participants received a distinctively flavored green drink as the conditioned stimulus (CS) and intravenous injections of corticotropin-releasing hormone (CRH) (CRH group, N=17) or NaCl (placebo group, N=14) as the unconditioned stimulus (US) during two subsequent acquisition trials. Plasma levels of cortisol and noradrenaline, heart rate, and psychological parameters were analyzed before and 15, 30, 60, 120, and 180min after injection. The two acquisition trials were followed by two evocation trials, during which participants underwent the same procedure but now receiving NaCl injections. CRH administration induced pronounced increases in cortisol and noradrenaline plasma concentrations, heart rate, and anxiety levels. However, re-exposure to the CS during evocations trials did not provoke conditioned increases in neuroendocrine parameters. Median split of the CRH group based on the cortisol baseline level into "cort-high" and "cort-low" subgroups showed that the "cort-high" subgroup displayed a significantly increased cortisol production on evocation days compared to the "cort-low" subgroup and the placebo group. This taste-endocrine paradigm employing CRH injection as the US in healthy male volunteers failed to induce a behaviorally conditioned cortisol release as a learned endocrine response. Future studies should clarify a possible role of higher baseline cortisol levels in perhaps facilitating a conditioned cortisol response.

Effect of laparotomy on the pituitary-adrenal axis in dogs.

OBJECTIVE To assess effects of major abdominal surgery on serum cortisol and aldosterone and plasma canine ACTH (cACTH) concentrations. ANIMALS 39 healthy dogs undergoing laparotomy during veterinary student surgical laboratories. PROCEDURES Blood samples were obtained before and at completion of surgery. Serum cortisol and aldosterone and plasma cACTH concentrations were measured by use of validated radioimmunoassays. Changes in concentrations (postoperative concentration minus preoperative concentration) were calculated. Data were analyzed by use of the Wilcoxon signed rank test, Pearson correlation analysis, and Mann-Whitney rank sum test. RESULTS Cortisol, aldosterone, and cACTH concentrations increased significantly from before to after surgery. Although cortisol and aldosterone concentrations increased in almost all dogs, cACTH concentrations decreased in 6 of 32 (19%) dogs. All dogs had preoperative cortisol concentrations within the reference range, but 24 of 39 (62%) dogs had postoperative concentrations above the reference range. A correlation between the change in cACTH concentration and the change in cortisol concentration was not detected. CONCLUSIONS AND CLINICAL RELEVANCE Laparotomy caused a significant increase in serum cortisol and aldosterone concentrations. In most dogs, but not all dogs, plasma cACTH concentrations increased. Lack of correlation between the change in cACTH concentration and the change in cortisol concentration suggested that increased postoperative cortisol concentrations may have been attributable to ACTH-independent mechanisms, an early ACTH increase that caused a sustained cortisol release, or decreased cortisol clearance. Further studies are indicated to evaluate the effects of various anesthetic protocols and minimally invasive surgical techniques on the stress response.

Distinct Trajectories of Cortisol Response to Prolonged Acute Stress Are Linked to Affective Responses and Hippocampal Gray Matter Volume in Healthy Females.

The development of robust laboratory procedures for acute stress induction over the last decades has greatly advanced our understanding of stress responses in humans and their underlying neurobiological mechanisms. Nevertheless, attempts to uncover linear relationships among endocrine, neural, and affective responses to stress have generally yielded inconsistent results. Here, 79 healthy females completed a well established laboratory procedure of acute stress induction that was modified to prolong its effect. Endocrinological and subjective affect assessments revealed stress-induced increases in cortisol release and negative affect that persisted 65 and 100 min after stress onset, respectively, confirming a relatively prolonged acute stress induction. Applying latent class linear mixed modeling on individuals' patterns of cortisol responses identified three distinct trajectories of cortisol response: the hyper-response (n = 10), moderate-response (n = 21), and mild-response (n = 48) groups. Notably, whereas all three groups exhibited a significant stress-induced increase in cortisol release and negative affect, the hyper-response and mild-response groups both reported more negative affect relative to the moderate-response group. Structural MRI revealed no group differences in hippocampal and amygdala volumes, yet a continuous measure of cortisol response (area under the curve) showed that high and low levels of stress-induced cortisol release were associated with less hippocampal gray matter volume compared with moderate cortisol release. Together, these results suggest that distinct trajectories of cortisol response to prolonged acute stress among healthy females may not be captured by conventional linear analyses; instead, quadratic relations may better describe links between cortisol response to stress and affective responses, as well as hippocampal structural variability.SIGNIFICANCE STATEMENT Despite substantial research, it is unclear whether and how individual neuroendocrine stress response patterns are linked to affective responses to stress and structural variability in neuroendocrine regulatory brain regions. By applying latent class linear mixed modeling on individuals' patterns of cortisol responses to a prolonged acute stressor, we identified three distinct trajectories of cortisol response. Relative to the group showing a moderate cortisol response, groups characterized by hyper and mild cortisol response were both associated with more negative affect. Moreover, a continuous measure of cortisol response showed that high and low levels of stress-induced cortisol release correlated with reduced hippocampal gray matter volume. Given that neuroendocrine stress responses are conceptualized as biomarkers of stress susceptibility, these insights may have clinical implications.

Mechanisms of Mitochondrial Redox Signaling in Psychosocial Stress-Responsive Systems: New Insights into an Old Story.

Psychosocial stress is associated with alterations in serum glucocorticoids and cytokines, such as interleukin-6 (IL-6) and IL-1β, which functionally interact. However, the molecular mechanisms and physiological relationship between the two systems within the context of stress exposure are not well characterized. Recent Advances: Extracellular IL-6, which stimulates the release of cortisol from the zona fasciculata of the adrenal cortex, mediates its intracellular effects by tyrosine phosphorylation of the transcription factor signal transducer and activator of transcription 3 (STAT3). Mitochondrial electron transfer reactions are involved in both STAT3-driven ATP production in oxidative respiration and adrenocortical steroid biosynthesis. The role of STAT3 in oxidative respiration and steroidogenesis suggests that it integrates both nuclear and mitochondrial actions, thereby preserving main steps of glucocorticoid biosynthesis in the adrenal gland under psychosocial stress. This review discusses the notion that these two pathways are together simultaneously involved in protection against chronic stressors. Linking the function of cytokines and main components of the hypothalamic-pituitary-adrenal (HPA) axis to molecular mechanisms of mitochondrial redox signaling will be essential for a better understanding of the relevant stress-responsive systems engaged in stress vulnerability. Antioxid. Redox Signal. 28, 760-772.

Daily administration of paraprobiotic Lactobacillus gasseri CP2305 ameliorates chronic stress-associated symptoms in Japanese medical students

Administration of Lactobacillus gasseri CP2305 for 4weeks improved stress-associated behaviours in healthy young adults and clinical symptoms in patients with irritable bowel syndrome. The present study was designed to confirm the stress-relieving effects of heat-inactivated, washed CP2305 (paraprobiotic CP2305) on 69 sixth-year medical students (40 males and 29 females) preparing to take the national examination for medical practitioners. Administration of the paraprobiotic CP2305 for 12weeks significantly improved sleep quality assessed by both the Pittsburgh Sleep Quality Index and a one-channel sleep electroencephalogram during the pre-examination period compared with that of the placebo administration. The paraprobiotic CP2305 administration also prevented increases in basal salivary cortisol release and expression of stress-responsive microRNAs (miR-144 and miR-144∗). In addition to the improvement in parasympathetic nerve activity, the paraprobiotic CP2305 normalized the bowel habits under the stressful conditions. Based on these results, we propose that paraprobiotic CP2305 may be used as a para-psychobiotic.

Salivary cortisol and cortisone in the clinical setting

A resurgence of interest in salivary biomarkers has generated evidence for their value in assessing adrenal function. The advantages of salivary measurements include only free hormone is detected, samples can be collected during normal daily routines and stress-induced cortisol release is less likely to occur than during venepuncture. We review the use of salivary biomarkers to diagnose and monitor patients for conditions of cortisol excess and deficiency and discuss the value of measuring salivary cortisone versus salivary cortisol. Developments in laboratory techniques have enabled the measurement of salivary hormones with a high level of sensitivity and specificity. In states of altered cortisol binding, salivary biomarkers are more accurate measures of adrenal reserve than serum cortisol. Salivary cortisone is a superior marker of serum cortisol compared with salivary cortisol, specifically when serum cortisol is low and during hydrocortisone therapy when contamination of saliva may result in misleading salivary cortisol concentrations. Salivary cortisol and cortisone can be used to assess cortisol excess, deficiency and hydrocortisone replacement, with salivary cortisone having the advantage of detection when serum cortisol levels are low and there is no interference from oral hydrocortisone.

Mindfulness-Based Stress Reduction Program on Chronic Low-Back Pain: A Study Investigating the Impact on Endocrine, Physical, and Psychologic Functioning.

To explore the impact of the Mindfulness-Based Stress Reduction (MBSR) program on pain severity and endocrine, physical, and psychologic functioning in patients with chronic low-back pain (CLBP). A total of 28 participants were enrolled in the study between January and June 2014; 17 participants were sequentially sampled for an 8-week MBSR program, and 11 were placed on a waitlist control group. Pain severity, quality of life (QOL), global psychologic functioning, and depression were assessed at baseline, at the end of treatment, and 4-5 months post-treatment for both groups. Morning and evening salivary cortisol was assessed at multiple time points in participants in the MBSR group. In comparison with baseline, evening cortisol release showed a significant increase post-treatment. Significant differences between groups were found in pain severity. Medium-to-large effect sizes were found for between-group differences in both pain severity and QOL. The cortisol increase in the MBSR group is a promising finding, in the context of CLBP hypocortisolism. Data show that the effects of the MBSR treatment may take time to surface. However, due to small sample size, decisive interpretation of findings is limited. Nevertheless, the MBSR program may show promise for CLBP and should be an avenue for further investigation through larger clinical trials within healthcare systems.

“Sex differences in a real academic stressor, cognitive appraisal and the cortisol response”

Women and men differ in their physiological and psychological stress response but only a few studies have analyzed this sex difference in a naturalistic setting and focused on cognitive stress appraisal. In the present study, the salivary cortisol concentration of 24 female and 22 male subjects was measured before and several times after an oral academic presentation given by themselves (stress condition) or given by a fellow student (control condition). Feelings of subjective stress and nervousness were assessed simultaneously to the saliva samples and a questionnaire for cognitive stress appraisal was conducted right before the oral presentation. In the stress condition, the presentation led to a significantly higher cortisol increase than in the control condition. Sex differences were shown concerning the subjective stress feelings, which were higher in women, whereas there were no sex differences in cortisol release. Women showed a disadvantageous cognitive appraisal compared to men in both conditions. There was an interaction effect of sex and condition: women reported to feel equally challenged in both conditions whereas men felt significantly more challenged by their own presentation than by the presentations of their fellow students. The result that men's cognitive appraisal was more influenced by an academic stressor than women's and that women felt subjectively more stressed whereas there was no difference concerning the cortisol response is discussed in consideration of evolutional and biological aspects.

High hair cortisol concentrations predict worse cognitive outcome after stroke: Results from the TABASCO prospective cohort study

Background and purposeThe role of stress-related endocrine dysregulation in the development of cognitive changes following a stroke needs further elucidation. We explored this issue in a longitudinal study on stroke survivors using hair cortisol concentrations (HCC), a measure of integrated long-term cortisol levels. MethodsParticipants were consecutive cognitively intact first-ever mild-moderate ischemic stroke/transient ischemic attack (TIA) survivors from the Tel Aviv Brain Acute Stroke Cohort (TABASCO) study. They underwent 3T magnetic resonance imaging (MRI) scanning and were cognitively assessed at admission, and at 6, 12 and 24 months post-stroke. Scalp hair samples were obtained during the initial hospitalization. ResultsFull data on baseline HCC, MRI scans and 2 years neuropsychological assessments were available for 65 patients. Higher HCC were significantly associated with a larger lesion volume and with worse cognitive results 6, 12 and 24 months post-stroke on most of the neurocognitive tests. 15.4% of the participants went on to develop clinically significant cognitive decline in the follow-up period, and higher HCC at baseline were found to be a significant risk factor for this decline, after adjustment for age, gender, body mass index and APOE e4 carrier status (HR=6.553, p=0.038). ConclusionsOur findings suggest that individuals with higher HCC, which probably reflect higher long-term cortisol release, are prone to develop cognitive decline following an acute stroke or TIA.

Lust for violence: Appetitive aggression as a fundamental part of human nature

AbstractAppetitive aggression describes a biologically-driven form of aggressive behaviour and violence characterized by positive affect. In contrast to reactive aggression, which has the function of resisting a threat, and reducing concomitant negative emotional arousal and anger, appetitive aggression underlies the pleasure of violence. A prototypical example is hunting, which can in turn transfer to the hunting of humans and can even result in bloodlust, and killing for its own sake. At the physiological level, this morally illicit pleasure is accompanied by an adrenalin surge, the release of cortisol and endorphins. In order to activate reward systems via appetitive aggression, their moral and cultural restraints need to be overridden. For example, armed groups work to dehumanize the enemy. Once initiated, a positive feedback loop is generated: As the individual commits more acts of violence with elements of positive affect, the tendency to commit them grows, and they begin to be perceived more positively. A latent passion for fighting and dominance can probably be evoked in almost all men and in some women. The cumulative outcome of whole groups, tribes, or communities enacting this aggression is war and destruction, to the point of trying to extinguish entire ethnic groups:“… and yes, human beings, hundreds of thousands of otherwise normal people, not professional killers, did it.”(from “The Killers in Rwanda Speak” by Jean Hatzfeld, 2005). Thus, appetitive aggression, the disposition towards a lust for violence, is by no means a psychopathological anomaly but an intrinsic part of the human behavioural repertoire. Morality, culture and the state monopoly on violence constitute the guards that regulate aggression potential and to channel it into socially useful forms.

Adrenal cortex reactivity in dairy cows differs between lactational stages and between different feeding levels

Changes in ACTH challenge test characteristics in dairy cows changing their physiological status at different lactational stages and different feeding levels were not investigated in terms of repeatability yet. In 23 multiparous Holstein cows (10 cows fed a sole fresh herbage diet without concentrate, 13 cows fed with concentrate), three ACTH challenge tests were performed: once during pregnancy shortly prior to drying off (T1), and in week 3 (T2) and 8 (T3) after parturition. Test characteristics were correlated to performance and metabolic parameters: DMI, BW, energy balance (EB), plasma concentrations of free fatty acids (NEFA) and beta-hydroxybutyrate (BHB). Basal plasma cortisol concentrations were higher at T1 compared with T2 and T3 (p<.05). The adrenal cortex sensitivity (expressed as total AUC (AUCt ) of cortisol response after ACTH application) was lowest at T2 compared with T1 and T3 (p<.05). Ranking of the individual animals' responses was not repeatable between time points of the ACTH tests. Enhancing the energy deficiency during early lactation by omission of concentrate did not affect baseline cortisol concentrations in plasma, but decreased peak height at T2 (p<.05). Baseline plasma cortisol concentrations were positively correlated with cortisol peak values after ACTH application, previous lactation performance, milk yield and BW (p<.05). The AUCt was positively correlated with baseline cortisol concentrations, EB and DMI. Cortisol release after ACTH injection was lower in animals with high plasma concentrations of NEFA, BHB and with higher contents of fat and free fatty acids in milk (p<.05). Cortisol peak height after ACTH administration was higher in cows with a more positive EB, higher DMI and lower plasma concentrations of NEFA and BHB. In summary, cortisol responses to ACTH challenges in this study were not repeatable in dairy cows changing their physiological status.

Physiological reactivity to spontaneously occurring seizure activity in dogs with epilepsy and their carers

There is a complex bidirectional relationship between stress and epilepsy. Stressful stimuli and subsequent cortisol release act as a trigger for seizure activity in some individuals with epilepsy, and seizure activity itself may act as a stressor to the affected individual. Epilepsy is the most common chronic neurological condition in domestic dogs and requires chronic management by their human carers, impacting upon the quality of life of both dog and carer. Seizures occur unpredictably and may be stressful for carers to witness and manage. In the present study we investigated the role of seizure activity as a stressor, measuring the effect of spontaneously occurring seizure activity in dogs with epilepsy upon their own cortisol levels and that of their carers. Furthermore, we tested whether individual differences in HPA reactivity were associated with owner personality characteristics and the quality of the dog–carer relationship. Saliva samples were obtained from sixteen dog-carer dyads in the home setting 20 and 40minute post-seizure, and at time-matched points on the following (non-seizure) day. Significant differences in cortisol levels were found in dogs at 40minute post-seizure (265.1% increase), and at 20minute post-seizure in their carers (40.5% increase). No associations were found between cortisol reactivity and the strength of the dog-carer bond. Carers with higher neuroticism scores exhibited higher cortisol levels at both post-seizure sampling points. As there was a gender bias in the carer sample (15/16 were female), and there are known sex differences in cortisol reactivity in response to psychological stress, the conclusions of this study may be limited to female carers. These findings are the first to objectively demonstrate the acutely stressful effects of seizures in dogs with epilepsy and their carers.

Physiological and behavioral flexibility to an acute CO2 challenge, within and between genotypes in rainbow trout

Adaptive capacities, governing the ability of animals to cope with an environmental stressor, have been demonstrated to be strongly dependent upon genetic factors. Two isogenic lines of rainbow trout, previously described for their sensitivity and resilience to an acute confinement challenge, were used in the present study to investigate whether adaptive capacities remain consistent when fish are exposed to a different type of challenge. For this purpose, the effects of a 4-hour hypercapnia (CO2 increase) challenge at concentrations relevant in aquaculture conditions are described for the two isogenic lines. Oxygen consumption, cortisol release, group dispersion and group swimming activity were measured before, during and after the challenge. Sensitivity and resilience for each measure were extracted from temporal responses and analyzed using multivariate statistics. The two fish lines displayed significant differences in their cortisol response, translating differences in the stress axis sensitivity to the stressor. On the contrary, both lines showed, for other measures, similar temporal patterns across the study. Notable within line variability in the stress response was observed, despite identical genome between fish. The results are discussed in the context of animal robustness.

Is borderline personality disorder a neuroendocrine disease?

IntroductionBorderline personality disorder (BPD) is a disabling heterogeneous psychiatric disorder characterized by poor affect regulation and impulse control, with a high reactivity and vulnerability to stress. It has been hypothesized that these patients may have a dysregulation of the neuroendocrine system.AimsThe goal of this work is to systematically review the scientific knowledge regarding the role of the neuroendocrine system in the physiopathology of BPD.MethodsThe literature was reviewed by online searching using PubMed®. The authors selected scientific papers with the words “borderline personality disorder” and “neuroendocrine”/“endocrine” in the title and/or abstract, published in English.Results and discussionThere is scientific evidence for an enhanced cortisol release and HPA axis hyperactivity in BPD. The dexamethasone suppression test has been used in BPD, finding high rates of non-suppressors in that sample. There also seems to be a reduced volume of the amygdala and anterior cingulate cortex, suggesting an involvement of those regions in the emotional disturbances in BPD. Symptoms of impulsivity, aggression and suicidal behavior seem to be strongly mediated by the serotonergic system. The available research suggests a serotoninergic dysfunction in BPD, with lower levels of serotonin in those patients.ConclusionsThere seems to be several neuroendocrine changes related to BPD, namely a hyperactivity of the HPA axis with stimulated cortisol release together with disturbances of the serotonergic system. Also some brain structural alterations in BPD are scientifically depicted. Further studies are needed to clarify the neurobiology of BPD improving both psychotherapeutic and psychopharmacological treatment in these patients.Disclosure of interestThe authors have not supplied their declaration of competing interest.