A Comprehensive Overview on Stress Neurobiology: Basic Concepts and Clinical Implications

Autonomic nervous system and endocrine system response to upper or lower cervical spine mobilization in males with persistent post-concussion symptoms: a proof-of-concept trial

INTRODUCTION

The peripheral stress response, consisting of the autonomic nervous system (ANS) and hypothalamic pituitary adrenal-axis (HPA-axis), functions to maintain homeostasis in response to stressors. Cervical spine manual therapy has been shown to differentially modulate the stress response in healthy populations. No study has investigated whether cervical spine mobilizations can differentially modulate the stress response in individuals with persistent post-concussion symptoms (PPCS), a population characterized by a dysfunctional stress response.

METHODS

A randomized, controlled, parallel design trial was performed to investigate whether upper or lower cervical spine mobilization can differentially modulate components of the stress response in individuals with PPCS. The outcomes were salivary cortisol (sCOR) concentration (primary) and the HRV metric, rMSSD, measured with a smartphone application (secondary). Nineteen males diagnosed with PPCS, aged 19-35, were included. Participants were randomly assigned into either intervention group, upper (n = 10) or lower (n = 9) cervical spine mobilization. Each outcome was collected at different time points, pre- and post-intervention. Statistical analyses were performed using the Friedman's Two-Way ANOVA, Mann-Whitney U test, and Wilcoxon Signed Rank Test.

RESULTS

There was a statistically significant within-group reduction in sCOR concentration 30 minutes following lower cervical spine mobilizations and statistically significant within-group increase in rMSSD 30 minutes following upper cervical spine mobilizations.

CONCLUSION

The results of this trial provide preliminary evidence for cervical spine mobilizations to differentially modulate components of the stress response at specific time points. Understanding the mechanisms of the effect of cervical spine mobilizations on the stress response provides a novel rationale for selecting cervical spine mobilizations to rehabilitate individuals with PPCS.

Maternal perceived stress, household disorder, eating behaviors and adiposity of women and their children

BACKGROUND

Stress is associated with physiological and behavioral adaptations that increase the risk for obesity and related diseases in adults and children. Mechanisms linking stress to chronic disease are diverse and not fully elucidated, but research suggests stress may impact eating behaviors and increase food intake and thereby, risk for obesity.

OBJECTIVE

The purpose of this study was to test the hypotheses that women's perceived stress and household disorder are associated with more uncontrolled and emotional eating among women, more food responsiveness and emotional overeating among their children, and greater adiposity in both women and their children.

METHODS

Women (n = 86) completed the Perceived Stress Scale, Confusion, Hubbub and Order Scale, Three Factor Eating Questionnaire, and Child Eating Behavior Questionnaire. Total body fat (%) was measured via dual-energy X-ray absorptiometry. Linear regression models evaluated associations of perceived stress and household disorder with eating behaviors and adiposity of women and their children (4-10 years old).

RESULTS

In a sample of predominantly non-Hispanic Black women (84.9%, n = 73), more perceived stress and household disorder were associated with more uncontrolled and emotional eating (p < 0.05). Women's perceived stress was not associated with their children's eating behaviors; however, household disorder was positively associated with children's food responsiveness and emotional overeating (p < 0.05). Perceived stress and household disorder were not associated with adiposity of women or their children.

CONCLUSIONS

These findings suggest household disorder may be a factor for home-based interventions to consider when addressing eating behaviors among families with children.

Stress, hypothalamic-pituitary-adrenal axis, hypothalamic-pituitary-gonadal axis, and aggression

This comprehensive review explores the intricate relationship between the hypothalamic-pituitary-adrenal (HPA) axis, the hypothalamic-pituitary-gonadal (HPG) axis, and aggression. It provides a detailed overview of the physiology and functioning of these axes, as well as the implications for aggressive behavior. The HPA axis, responsible for the stress response, is activated in response to various stressors and can influence aggressive behavior. Glucocorticoids, such as cortisol, play a crucial role in stress-induced activation of the HPA axis and have been implicated in aggressive tendencies. Chronic stress can dysregulate the HPA axis, leading to alterations in cortisol levels and potentially contributing to aggressive behavior. The HPG axis, particularly the androgen hormone testosterone, is also closely linked to aggression. Animal and human studies have consistently shown a positive association between testosterone levels and aggression. The androgen receptors in the brain's neural circuitry play a critical role in modulating aggressive behavior. Interactions between the HPA and HPG axes further contribute to the regulation of aggression. Feedback mechanisms and crosstalk between these axes provide a complex system for the modulation of both stress and reproductive functions, which can impact aggressive behavior. Additionally,the influence of stress on reproductive functions, particularly the role of androgens in stress-induced aggression, adds further complexity to this relationship. The review also discusses the future directions and implications for clinical interventions. Understanding the neurobiological mechanisms underlying aggression requires integrating molecular, cellular, and circuit-level approaches. Translational perspectives, including animal models and human studies, can bridge the gap between basic research and clinical applications. Finally, therapeutic strategies for aggression-related disorders are explored, highlighting the importance of targeted interventions based on a comprehensive understanding of the interactions between the HPA and HPG axes. In conclusion, this review provides a comprehensive overview of the physiological and neurobiological mechanisms underlying aggression, with a specific focus on the interplay between the HPA and HPG axes. By elucidating the complex interactions between stress, hormones, and aggressive behavior, this research paves the way for future investigations and potential therapeutic interventions for aggression-related disorders.

Chronic stimulation desensitizes β2-adrenergic receptor responses in natural killer cells

Adrenergic receptors (ARs) are preferentially expressed by innate lymphocytes such as natural killer (NK) cells. Here, we study the effect of epinephrine-mediated stimulation of the β2-adrenergic receptor (β2AR) on the function of human NK cells. Epinephrine stimulation inhibited early NK cell signaling events and blocked the function of the integrin LFA-1. This reduced the adhesion of NK cells to ICAM-1, explaining how NK cells are mobilized into the peripheral blood upon epinephrine release during acute stress or exercise. Additionally, epinephrine stimulation transiently reduced NK cell degranulation, serial killing, and cytokine production and affected metabolic changes upon NK cell activation via the cAMP-protein kinase A (PKA) pathway. Repeated exposure to β2AR agonists resulted in the desensitization of the β2AR via a PKA feedback loop-initiated G-protein switch. Therefore, acute epinephrine stimulation of chronically β2AR stimulated NK cells no longer resulted in inhibited signaling and reduced LFA-1 activity. Sustained stimulation by long-acting β2-agonists (LABA) not only inhibited NK cell functions but also resulted in desensitization of the β2AR. However, peripheral NK cells from LABA-treated asthma patients still reacted unchanged to epinephrine stimulation, demonstrating that local LABA administration does not result in detectable systemic effects on NK cells.

Analyzing and identifying predictable time range for stress prediction based on chaos theory and deep learning

Propose

Stress is a common problem globally. Prediction of stress in advance could help people take effective measures to manage stress before bad consequences occur. Considering the chaotic features of human psychological states, in this study, we integrate deep learning and chaos theory to address the stress prediction problem.

Methods

Based on chaos theory, we embed one's seemingly disordered stress sequence into a high dimensional phase space so as to reveal the underlying dynamics and patterns of the stress system, and meanwhile are able to identify the stress predictable time range. We then conduct deep learning with a two-layer (dimension and temporal) attention mechanism to simulate the nonlinear state of the embedded stress sequence for stress prediction.

Results

We validate the effectiveness of the proposed method on the public available Tesserae dataset. The experimental results show that the proposed method outperforms the pure deep learning method and Chaos method in both 2-label and 3-label stress prediction.

Conclusion

Integrating deep learning and chaos theory for stress prediction is effective, and can improve the prediction accuracy over 2% and 8% more than those of the deep learning and the Chaos method respectively. Implications and further possible improvements are also discussed at the end of the paper.

Stronger association between morning serum cortisol level and diurnal time in range in type 2 diabetes?

BACKGROUND

The hypothalamic-pituitary-adrenal axis is thought to play a vital role in glucose homeostasis and diabetes. This study investigated the association between morning serum cortisol and time in range (TIR), including daytime TIR, in type 2 diabetes (T2DM).

METHODS

310 patients with T2DM had serum cortisol measured at 8 a.m. All participants underwent continuous glucose monitoring (CGM) for three consecutive days, then TIR and glycemic variability (GV) parameters were evaluated. Using 100 g standard steamed bread meal test, blood glucose, C peptide and insulin at different points were collected to assess insulin sensitivity and islet function.

RESULTS

Patients with higher serum cortisol exhibited lower TIR and TITR (P < 0.001). Spearman correlation analysis showed that the negative correlation between cortisol and daytime TIR (r=-0.231, P < 0.001) was stronger than that of overnight TIR (r=-0.134, P = 0.028). Similarly, there existed a negative correlation between cortisol and pancreatic function indicators such as HOMA-β, insulinogenic index (IGI), area under the curve of C-peptide within half an hour (AUCCp0.5 h) and three hours (AUCCp3h) (r=-0.248, -0.176, -0.140, -0.185, respectively, P < 0.05). In contrast, cortisol was positively associated with TAR (r = 0.217, P < 0.001) and GV parameters including MBG, MAGE, LAGE, HBGI, MODD, ADDR (P of MAGE and MODD > 0.05). Multiple stepwise regression revealed that cortisol was an independent contributor of TIR, TITR and diurnal TIR, with diurnal TIR of stronger relevance.

CONCLUSIONS

Morning serum cortisol is negatively correlated with TIR, especially diurnal TIR and positively associated with GV parameters. Inappropriate cortisol secretion may have an adverse influence on glucose homeostasis in T2DM.

Senescence-like Phenotype After Chronic Exposure to Isoproterenol in Primary Quiescent Immune Cells

Chronic stress is associated with a higher risk for carcinogenesis as well as age-related diseases and immune dysfunction. There is evidence showing that psychological stress can contribute to premature immunosenescence. Therefore, the question arose whether chronic exposure to catecholamine could drive immune cells into senescence. Peripheral blood mononuclear cells were isolated from whole blood. After repeated ex vivo treatment with isoproterenol, an epinephrine analog, well-established senescence biomarkers were assessed. We found (i) DNA double-strand break induction, (ii) telomere shortening, (iii) failure to proliferate, (iv) higher senescence-associated β-galactosidase activity, (v) decreases in caspases 3 and 7 activity, and (vi) strong upregulation of the proteoglycan versican accompanied by increased cellular adhesion suggesting the induction of a senescence-like phenotype. These results emphasize the complexity of the effect of isoproterenol on multiple cellular processes and provide insights into the molecular mechanisms of stress leading to immunosenescence.

Mindfulness-Based Interventions and the Hypothalamic-Pituitary-Adrenal Axis: A Systematic Review

BACKGROUND

Numerous studies have evaluated the effect that mindfulness-based interventions (MBIs) have on multiple health outcomes. For its part, stress is a natural response to environmental disturbances and within the associated metabolic responses, alterations in cortisol levels and their measurement in different tissues are a way to determine the stress state of an individual. Therefore, it has been proposed that MBIs can modify cortisol levels.

METHODS AND RESULTS

The objective of this systematic review was to analyze and summarize the different studies that have evaluated the effect of MBIs on cortisol levels. The following databases were consulted: MEDLINE, AMED, CINAHL, Web of Science, Science Direct, PsycINFO, SocINDEX, PubMed, the Cochrane Library and Scopus. The search terms "mindfulness", "mindfulness-based interventions" and "cortisol" were used (and the search was limited to studies from January 1990 to May 2024). In order to reduce selection bias, each article was scrutinized using the JBI Critical Appraisal Checklist independently by two authors. We included those studies with specified intervention groups with at least one control group and excluded duplicate studies or those in which the intervention or control group was not adequately specified. Significant changes in cortisol following MBIs were found in 25 studies, while 10 found no changes. The small sample size, lack of randomization, blinding, and probable confounding and interaction variables stand out in these studies.

CONCLUSION

MBIs have biological plausibility as a means of explaining a positive effect on cortisol levels; however, the weakness of the studies and the absence of robust designs makes it difficult to establish a causal association between both variables.

REGISTRATION NUMBER

INPLASY2024110017.

Hypothalamic corticotropin-releasing hormone neurons modulate sevoflurane anesthesia and the post-anesthesia stress responses

General anesthesia (GA) is an indispensable procedure necessary for safely and compassionately administering a significant number of surgical procedures and invasive diagnostic tests. However, the undesired stress response associated with GA causes delayed recovery and even increased morbidity in the clinic. Here, a core hypothalamic ensemble, corticotropin-releasing hormone neurons in the paraventricular nucleus of the hypothalamus (PVHCRH neurons), is discovered to play a role in regulating sevoflurane GA. Chemogenetic activation of these neurons delay the induction of and accelerated emergence from sevoflurane GA, whereas chemogenetic inhibition of PVHCRH neurons accelerates induction and delays awakening. Moreover, optogenetic stimulation of PVHCRH neurons induce rapid cortical activation during both the steady and deep sevoflurane GA state with burst-suppression oscillations. Interestingly, chemogenetic inhibition of PVHCRH neurons relieve the sevoflurane GA-elicited stress response (e.g., excessive self-grooming and elevated corticosterone level). These findings identify PVHCRH neurons modulate states of anesthesia in sevoflurane GA, being a part of anesthesia regulatory network of sevoflurane.

Sex Differences in the Neuroendocrine Stress Response: A View from a CRH-Reporting Mouse Line

Corticotropin-releasing hormone (CRH) neurons within the paraventricular hypothalamic nucleus (PVH) play a crucial role in initiating the neuroendocrine response to stress and are also pivotal in coordination of autonomic, metabolic, and behavioral stress reactions. Although the role of parvocellular CRHPVH neurons in activation of the hypothalamic-pituitary-adrenal (HPA) axis is well established, the distribution and function of CRH-expressing neurons across the whole central nervous system are less understood. Stress responses activate complex neural networks, which differ depending on the type of stressor and on the sex of the individual. Because of the technical difficulties of localizing CRH neurons throughout the rodent brain, several CRH reporter mouse lines have recently been developed. In this study, we used Crh-IRES-Cre;Ai9 reporter mice to examine whether CRH neurons are recruited in a stressor- or sex-specific manner, both within and outside the hypothalamus. In contrast to the clear sexual dimorphism of CRH-mRNA-expressing neurons, quantification of CRH-reporting, tdTomato-positive neurons in different stress-related brain areas revealed only subtle differences between male and female subjects. These results strongly imply that sex differences in CRH mRNA expression occur later in development under the influence of sex steroids and reflects the limitations of using genetic reporter constructs to reveal the current physiological/transcriptional status of a specific neuron population. Next, we compared the recruitment of stress-related, tdTomato-expressing (putative CRH) neurons in male and female Crh-IRES-Cre;Ai9 reporter mice that had been exposed to predator odor. In male mice, fox odor triggered more c-Fos in the CRH neurons of the paraventricular hypothalamic nucleus, central amygdala, and anterolateral bed nucleus of the stria terminalis compared to females. These results indicate that male mice are more sensitive to predator exposure due to a combination of hormonal, environmental, and behavioral factors.

The Role of Insulin Within the Socio-Psycho-Biological Framework in Type 2 Diabetes-A Perspective from Psychoneuroimmunology

The interplay between socio-psychological factors and biological systems is pivotal in defining human health and disease, particularly in chronic non-communicable diseases. Recent advancements in psychoneuroimmunology and mitochondrial psychobiology have emphasized the significance of psychological factors as critical determinants of disease onset, progression, recurrence, and severity. These insights align with evolutionary biology, psychology, and psychiatry, highlighting the inherent social nature of humans. This study proposes a theory that expands insulin's role beyond traditional metabolic functions, incorporating it into the Mitochondrial Information Processing System (MIPS) and exploring it from an evolutionary medicine perspective to explore its function in processing psychological and social factors into biological responses. This narrative review comprises data from preclinical animal studies, longitudinal cohort studies, cross-sectional studies, machine learning analyses, and randomized controlled trials, and investigates the role of insulin in health and disease. The result is a proposal for a theoretical framework of insulin as a social substance within the socio-psycho-biological framework, emphasizing its extensive roles in health and disease. Type 2 Diabetes Mellitus (T2DM) with musculoskeletal disorders and neurodegeneration exemplifies this narrative. We suggest further research towards a comprehensive treatment protocol meeting evolutionary expectations, where incorporating psychosocial interventions plays an essential role. By supporting the concept of 'insulin resilience' and suggesting the use of heart rate variability to assess insulin resilience, we aim to provide an integrative approach to managing insulin levels and monitoring the effectiveness of interventions. This integrative strategy addresses broader socio-psychological factors, ultimately improving health outcomes for individuals with T2DM and musculoskeletal complications and neurodegeneration while providing new insights into the interplay between socio-psychological factors and biological systems in chronic diseases.

Implication of locus coeruleus dysfunction in Prader-Willi syndrome: Insights from a mouse model

Prader-Willi syndrome (PWS) is a multisystemic disorder. Notably, many characteristic symptoms of PWS are correlated with locus coeruleus norepinephrine system (LC-NE) dysfunction, including impairment in arousal, learning, pain modulation, and stress-induced negative affective states. Although electrophysiological experiments in necdin-deficient mice, an established PWS animal model, have revealed decreased spontaneous neuronal firing activity in the LC and impaired excitability, the behavioral phenotypes related to LC-NE dysfunction remain unexplored. In this study, heterozygous necdin-deficient mice (B6.Cg-Ndntm1ky) were bred from wild-type (WT) females to generate WT (+m/+p) and heterozygous (+m/-p) animals. Compared to WT mice, Ndn + m/-p mice demonstrated impaired visual-spatial memory in the Y-maze test, reduced social interaction, impaired sexual recognition, and shorter falling latency on the Rotarod. Using the open field test (OFT) and elevated plus maze (EPM), we observed similar locomotion activity of Ndn + m/-p and WT mice, but Ndn + m/-p mice were less anxious. After acute restraint, Ndn + m/-p mice exhibited significant impairment in stress-induced anxiety. Additionally, the plasma norepinephrine surge following exposure to acute restraint stress was also impaired. Pretreatment with atomoxetine, a norepinephrine reuptake inhibitor aimed to enhance LC function, restored Ndn + m/-p mice to exhibit a normal response to acute restraint stress. Furthermore, by employing chemogenetic approaches to facilitate LC neuronal firing, post-stress anxious responses were also partially rescued in Ndn + m/-p mice. These data strongly suggest that LC dysfunction is implicated in the pathogenesis of stress-related neuropsychiatric symptoms in PWS. Manipulation of LC activity may hold therapeutic potential for patients with PWS.

Behavioral coping with chronic defeat stress in mice: A systematic review of current protocols

Social stress is the most significant source of chronic stress in humans and is commonly associated with health impairment. Individual differences in the behavioral coping responses to stress have been proposed to mediate the negative effects of stress on physical, behavioral and mental health. Animal models, particularly mice, offer valuable insights into the physiological and neurobiological correlates of behavioral coping strategies in response to chronic social stress. Here we aim to identify differences and similarities among stress protocols in mice, with particular attention to how neuroendocrine and/or behavioral responses vary according to different coping strategies, while highlighting the need for standardized approaches in future research. A systematic review was undertaken following the Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA statement). A total of 213 references were identified by electronic search, and after the screening, 18 articles were found to meet all the established criteria. We analyzed differences in the stress protocol, the characterization and classification of coping strategies and the physiological and behavioral differences according to coping. The results show that differences in behavioural expression under chronic social stress (coping) may also be associated with physiological differences and differential susceptibility to disease. However, this review also underlines the importance of a cautious interpretation of the results obtained. The lack of consistency in the nomenclature and procedures associated with the study of coping strategies for social stress, as well as the absence of a uniform classification, highlight the importance of using a common language when approaching the study of coping strategies. Thereby, this review encourages the development of a more defined method and criteria for assessing coping strategies, based on both behavioral and biological indicators.

Resilience to Chronic Stress Is Characterized by Circadian Brain-Liver Coordination

Background

Chronic stress has a profound impact on circadian regulation of physiology. In turn, disruption of circadian rhythms increases the risk of developing both psychiatric and metabolic disorders. To explore the role of chronic stress in modulating the links between neural and metabolic rhythms, we characterized the circadian transcriptional regulation across different brain regions and the liver as well as serum metabolomics in mice exposed to chronic social defeat stress, a validated model for studying depressive-like behaviors.

Methods

Male C57BL/6J mice underwent chronic social defeat stress, and subsequent social interaction screening identified distinct behavioral phenotypes associated with stress resilience and susceptibility. Stressed mice and their control littermates were sacrificed every 4 hours over the circadian cycle for comprehensive analyses of the circadian transcriptome in the hypothalamus, hippocampus, prefrontal cortex, and liver together with assessments of the circadian circulatory metabolome.

Results

Our data demonstrate that stress adaptation was characterized by reprogramming of the brain as well as the hepatic circadian transcriptome. Stress resiliency was associated with an increase in cyclic transcription in the hypothalamus, hippocampus, and liver. Furthermore, cross-tissue analyses revealed that resilient mice had enhanced transcriptional coordination of circadian pathways between the brain and liver. Conversely, susceptibility to social stress resulted in a loss of cross-tissue coordination. Circadian serum metabolomic profiles corroborated the transcriptome data, highlighting that stress-resilient mice gained circadian rhythmicity of circulating metabolites, including bile acids and sphingomyelins.

Conclusions

This study reveals that resilience to stress is characterized by enhanced metabolic rhythms and circadian brain-liver transcriptional coordination.

Effects of chronic stress on cognitive function - From neurobiology to intervention

Exposure to chronic stress contributes considerably to the development of cognitive impairments in psychiatric disorders such as depression, generalized anxiety disorder (GAD), obsessive-compulsive disorder (OCD), post-traumatic stress disorder (PTSD), and addictive behavior. Unfortunately, unlike mood-related symptoms, cognitive impairments are not effectively treated by available therapies, a situation in part resulting from a still incomplete knowledge of the neurobiological substrates that underly cognitive domains and the difficulty in generating interventions that are both efficacious and safe. In this review, we will present an overview of the cognitive domains affected by stress with a specific focus on cognitive flexibility, behavioral inhibition, and working memory. We will then consider the effects of stress on neuronal correlates of cognitive function and the factors which may modulate the interaction of stress and cognition. Finally, we will discuss intervention strategies for treatment of stress-related disorders and gaps in knowledge with emerging new treatments under development. Understanding how cognitive impairment occurs during exposure to chronic stress is crucial to make progress towards the development of new and effective therapeutic approaches.

Mechanisms underlying the health benefits of intermittent hypoxia conditioning

Intermittent hypoxia (IH) is commonly associated with pathological conditions, particularly obstructive sleep apnoea. However, IH is also increasingly used to enhance health and performance and is emerging as a potent non-pharmacological intervention against numerous diseases. Whether IH is detrimental or beneficial for health is largely determined by the intensity, duration, number and frequency of the hypoxic exposures and by the specific responses they engender. Adaptive responses to hypoxia protect from future hypoxic or ischaemic insults, improve cellular resilience and functions, and boost mental and physical performance. The cellular and systemic mechanisms producing these benefits are highly complex, and the failure of different components can shift long-term adaptation to maladaptation and the development of pathologies. Rather than discussing in detail the well-characterized individual responses and adaptations to IH, we here aim to summarize and integrate hypoxia-activated mechanisms into a holistic picture of the body's adaptive responses to hypoxia and specifically IH, and demonstrate how these mechanisms might be mobilized for their health benefits while minimizing the risks of hypoxia exposure.

Cognitive Disorders in Type 1 Diabetes: Role of Brain Glucose Variation, Insulin Activity, and Glucocorticoid Exposure

BACKGROUND

The number of patients with type 2 diabetes (T2D) and type 1 diabetes (T1D) is on the rise, partly due to a global increase in new T1D cases among children. Beyond the well-documented microvascular and macrovascular complications, there is now substantial evidence indicating that diabetes also impacts the brain, leading to neuropsychological impairments. The risk of developing neuropsychiatric symptoms is notably higher in childhood due to the ongoing maturation of the brain, which makes it more susceptible to damage. Despite this awareness, the specific effects of diabetes on cognitive function remain poorly understood.

SUMMARY

This review synthesizes literature on the impact of diabetes on cognition and its relationship with brain structural changes. It presents data and hypotheses to explain how T1D contributes to cognitive dysfunction, with a particular focus on children and adolescents. The emphasis on the pediatric population is intentional, as young diabetic patients typically have fewer comorbidities, reducing confounding factors and simplifying the investigation of cognitive alterations.

KEY MESSAGE

We examine the roles of hypo- and hyperglycemia, as well as the emerging role of glucocorticoids in the development of neuropsychological disorders. When specific mechanisms related to T1D are available, they are highlighted; otherwise, data and hypotheses applicable to both T1D and T2D are discussed.

The temporal dynamics of perceived stress and depression in college students: An ecological momentary assessment

Previous studies have implied that stress is a risk factor for depression, but relatively little is known about how healthy individuals' stress dynamically affects depression as a mood in daily life. Therefore, an ecological momentary assessment study was conducted among 141 college students to test the temporal dynamic effect of daily perceived stress on depression and the underlying mediating and moderating role of rumination. Perceived stress, state rumination, and depression were measured using self-compiled questionnaire three times a day over 12 days. Trait rumination was measured with the Nolen-Hoeksema Ruminative Response Scale. Hierarchical linear models with HLM 7.0 were adopted to examine the mediation and moderation effects. In the mediation model, the greater the daily perceived stress at time t, the higher the state rumination at time t + 1, and state rumination at t + 1 positively predicted college students' depression at t + 2. In the moderation model, trait rumination significantly facilitated perceived stress-induced depression. These results verified that daily perceived stress could affect college students' depression directly or indirectly through the critical mediating mechanism of state rumination, and this effect would be exacerbated with a higher level of trait rumination.

Effect of music-based interventions on anxiety and stress-related vital signs in patients undergoing cardiac catheterization: A systematic review and meta-analysis

OBJECTIVES

This work aimed to evaluate the effect of music-based intervention (MBI) on anxiety and stress-related vital signs (heart rate, respiratory rate and blood pressure) in patients undergoing cardiac catheterization.

DESIGN

A systematic review and meta-analysis.

METHODS

This systematic review and meta-analysis was conducted according to PRISMA guidelines. PubMed, Cochrane Library, Embase and CINAHL were systematically searched from inception to October 31, 2023. Two authors independently searched electronic databases, selected literature, extracted data and assessed the risk of bias according to the eligibility criteria. The Review Manager software (RevMan version 5.4.1) was used to perform meta-analysis.

RESULTS

Eleven randomized controlled trials (RCTs) with adult patients (n = 1204) (passive music therapy, 8 studies; passive music listening, 3 studies) were enrolled and brought into qualitative assessment. Nine of these RCTs (n = 868) were taken into quantitative analysis. Meta-analysis using the random-effects model revealed that the difference in the pre-post anxiety level in the music group was significantly greater than that in the control group. However, meta-analysis results for heart rate, respiratory rate, systolic blood pressure and diastolic blood pressure did not show significant differences.

CONCLUSION

The findings suggested that MBI had a significant effect on reducing anxiety in patients undergoing cardiac catheterization. However, the limited quantity and quality of included studies highlight the need for additional research to comprehensively analyze the influence of MBI on anxiety reduction in this patient population.

Diabetes and obesity: the role of stress in the development of cancer

Diabesity is a condition where an individual has both diabetes and obesity, which can lead to severe complications including cardiovascular disease, a leading cause of mortality. Recently, cancer has become a leading cause of excess hospitalizations, and both diabetes and obesity are associated with a higher risk of developing several types of cancer. In this review, we propose that chronic stress significantly increases this association. Managing diabetes and obesity is challenging as they both cause significant distress. The relationship between stress and cancer is interconnected, with anxiety and depression being common in cancer patients. Cancer diagnosis and treatment can cause lasting changes in the body's neuroendocrine system, with stress causing an excessive release of catecholamines and prostaglandins in patients undergoing cancer surgery, which promotes the spread of cancer to other parts of the body. Furthermore, stress could significantly increase the risk of cancer in patients with diabetes, obesity, or both.

Nociplastic pain mechanisms and toll-like receptors as promising targets for its management

ABSTRACT

Nociplastic pain, characterized by abnormal pain processing without an identifiable organic cause, affects a significant portion of the global population. Unfortunately, current pharmacological treatments for this condition often prove ineffective, prompting the need to explore new potential targets for inducing analgesic effects in patients with nociplastic pain. In this context, toll-like receptors (TLRs), known for their role in the immune response to infections, represent promising opportunities for pharmacological intervention because they play a relevant role in both the development and maintenance of pain. Although TLRs have been extensively studied in neuropathic and inflammatory pain, their specific contributions to nociplastic pain remain less clear, demanding further investigation. This review consolidates current evidence on the connection between TLRs and nociplastic pain, with a specific focus on prevalent conditions like fibromyalgia, stress-induced pain, sleep deprivation-related pain, and irritable bowel syndrome. In addition, we explore the association between nociplastic pain and psychiatric comorbidities, proposing that modulating TLRs can potentially alleviate both pain syndromes and related psychiatric disorders. Finally, we discuss the potential sex differences in TLR signaling, considering the higher prevalence of nociplastic pain among women. Altogether, this review aims to shed light on nociplastic pain, its underlying mechanisms, and its intriguing relationship with TLR signaling pathways, ultimately framing the potential therapeutic role of TLRs in addressing this challenging condition.

What the Acute Stress Response Suggests about Memory

Research suggests that stress has immediate and long-term effects on attention and memory. Rather than disrupting memory formation and consolidation, acute stress has been shown to shift attention processes resulting in a tradeoff between prioritized and nonprioritized information. Both arousal and stress result in cognitive and neurobiological shifts that often support memory formation. When an acute stressor occurs, it can distort immediate attentional focus, increasing processing for high-priority features while reducing processing for extraneous features. The downstream cognitive consequences for this shift in attention are better memory for some features and poorer memory for others when compared to conditions of low stress. However, individual differences (e.g., sex, age, basal stress response, and stress reactivity) all impact the relationship between the acute stress response and memory. Although acute stress generally benefits memory formation, we suggest that forgetting and later recovery of stressful memories can better be understood by examining factors that influence the subjective experience of stress and stress reactivity.

Observed child behavioral self-regulation and maternal supportive parenting are associated with dynamic physiological stress reactivity in preschoolers

This study sought to advance our understanding of how observed child self-regulation, parenting, and their interaction were associated with children's dynamic physiological stress reactivity indexed by respiratory sinus arrhythmia (RSA) reactivity trajectories. Participants were 85 three-year-old children (54% female) and their mothers oversampled for lower income, higher stressful life events, and higher child maltreatment risk. Child behavioral regulation, assessed as compliance and noncompliance, and maternal supportive parenting were observed during a challenging dyadic puzzle task. Results showed that child RSA exhibited quadratic change across the task on average, characterized by an expected initial decrease and subsequent recovery. Child behavioral regulation and its interaction with maternal supportive parenting were associated with interindividual differences in child RSA reactivity trajectories after controlling for child resting RSA. Children with higher compliance or lower noncompliance showed RSA decreases in response to task stressors but exhibited subsequent RSA recovery only when mothers displayed higher supportive parenting. Children with lower compliance or higher noncompliance displayed negligible RSA changes overall across the task, suggesting blunted or compromised RSA reactivity, regardless of supportive parenting levels. These findings demonstrate novel evidence that preschoolers' better behavioral regulation is related to their more adaptive physiological reactivity to stressors and that supportive parenting is needed to facilitate physiological recovery even in relatively better-regulated preschoolers. (PsycInfo Database Record (c) 2024 APA, all rights reserved).

Stress and Hypothalamic-Pituitary-Adrenal Axis: Effect on Prognosis of Dental Treatment

Stress is a process that activates neuronal, metabolic, and neuroendocrine mechanisms. The individual's response may be determined by variables such as genetic factors, environmental conditions, sex, and age, among others. These responses are critical for survival, and the involvement of the hypothalamic-pituitary-adrenal axis is necessary for adaptation, which through counter-regulatory mechanisms seeks to restore homeostasis. Dentists are aware that there are variations in people's response to treatment, and there are many patients in whom dental treatment generates an important source of stress, which in many cases leads to treatment avoidance behavior.

Combination of Metformin and Epigallocatechin-3-Gallate Lowers Cortisol, 11β-Hydroxysteroid Dehydrogenase Type 1, and Blood Glucose Levels in Sprague Dawley Rats with Obesity and Diabetes

Background

The combined effects of metformin and epigallocatechin-3-gallate (EGCG) on cortisol, 11β-hydroxysteroid dehydrogenase type 1 (11β-HSD1), and blood glucose levels have not been investigated. This study evaluated the effectiveness of combining EGCG with metformin in regulating those levels in a rat model of diet-induced diabetes and obesity.

Methods

Thirty diabetic and obese rats on a high-fat diet were treated daily for 28 days with EGCG (100 mg/kg of body weight/day), metformin (200 mg/kg of body weight/day), or both. Control groups comprised lean rats, untreated obese diabetic rats, and metformin-only-treated rats. Blood samples were collected to measure cortisol and fasting blood glucose (FBG) levels and liver tissue samples were examined for 11β-HSD1 levels.

Results

Rats receiving combination therapy had significantly reduced cortisol levels (from 36.70±15.13 to 31.25±7.10 ng/mL) compared with the untreated obese diabetic rats but not the rats receiving monotherapy. Rats receiving combination therapy and EGCG monotherapy had significantly lower 11β-HSD1 levels compared with the untreated obese diabetic rats (92.68±10.82 and 93.74±18.11 ng/L vs. 120.66±14.00 ng/L). Combination therapy and metformin monotherapy significantly reduced FBG levels (440.83±133.30 to 140.50±7.36 mg/dL and 480.67±86.32 to 214.17±102.78 mg/dL, respectively) by approximately 68.1% and 55.4% compared with rats receiving EGCG monotherapy and untreated obese diabetic rats.

Conclusion

Combining EGCG with metformin exhibited synergistic effects compared with monotherapy for managing diabetes, leading to improved outcomes in reduction of baseline cortisol levels along with reduction in 11β-HSD1 and blood glucose levels.

Sex-dependent effects of acute stress and alcohol exposure during adolescence on mRNA expression of brain signaling systems involved in reward and stress responses in young adult rats

BACKGROUND

Adolescent stress and alcohol exposure increase the risk of maladaptive behaviors and mental disorders in adulthood, with distinct sex-specific differences. Understanding the mechanisms underlying these early events is crucial for developing targeted prevention and treatment strategies.

METHODS

Male and female Wistar rats were exposed to acute restraint stress and intermittent alcohol during adolescence. We assessed lasting effects on plasma corticosterone (CORT) and adrenocorticotropic hormone (ACTH) levels, and mRNA expression of genes related to corticotropin releasing hormone (CRH), neuropeptide Y (NPY), corticoid, opioid, and arginine vasopressin systems in the amygdala and hypothalamus.

RESULTS

The main findings are as follows: (1) blood alcohol concentrations (BAC) increased after the final alcohol administration, but stressed males had lower BAC than non-stressed males; (2) Males gained significantly more weight than females; (3) Stressed females showed higher ACTH levels than non-stressed females, with no changes in males; (4) Stress increased CORT levels in males, while stressed, alcohol-treated females had lower CORT levels than non-stressed females; (5) CRH: Females had lower Crhr1 levels in the amygdala, while alcohol reduced Crhr2 levels in males but not females. Significant interactions among sex, stress, and alcohol were found in the hypothalamus, with distinct patterns between sexes; (6) NPY: In the amygdala, stress reduced Npy and Npy1r levels in males but increased them in females. Alcohol decreased Npy2r levels in males, with varied effects in females. Similar sex-specific patterns were observed in the hypothalamus; (7) Corticoid system: Stress and alcohol had complex, sex-dependent effects on Pomc, Nr3c1, and Nr3c2 in both brain regions; (8) Opioid receptors: Stress and alcohol blunted the elevated expression of Oprm1, Oprd1, and Oprk1 in the amygdala of males and the hypothalamus of females; (8) Vasopressin: Stress and alcohol interacted significantly to affect Avp and Avpr1a expression in the amygdala, with stronger effects in females. In the hypothalamus, alcohol increased Avp levels in females.

CONCLUSIONS

This study demonstrates that adolescent acute stress and alcohol exposure induce lasting, sex-specific alterations in systems involved in reward and stress responses. These findings emphasize the importance of considering sex differences in the prevention and management of HPA dysfunction and psychiatric disorders.

Is inflammatory change associated with psychological risk and resilience in high-risk military personnel?

INTRODUCTION

In military populations, the potential for under-reporting of Post-traumatic Stress Disorder (PTSD) symptoms and challenges in recognising early changes can make it difficult to detect an emerging disorder. However, early identification of PTSD symptoms would improve opportunities for intervention, and potentially reduce the likelihood of chronic mental health problems.

METHOD

This study explored if changes in levels of inflammation, measured by C reactive protein (CRP) and interleukin 6 (IL-6), were associated with the onset of psychological symptoms associated with PTSD. It also examined if changes in inflammation over time contributed to psychological risk and resilience, which was defined by psychological reactivity to deployment-related combat exposures. Participants were special forces personnel who completed psychological self-report questionnaires and had measures of CRP and IL-6 taken pre and post deployment. Regression analysis was used to examine how psychological symptoms predicted change in inflammation, and Analysis of Variance (ANOVA) were used to examine differences between identified subgroups.

RESULTS

Results identify this population as having high levels of combat and trauma exposures, with low-level psychological symptoms. The results also identified a decrease in CRP and an increase in IL-6 over time. A significant difference in inflammation was identified between subgroups (p<0.05). An association between inflammatory markers and subthreshold symptoms related to anger (p<0.01) and sleep (p<0.05) was also identified.

CONCLUSION

These preliminary findings suggest inflammatory markers may help to identify adaptive responses post deployment. In addition, low-level increases in inflammatory markers may be associated with subthreshold PTSD symptoms. These findings offer potential insights for prevention, early identification and treatment in military and veteran populations.

The relationship between cardiorespiratory fitness and inhibitory control following acute stress: An ERP study

Although the relationships among acute stress, cardiorespiratory fitness (CRF), and cognitive function have been examined, whether CRF is related to behavioral and neuroelectric indices of inhibitory control following acute stress remains unknown. The purpose of the current study was to investigate the combined influence of acute stress and CRF on inhibitory control. Participants, aged 20-30 years, were stratified into the Higher-Fit (n = 31) and the Lower-Fit (n = 32) groups, and completed a Stroop task following the modified Maastricht Acute Stress Test (MAST) in the stress condition and the sham-MAST in the non-stress condition, during which electroencephalography was recorded. Behavioral (i.e., response time and accuracy) and neuroelectric (N2 and P3b components of the event-related potential) outcomes of inhibitory control were obtained. While the Higher-Fit group demonstrated shorter response times and higher accuracy than the Lower-Fit group following both the MAST and the sham-MAST, they also exhibited selective benefits of acute stress on inhibitory control performance (i.e., decreased response times and diminished interference scores). CRF-dependent alterations in neuroelectric indices were also observed, with the Higher-Fit group displaying smaller N2 and greater P3b amplitudes than the Lower-Fit group following the sham-MAST, and increased N2 and attenuated P3b amplitudes following the MAST. Collectively, these findings not only confirm the positive relationship between CRF and inhibitory control but also provide novel insights into the potential influence of CRF on inhibitory control and associated neuroelectric activity following acute stress.

The caregiving role influences Suboptimal Health Status and psychological symptoms in unpaid carers

BACKGROUND

Suboptimal Health Status (SHS) is the physical state between health and disease. This study aimed to fill in the knowledge gap by investigating the prevalence of SHS and psychological symptoms among unpaid carers and to identify SHS-risk factors from the perspective of predictive, preventive and personalised medicine (PPPM).

METHODS

A cross-sectional study was conducted among 368 participants who were enrolled from Australia, including 203 unpaid carers as cases and 165 individuals from the general population as controls. SHS scores were measured using SHSQ-25 (Suboptimal Health Status Questionnaire-25), whilst psychological symptoms were measured by DASS-21 (Depression, Anxiety and Stress Scale-21). Chi-square was used to measure SHS and psychological symptom prevalence. Spearman correlation analysis was utilised to identify the relationship between SHSQ-25 and DASS-21 scores. Logistic regression analysis was used for multivariate analysis.

RESULTS

The prevalence of SHS in carers was 43.0% (98/203), significantly higher than the prevalence 12.7% (21/165) in the general population (p < 0.001). In addition, suboptimal health prevalence was higher in female carers (50.3%; 95/189) than females in the general population (12.4%; 18/145). Logistic regression showed that the caregiving role influenced SHS, with carers 6.4 times more likely to suffer from SHS than their non-caring counterparts (aOR = 6.400, 95% CI = 3.751-10.919).

CONCLUSIONS

Unpaid carers in Australia have a significantly higher prevalence of SHS than that in the general population and experience poorer health. The SHSQ-25 is a powerful tool that can be utilised to screen at-risk individuals to predict their risk of chronic disease development, an essential pillar for shifting the paradigm change from reactive medicine to that of predictive, preventive and personalised medicine (PPPM).

SUPPLEMENTARY INFORMATION

The online version contains supplementary material available at 10.1007/s13167-024-00370-8.

Transcranial direct current stimulation improves heart rate variability: A systematic review and meta-analysis

BACKGROUND

Heart rate variability (HRV) is a useful tool for evaluating cardiovascular autonomic nervous system (ANS) functions. This systematic review and meta-analysis examined the potential effects of transcranial direct current stimulation (tDCS) protocols on HRV parameters.

METHODS

This study acquired 97 comparisons from 24 qualified studies for data synthesis. Using standardized mean difference (SMD), individual and overall effect sizes were estimated to show differences in HRV variables between active tDCS and sham stimulation conditions. More positive effect size values indicated that active tDCS caused greater increases in HRV than sham stimulation. Furthermore, moderator variable analyses were performed to determine whether changes in HRV variables differed depending on (a) task types (physical stress versus psychological stress versus resting condition), (b) targeted brain regions, (c) stimulation polarity, (d) characteristics of participants, and (e) specific HRV variables. Finally, we used meta-regression analyses to determine whether different tDCS parameters (i.e., the number of tDCS sessions, stimulation duration, and density) were associated with changes in HRV patterns.

RESULTS

The random-effects model meta-analysis showed that tDCS protocols significantly improved HRV variables (SMD = 0.400; P < 0.001). Moreover, for increasing HRV during the physical stress task (SMD = 1.352; P = 0.001), anodal stimulation on the M1 was effective, while combined polarity stimulation on the PFC improved HRV during the psychological stress task (SMD = 0.550; P < 0.001) and resting condition (SMD = 0.192; P = 0.012). Additional moderator variables and meta-regression analyses failed to show that tDCS protocols had positive effects in certain conditions, such as different stimulus polarity, characteristics of participants, specific HRV variables, and tDCS parameters.

CONCLUSION

These findings tentatively suggest that using tDCS protocols to stimulate optimal targeted brain areas may be effective in improving HRV patterns potentially related to cardiovascular ANS functions.

Pain pathophysiology and pharmacology of cattle: how improved understanding can enhance pain prevention, mitigation, and welfare

Globally, humans rely on cattle for food production; however, there is rising societal concern surrounding the welfare of farm animals. From a young age, cattle raised for dairy and beef production experience pain caused by routine management procedures and common disease conditions. The fundamental mechanisms, nociceptive pathways, and central nervous system structures required for pain perception are highly conserved among mammalian species. However, there are limitations to a comparative approach to pain assessment due to interspecies differences in the expression of pain. The stoicism of prey species may impede pain identification and lead to the assumption that cattle lack pain sensitivity. This highlights the importance of establishing validated bovine-specific indicators of pain-a prerequisite for evidence-based pain assessment and mitigation. Our first objective is to provide an overview of pain pathophysiology to illustrate the importance of targeted analgesia in livestock medicine and the negative welfare outcomes associated with unmitigated pain. This is followed by a review of available analgesics, the regulations governing their use, and barriers to implementation of on-farm pain management. We then investigate the current research undertaken to evaluate the pain response in cattle-a critical aspect of the drug approval process. With an emphasis on emerging research in animal cognition and pain pathology, we conclude by discussing the significant influence that pain has on cattle welfare and areas where further research and modified practices are indicated.

Preventing social defeat stress-induced behavioural and neurochemical alterations by repeated treatment with a mix of Centella asiatica, Echinacea purpurea and Zingiber officinale standardized extracts

Background: Prolonged exposure to stress is a risk factor for the onset of several disorders. Modern life is burdened by a pervasive prevalence of stress, which represents a major societal challenge requiring new therapeutic strategies. In this context, botanical drug-based therapies can have a paramount importance. Methods: Here we studied the preventive effects of a repeated treatment (p.o. daily, 3 weeks) with a combination of Centella asiatica (200 mg/kg), Echinacea purpurea (20 mg/kg) and Zingiber officinale (150 mg/kg) standardized extracts, on the chronic social defeat stress (CSDS) deleterious outcomes. After 10 days of CSDS exposure, male mice' performances were evaluated in paradigms relevant for social (social interaction test), emotional (tail suspension test), cognitive (novel object recognition) domains as well as for pain perception (cold plate and von Frey tests) and motor skills (rotarod). Mice were then sacrificed, the spinal cords, hippocampi and frontal cortices dissected and processed for RT-PCR analysis. Results: Extracts mix treatment prevented stress-induced social aversion, memory impairment, mechanical and thermal allodynia and reduced behavioural despair independently of stress exposure. The treatment stimulated hippocampal and cortical BDNF and TrkB mRNA levels and counteracted stress-induced alterations in pro- (TNF-α, IL-1β and IL-6) and anti-inflammatory (IL4, IL10) cytokines expression in the same areas. It also modulated expression of pain related genes (GFAP and Slc1a3) in the spinal cord. Conclusion: The treatment with the extracts mix obtained from C. asiatica, E. purpurea and Z. officinale may represent a promising strategy to promote resilience and prevent the deleterious effects induced by extended exposure to psychosocial stress.

Liver-based inter-organ communication: A disease perspective

Inter-organ communication through hormones, cytokines and extracellular vesicles (EVs) has emerged to contribute to the physiological states and pathological processes of the human body. Notably, the liver coordinates multiple tissues and organs to maintain homeostasis and maximize energy utilization, with the underlying mechanisms being unraveled in recent studies. Particularly, liver-derived EVs have been found to play a key role in regulating health and disease. As an endocrine organ, the liver has also been found to perform functions via the secretion of hepatokines. Investigating the multi-organ communication centered on the liver, especially in the manner of EVs and hepatokines, is of great importance to the diagnosis and treatment of liver-related diseases. This review summarizes the crosstalk between the liver and distant organs, including the brain, the bone, the adipose tissue and the intestine in noticeable situations. The discussion of these contents will add to a new dimension of organismal homeostasis and shed light on novel theranostics of pathologies.

11β-Hydroxysteroid dehydrogenase type 2 may mediate the stress-specific effects of cortisol on brain cell proliferation in adult zebrafish (Danio rerio)

Stress-induced increases in cortisol can stimulate or inhibit brain cell proliferation, but the mechanisms behind these opposing effects are unknown. We tested the hypothesis that 11β-hydroxysteroid dehydrogenase type 2 (Hsd11b2), a glucocorticoid-inactivating enzyme expressed in neurogenic regions of the adult zebrafish brain, mitigates cortisol-induced changes to brain cell proliferation, using one of three stress regimes: a single 1 min air exposure (acute stress), two air exposures spaced 24 h apart (repeat acute stress) or social subordination (chronic stress). Plasma cortisol was significantly elevated 15 min after air exposure and recovered within 24 h after acute and repeat acute stress, whereas subordinate fish exhibited significant and sustained elevations relative to dominant fish for 24 h. Following acute stress, brain hsd11b2 transcript abundance was elevated up to 6 h after a single air exposure but was unchanged by repeat acute stress or social subordination. A sustained increase in brain Hsd11b2 protein levels occurred after acute stress, but not after repeat or chronic stress. Following acute and repeat acute stress, brain pcna transcript abundance (a marker of cell proliferation) exhibited a prolonged elevation, but was unaffected by social subordination. Interestingly, the number of telencephalic BrdU+ cells increased in fish after a single air exposure but was unchanged by repeat acute stress. Following acute and repeat acute stress, fish expressed lower brain glucocorticoid and mineralocorticoid receptor (gr and mr) transcript abundance while subordinate fish exhibited no changes. Taken together, these results demonstrate stressor-specific regulation of Hsd11b2 in the zebrafish brain that could modulate rates of cortisol catabolism contributing to observed differences in brain cell proliferation.

Aggression Unleashed: Neural Circuits from Scent to Brain

Aggression is a fundamental behavior with essential roles in dominance assertion, resource acquisition, and self-defense across the animal kingdom. However, dysregulation of the aggression circuitry can have severe consequences in humans, leading to economic, emotional, and societal burdens. Previous inconsistencies in aggression research have been due to limitations in techniques for studying these neurons at a high spatial resolution, resulting in an incomplete understanding of the neural mechanisms underlying aggression. Recent advancements in optogenetics, pharmacogenetics, single-cell RNA sequencing, and in vivo electrophysiology have provided new insights into this complex circuitry. This review aims to explore the aggression-provoking stimuli and their detection in rodents, particularly through the olfactory systems. Additionally, we will examine the core regions associated with aggression, their interactions, and their connection with the prefrontal cortex. We will also discuss the significance of top-down cognitive control systems in regulating atypical expressions of aggressive behavior. While the focus will primarily be on rodent circuitry, we will briefly touch upon the modulation of aggression in humans through the prefrontal cortex and discuss emerging therapeutic interventions that may benefit individuals with aggression disorders. This comprehensive understanding of the neural substrates of aggression will pave the way for the development of novel therapeutic strategies and clinical interventions. This approach contrasts with the broader perspective on neural mechanisms of aggression across species, aiming for a more focused analysis of specific pathways and their implications for therapeutic interventions.

Insecure Attachment, Oxytocinergic System and C-Tactile Fibers: An Integrative and Translational Pathophysiological Model of Fibromyalgia and Central Sensitivity Syndromes

Although the pathophysiology of fibromyalgia syndrome has been better understood in recent decades, a unified model of its pathogenesis and an effective therapeutic approach are still far from being realized. The main aim of this article will be to delve into the fundamental mechanisms of the pathophysiology of fibromyalgia conceptualized as stress intolerance syndrome. Using the biopsychosocial model of chronic pain syndromes, we will describe the potential role of the attachment system, C-tactile fibers, and oxytocinergic system dysfunction in the pathophysiology of fibromyalgia syndrome and other central sensitivity syndromes. At the end of the article, the therapeutic implications of this new global and translational pathophysiological model will be briefly discussed.

Squamous papilloma involving the mandible: A case report and descriptive literature review

Squamous papilloma is a benign neoplasm that originates from the stratified squamous epithelium of the mucous membrane. Its principal etiological factor is human papillomavirus infection, with a predilection for manifesting within the oral cavity. Squamous papilloma predominantly affects regions on the palate, cheeks, lips and tongue. However, to the best of our knowledge, the occurrence of squamous papilloma within the confines of the mandible remains unreported hitherto. The present report documents a case of squamous papilloma involving the mandible who was managed at the First Affiliated Hospital of Sun Yat-sen University (Guangzhou, China) in January 2023. The patient underwent a series of recurrent jaw inflammations, manifesting with malignant imaging characteristics. Subsequent pathological analysis confirmed a diagnosis of papilloma in the jaw. The present report highlights the pivotal role of prolonged inflammation in the genesis of jaw squamous papilloma, prompting avenues for further investigation, including the potential of inflammation to induce aberrant cell growth, mediate cell interactions, orchestrate cytokine actions and influence stress mediators. In addition, the current study posits a plausible connection between persistent inflammation, compromised epithelial integrity and an increased likelihood of head and neck papilloma, particularly concerning human papillomavirus infection. This article delineates the clinical attributes of the uncommon manifestations of jaw papilloma and delves into the associated mechanisms, thereby contributing to an enhanced comprehension of jaw disorders. This comprehensive insight equips clinicians with a heightened knowledge base for more precise diagnosis and treatment of analogous cases.

Defining and distinguishing early life stress, trauma, adversity, toxic and chronic stress and allostatic load: a descriptive review

AIMS

Various concepts are used to study the impact of stress on childhood development. These concepts are often used inconsistently or interchangeably. Our main objectives were to determine how selected stress concepts (chronic stress, toxic stress, allostatic load, early life stress, childhood adversity, childhood trauma and adverse childhood experiences; ACEs) are defined, operationalized and described, and to provide a theoretical context to aid the choice for a preferred concept in public health research.

METHODS

For this descriptive review, we systematically searched for literature published before 4 August 2021, on PubMed, Embase and PsycInfo. Two independent reviewers included studies. Exclusion criteria were: no systematic review, not peer reviewed, not published in English, selected stress concepts were no predetermined variable or a substantial topic in the discussion, full text was unobtainable or study described non-human or non-childhood populations. Data extraction forms were used. Descriptives were gathered, publication fields were identified through Journal Citation Reports categories, and verbatim descriptions were ordered in text and Venn diagrams.

RESULTS

Of 264 screened studies, 124 were included. ACEs, childhood adversity and childhood trauma were used most. ACEs were the main concept used most frequently (47.6%). A total of 11 of 14 public and environmental health journals used ACEs. All concepts refer to prolonged, repeated, interpersonal stress from 0 to 18 years, that can alter physiological systems. Four concepts were stressor oriented, two concepts focused on stress response and effect and one on the state of challenged homeostasis.

CONCLUSIONS

ACEs seem most fitting for public health setting, due to their operationalizability, large set of core experiences and widespread use.

Exploring the effect of prolonged fasting on kynurenine pathway metabolites and stress markers in healthy male individuals

BACKGROUND/OBJECTIVES

Prolonged fasting triggers a stress response within the human body. Our objective was to investigate the impact of prolonged fasting, in conjunction with stress, on kynurenine pathway metabolites.

SUBJECTS/METHODS

Healthy males were divided into fasting group (zero-calorie-restriction) for 6 days (FAST, n = 14), and control group (CON, n = 10). Blood and saliva samples were collected at baseline, Day 2, Day 4, Day 6 during fasting period, and 1 week after resuming regular diet. Plasma levels of kynurenine pathway metabolites were measured using ultra-performance liquid chromatography-mass spectrometry (UPLC-MS/MS). Plasma and salivary samples were analyzed for stress markers.

RESULTS

A pronounced activation of the kynurenine pathway in individuals on FAST trial was revealed. Concentrations of picolinic acid (PIC), kynurenic acid (KYNA) and 3-hydroxykynurenine (3-HK) were significantly increased, with peak levels observed on Day 6 (P < 0.0001). Conversely, concentrations of tryptophan (TRP) and quinolinic acid (QUIN) decreased (P < 0.0001), while kynurenine (KYN) and nicotinamide (NAM) levels remained stable. Cortisol and noradrenaline concentrations remained unchanged. However, adrenaline levels significantly increased on Day 4 within FAST compared to CON (P = 0.005). Notably, all deviations in kynurenine pathway metabolite levels returned to baseline values upon resuming regular diet following the 6-day fasting regimen, even when weight and BMI parameters were not restored.

CONCLUSIONS

Extended fasting over 6 days induces the kynurenine pathway and has minimal effects on stress markers. Restoration of metabolite concentrations upon regular feeding implies rapid adaptation of the kynurenine pathway synthetic enzymes to maintain homeostasis when faced with perturbations.

The Causal Effects between Mood Swings and Gastrointestinal Diseases: A Mendelian Randomization Study

Background

Numerous studies have examined the links between mental disorders such as depression and bipolar disorder, and gastrointestinal (GI) diseases. However, few studies have investigated the link between mood swings and GI diseases. Given the impact of mood swings on various conditions and the growing comprehension of the gut-brain axis, this study aims to explore their causal relationship using Mendelian randomization (MR) methods.

Methods

Single-nucleotide polymorphisms (SNPs) associated with mood swings were obtained from a recent study. SNPs associated with GI diseases were identified from the FinnGen project. We conducted two-sample bidirectional MR analyses using three methods, primarily the inverse variance weighting (IVW) method. Furthermore, we performed sensitivity analyses and false discovery rate (FDR) analysis to validate the accuracy and robustness of the results.

Results

Bidirectional MR analysis revealed significant causal effects between mood swings and GI diseases according to the IVW method (odds ratio (OR): 1.213; 95% confidence interval (CI): 1.118-1.316; P = 3.490e-6; P FDR = 8.730e-5). Mood swings were linked to an increased risk for 11 of 24 diseases, including five upper GI diseases (gastroesophageal reflux disease (GERD), acute gastritis, gastroduodenal ulcer, duodenal ulcer, and functional dyspepsia), two lower GI diseases (diverticular disease of the intestine and irritable bowel syndrome (IBS)) and four hepatobiliary and pancreatic diseases (nonalcoholic fatty liver disease (NAFLD), chronic pancreatitis, acute pancreatitis, and pancreatic cancer). Inverse MR analysis showed no causal relationship between 24 GI diseases and mood swings.

Conclusions

This comprehensive MR analysis suggests that genetically predicted mood swings may be a risk factor in the development of GI diseases. Interventions for mood swings may help to treat GI diseases.

Heart rate response to cognitive load as a marker of depression and increased anxiety

Introduction

Understanding the interplay between cardiovascular parameters, cognitive stress induced by increasing load, and mental well-being is vital for the development of integrated health strategies today. By monitoring physiological signals like electrocardiogram (ECG) and photoplethysmogram (PPG) in real time, researchers can discover how cognitive tasks influence both cardiovascular and mental health. Cardiac biomarkers resulting from cognitive strain act as indicators of autonomic nervous system function, potentially reflecting conditions related to heart and mental health, including depression and anxiety. The purpose of this study is to investigate how cognitive load affects ECG and PPG measurements and whether these can signal early cardiovascular changes during depression and anxiety disorders.

Methods

Ninety participants aged 18 to 45 years, ranging from symptom-free individuals to those with diverse psychological conditions, were assessed using psychological questionnaires and anamnesis. ECG and PPG monitoring were conducted as volunteers engaged in a cognitive 1-back task consisting of two separate blocks, each with six progressively challenging levels. The participants' responses were analyzed to correlate physiological and psychological data with cognitive stressors and outcomes.

Results

The study confirmed a notable interdependence between anxiety and depression, and cardiovascular responses. Task accuracy decreased with increased task difficulty. A strong relationship between PPG-measured heart rate and markers of depression and trait anxiety was observed. Increasing task difficulty corresponded to an increase in heart rate, linked with elevated levels of depression and trait anxiety. A strong relationship between ECG-measured heart rate and anxiety attacks was observed. Increasing task difficulty corresponded to an increase in heart rate, linked with elevated levels of anxiety attacks, although this association decreased under more challenging conditions.

Discussion

The findings underscore the predictive importance of ECG and PPG heart rate parameters in mental health assessment, particularly depression and anxiety under cognitive stress induced by increasing load. We discuss mechanisms of sympathetic activation explaining these differences. Our research outcomes have implications for clinical assessments and wearable device algorithms for more precise, personalized mental health diagnostics.

Effects of Acute Mental Stress on Choroidal Thickness

Purpose: Previous studies have indicated an association between education and myopia, suggesting that numerous stress events during the educational process may influence eye health. This study aimed to investigate the impact of mental stress induced by mental arithmetic (MA) on choroidal thickness (CT). Methods: This study included 33 participants aged between 19 and 29 years. Swept-source optical coherence tomography (SS-OCT) was used to capture images of the posterior segment of the left eye during baseline and MA to assess changes in the CT. After denoising and compensation, the baseline images and MA images that had been rigidly registered and resampled to the baseline images were segmented using a deep learning-based method. Based on the segmentation results, the CT within the regions of 1 mm and 3 mm diameter centered at the lowest point of the fovea was calculated. Results: Significant increases were observed in both CT1mm and CT3mm during MA, with mean changes of 2.742 ± 7.098 μm (p = 0.034) and 3.326 ± 6.143 μm (p < 0.001), respectively. Conclusions: Thickening of the choroid has been observed during acute mental stress. We speculate that long-term or chronic mental stress could have a potential adverse impact on myopia progression.

Early Life Stress Influences Oxidative Stress Enzyme Activities in Liver, Heart, Kidney, Suprarenal Glands, and Pancreas in Male and Female Rat Pups

Early life stress (ELS) is a risk factor for the development of chronic diseases resulting from functional alterations of organs in the cardiorespiratory and renal systems. This work studied the changes in oxidative stress enzyme activities (EAs) of SOD, CAT, GPX, GR, GST, NOS, MDA, and FRAP in different organs (heart, liver, kidney, adrenal glands (AGs), and pancreas) of male and female Sprague-Dawley rat pups on postnatal day (PN) 15, immediately after basal and acute or chronic stress conditions were accomplished, as follows: basal control (BC; undisturbed maternal pups care), stress control (SC; 3 h maternal separation on PN15), basal maternal separation (BMS; daily 3 h maternal separation on PN 1-14), and stress maternal separation (SMS; daily 3 h maternal separation on PN 1-14 and 3 h maternal separation on PN15). Acute or long-term stress resulted in overall oxidative stress, increase in EA, and reduced antioxidant capacity in these organs. Some different response patterns, due to precedent SMS, were observed in specific organs, especially in the AGs. Acute stress exposure increases the EA, but chronic stress generates a response in the antioxidant system in some of the organs studied and is damped in response to a further challenge.

The Relationship between Diet, Depression, and Alzheimer's Disease: A Narrative Review

PURPOSE OF REVIEW

This narrative review evaluates the role of diet in the relationship between depression and Alzheimer's disease (AD).

RECENT FINDINGS

AD and depression are often comorbid, and depression appears to independently increase the future risk of AD. Evidence suggests diet influences the risk of both conditions directly and indirectly. Diet impacts neurochemical and biological processes that may affect the development and progression of depression and cognitive dysfunction. The dietary components offering the greatest protection against depression and AD are yet to be determined. Current evidence highlights the importance of polyphenolic compounds, folate, B vitamins, and polyunsaturated fatty acids, along with adherence to dietary patterns like the Mediterranean diet, which includes multiple beneficial dietary factors.

SUMMARY

The investigation of dietary factors in the prevention of depression and AD is a comparatively young field of research. Comprehensive highly characterised longitudinal datasets and advanced analytical approaches are required to further examine the complex relationship between diet, depression, and AD. There is a critical need for more research in this area to develop effective preventive strategies aimed at maintaining mental and physical health with advancing age.

Through the Lens of Movement-Evoked Pain: A Theoretical Framework of the "Pain-Movement Interface" to Guide Research and Clinical Care for Musculoskeletal Pain Conditions

Over 120 million Americans report experiencing pain in the past 3 months. Among these individuals, 50 million report chronic pain and 17 million report pain that limits daily life or work activities on most days (ie, high-impact chronic pain). Musculoskeletal pain conditions in particular are a major contributor to global disability, health care costs, and poor quality of life. Movement-evoked pain (MEP) is an important and distinct component of the musculoskeletal pain experience and represents an emerging area of study in pain and rehabilitation fields. This focus article proposes the "Pain-Movement Interface" as a theoretical framework of MEP that highlights the interface between MEP, pain interference, and activity engagement. The goal of the framework is to expand knowledge about MEP by guiding scientific inquiry into MEP-specific pathways to disability, high-risk clinical phenotypes, and underlying individual influences that may serve as treatment targets. This framework reinforces the dynamic nature of MEP within the context of activity engagement, participation in life and social roles, and the broader pain experience. Recommendations for MEP evaluation, encompassing the spectrum from high standardization to high patient specificity, and MEP-targeted treatments are provided. Overall, the proposed framework and recommendations reflect the current state of science in this emerging area of study and are intended to support future efforts to optimize musculoskeletal pain management and enhance patient outcomes. PERSPECTIVE: Movement-evoked pain (MEP) is a distinct component of the musculoskeletal pain experience and emerging research area. This article introduces the "Pain-Movement Interface" as a theoretical framework of MEP, highlighting the interface between MEP, pain interference, and activity engagement. Evaluating and treating MEP could improve rehabilitation approaches and enhance patient outcomes.

An investigation on the role of oxytocin in chronic neuropathic pain in a Wistar rat model

Introduction Chemotherapy-induced peripheral neuropathy (CIPN) is a dose-limiting side effect with ineffective preventative and curative treatment. Currently, only Duloxetine has been recommended as effective treatment for CIPN, which has shown individual-dependent, short-term analgesic effects, with limiting adverse effects and poor bioavailability. The neuropeptide, oxytocin, may offer significant analgesic and anxiolytic potential, as it exerts central and peripheral attenuating effects on nociception. However, it is unknown whether the intervention administered in a model of CIPN is an effective therapeutic alternative or adjuvant. Materials and Methods The intervention was divided into two phases. Phase 1 aimed to induce CIPN in adult Wistar rats using the chemotherapeutic agent Paclitaxel. Mechanical (electronic von Frey filament) and thermal (acetone evaporation test and Hargreaves test) hypersensitivity testing were used to evaluate changes due to the neuropathic induction. Phase 2 consisted of a 14-day intervention period with saline (o.g.), duloextine (o.g.), or oxytocin (i.n.) administered as treatment. Following the intervention, anxiety-like behaviour was assessed using the elevated plus maze (EPM) and light-dark box protocols. Analysis of peripheral plasma corticosterone, peripheral plasma oxytocin, and hypothalamic oxytocin concentrations were assessed using ELISA assays. Results The findings showed that we were able to successfully establish a model of chemotherapy-induced peripheral neuropathy during Phase 1, determined by the increase in mechanical and thermal nociceptive responses following Paclitaxel administration. Furthermore, the animals treated with oxytocin displayed a significant improvement in mechanical sensitivity over the intervention phase, indicative of an improvement in nociceptive sensitivity in the presence of neuropathic pain. Animals that received Paclitaxel and treated with oxytocin also displayed significantly greater explorative behaviour during the EPM, indicative of a reduced presence of anxiety-like behaviour. Conclusion Our results support the hypothesis that intranasally administered oxytocin may augment the analgesic and anxiolytic effects of duloxetine in a chemotherapy induced peripheral neuropathy model in a Wistar rat. Future studies should consider administering the treatments in combination to observe the potential synergistic effects.

Epigenetic associations in HPA axis genes related to bronchopulmonary dysplasia and antenatal steroids

BACKGROUND

Bronchopulmonary dysplasia (BPD), a common morbidity among very preterm infants, is associated with chronic disease and neurodevelopmental impairments. A hypothesized mechanism for these outcomes lies in altered glucocorticoid (GC) activity. We hypothesized that BPD and its treatments may result in epigenetic differences in the hypothalamic-pituitary-adrenal (HPA) axis, which is modulated by GC, and could be ascertained using an established GC risk score and DNA methylation (DNAm) of HPA axis genes.

METHODS

DNAm was quantified from buccal tissue (ECHO-NOVI) and from neonatal blood spots (ELGAN ECHO) via the EPIC microarray. Prenatal maternal characteristics, pregnancy complication, and neonatal medical complication data were collected from medical record review and maternal interviews.

RESULTS

The GC score was not associated with steroid exposure or BPD. However, six HPA genes involved in stress response regulation demonstrated differential methylation with antenatal steroid exposure; two CpGs within FKBP5 and POMC were differentially methylated with BPD severity. These findings were sex-specific in both cohorts; males had greater magnitude of differential methylation within these genes.

CONCLUSIONS

These findings suggest that BPD severity and antenatal steroids are associated with DNAm at some HPA genes in very preterm infants and the effects appear to be sex-, tissue-, and age-specific.

IMPACT

This study addresses bronchopulmonary dysplasia (BPD), an important health outcome among preterm neonates, and interrogates a commonly studied pathway, the hypothalamic-pituitary-adrenal (HPA) axis. The combination of BPD, the HPA axis, and epigenetic markers has not been previously reported. In this study, we found that BPD itself was not associated with epigenetic responses in the HPA axis in infants born very preterm; however, antenatal treatment with steroids was associated with epigenetic responses.

Terminalia chebula attenuates restraint stress-induced memory impairment and synaptic loss in the dentate gyrus of the hippocampus and the basolateral and central nuclei of the amygdala by inhibiting oxidative damage

Chronic restraint stress induces cognitive abnormalities through changes in synapses and oxidant levels in the amygdala and hippocampus. Given the neuroprotective effects of fruit of Terminalia chebula (Halileh) in different experimental models, the present investigation aimed to address whether Terminalia chebula is able to reduce chronic restraint stress-induced behavioral, synaptic and oxidant markers in the rat model. Thirty-two male Wistar rats were randomly divided into four groups as follows: control (did not receive any treatment and were not exposed to stress), stress (restraint stress for 2 h a day for 14 consecutive days), Terminalia chebula (received 200 mg/kg hydroalcoholic extract of Terminalia chebula), and stress + Terminalia chebula groups (received 200 mg/kg extract of Terminalia chebula twenty minutes before stress) (n = 8 in each group). We used the shuttle box test to assess learning and memory, Golgi-Cox staining to examine dendritic spine density in the dentate gyrus region of the hippocampus and the basolateral and central nuclei of the amygdala, and total antioxidant capacity (TAC) and total oxidant status (TOS) in the brain. The shuttle box test results demonstrated that Terminalia chebula treatment had a profound positive effect on memory parameters, including step-through latency (STL) and time spent in the dark room, when compared to the stress group. Daily oral treatment with Terminalia chebula effectively suppressed the loss of neural spine density in the dentate gyrus region of the hippocampus and the basolateral and central nuclei of the amygdala caused by chronic restraint stress, as demonstrated by Golgi-Cox staining. Additionally, the results indicate that Terminalia chebula significantly reduced the TOS and increased TAC in the brain compared to the stress group. In conclusion, our results suggest that Terminalia chebula improved memory impairment and synaptic loss in the dentate gyrus of the hippocampus and the basolateral and central nuclei of the amygdala induced by restraint stress via inhibiting oxidative damage.

The Relationship Between Hyperalbuminemia and Unscheduled Medical Visits: A Retrospective Cohort Study

Introduction Hyperalbuminemia, defined as elevated serum albumin levels, may influence healthcare utilization, particularly unscheduled medical visits. The sympathetic nervous system (SNS) regulates serum albumin, which is crucial for maintaining oncotic pressure and substance transport. SNS instability, linked to chronic diseases, can impact albumin levels. This study investigates the association between hyperalbuminemia and unscheduled medical visits in community hospital outpatient departments, aiming to establish its potential as a predictor of healthcare utilization. Methods This retrospective cohort study utilized electronic medical records from Unnan City Hospital, Japan, from September 2021 to August 2023. Participants were over 15 years old and had albumin data available, excluding those with acute albumin conditions. The case group consisted of 321 hyperalbuminemia patients (serum albumin ≥ 5 g/dL), matched monthly with 16 controls. Data on demographics, chronic diseases, and unscheduled medical visits were collected. Multivariate logistic regression analyzed the association between hyperalbuminemia and unscheduled medical visits. Results Among 716 participants, the hyperalbuminemia group (mean age 59.13 years) was younger than the non-hyperalbuminemia group (mean age 74.36 years). Hyperalbuminemia patients had a higher BMI, pulse rate, and prevalence of diabetes, dyslipidemia, and brain stroke. Significant associations were found between hyperalbuminemia and unscheduled medical visits (OR 2.35, 95% CI 1.56-3.53, p < 0.001), age, BMI, pulse rate, and brain stroke. Conclusion Hyperalbuminemia is significantly associated with increased unscheduled medical visits in rural outpatient settings. Routine serum albumin assessments can aid in risk stratification and personalized care, potentially reducing acute healthcare needs. Future research should explore underlying mechanisms and broader populations to enhance clinical applications.