Understanding Emotions: Origins and Roles of the Amygdala

Alterations in magnetic susceptibility correlate with higher cerebral blood flow in the right amygdala of patients with major depressive disorder

BACKGROUND

The amygdala plays a crucial role in emotion processing and is a key target for understanding the mechanisms underlying major depressive disorder (MDD). This study aimed to investigate the magnetic susceptibility of the amygdala in MDD and examine its association with structural and cerebral blood flow (CBF) changes.

METHODS

A total of 158 individuals were included in the study, comprising 86 patients with MDD and 72 healthy controls. Depression severity was assessed using Hamilton Depression Rating Scale. Quantitative susceptibility mapping (QSM), T1-weighted, and arterial spin labeling scans were conducted to measure amygdala magnetic susceptibility, volume, and CBF, respectively. Group differences were compared, and associations between susceptibility, volume, and CBF were examined.

RESULTS

The median susceptibility of the amygdala was significantly higher in MDD patients than in controls (all p < 0.01). In the MDD group, increased QSM value in the right amygdala was associated with higher CBF (r = 0.28, p = 0.01), whereas no significant correlation was found between QSM value and volume (p = 0.76). Increased QSM value in the right amygdala was associated with worse depressed mood (r = 0.30, p < 0.01).

LIMITATION

Retrospective cross-sectional study conducted at a single center.

CONCLUSION

The magnetic susceptibility of the amygdala was higher in MDD patients with than in controls. QSM changes in the right amygdala correlated with increased CBF and worse depressed mood, indicating both microstructural and functional alterations. Our results encourage further use of the QSM technique in the elucidation of MDD pathophysiology.

Sex-specific alterations in emotional behavior and neurotransmitter systems in LPA1 receptor-deficient mice

Lysophosphatidic acid (LPA) and the endocannabinoid system (ECS) are critical lipid signaling pathways involved in emotional regulation and behavior. Despite their interconnected roles and shared metabolic pathways, the specific contributions of LPA signaling through the LPA1 receptor to stress-related disorders remain poorly understood. This study investigates the effects of LPA1 receptor deficiency on emotional behavior and neurotransmitter-related gene expression, with a focus on sex-specific differences, using maLPA1-null mice of both sexes. We hypothesized LPA1 receptor loss disrupts the interplay between LPA and the endocannabinoid 2-arachidonoylglycerol (2-AG) signaling, resulting in distinct behavioral and molecular alterations. maLPA1-null mice exhibited increased anxiety-like behaviors and altered stress-coping responses compared to wild-type counterparts, with more pronounced effects observed in females. Female mice also displayed higher corticosterone levels, though no genotype-related differences were observed. Plasma analyses revealed elevated LPA levels in maLPA1-null mice, suggesting a compensatory mechanism, and reduced 2-AG levels, indicating impaired ECS signaling. Gene expression profiling in the amygdala and medial prefrontal cortex showed significant alterations in the gene expression of key components of LPA and 2-AG signaling pathways, as well as neuropeptide systems such as corticotropin-releasing hormone (CRH) and neuropeptide Y (NPY). Glutamatergic signaling components also exhibited sex-specific variations. These findings suggest that LPA1 receptor deficiency impacts behavioral response and disrupts sex-specific neurotransmitter signaling, emphasizing the importance of LPA-ECS crosstalk in emotional regulation. This study provides insights into the molecular mechanisms underlying stress-related disorders such as depression and anxiety, which may inform the development of sex-specific therapeutic approaches.

From valence encoding to motivated behavior: A focus on the nucleus accumbens circuitry

How do our brains determine whether something is good or bad? The brain's ability to evaluate stimuli as positive or negative - by attributing valence - is fundamental to survival and decision-making. Different brain regions have been associated with valence encoding, including the nucleus accumbens (NAc). The NAc is predominantly composed of GABAergic medium spiny neurons (MSNs), which segregate into two distinct populations based on their dopamine receptor expression: D1-receptor-expressing (D1-MSNs) and D2-receptor-expressing neurons (D2-MSNs). Classical models propose a binary functional role, where D1-MSNs exclusively mediated reward and positive valence, while D2-MSNs processed aversion and negative valence. However, we now recognize that NAc MSN subpopulations operate in a more complex manner than previously thought, often working cooperatively rather than antagonistically in valence-related behaviors. This review synthesizes our current knowledge of valence-encoding neurocircuitry, with emphasis on the NAc. We examine electrophysiological, calcium imaging, optogenetic, chemogenetic and pharmacological studies detailing the contribution of NAc medium spiny neurons for rewarding and aversive responses. Finally, we explore emerging technical innovations that promise to advance our understanding of how the mammalian brain encodes valence and translates it into behavior.

Brain network alterations in fragile X syndrome

Fragile X syndrome (FXS), caused by FMR1 gene mutations, leads to widespread brain alterations significantly impacting cognition and behaviour. Recent advances have provided a deeper understanding of the neural substrates of FXS. This review provides a comprehensive overview of the current knowledge of neuronal network alterations in FXS. We highlight imaging studies that demonstrate network-level disruptions within resting-state networks, including the default mode network, frontoparietal network, salience network, and basal ganglia network, linked to cognitive, emotional and motor deficits in FXS. Next, we link dysregulated network activity in FXS to molecular studies showing neurometabolic imbalances, particularly in GABAergic and glutamatergic systems. Additionally, gene-brain-behavior correlations are explored with gene expression maps to illustrate regional FMR1 expression patterns tied to clinical symptoms. A graph analysis and meta-analytic mapping further link these dysfunctional networks to the specific symptoms of FXS. We conclude by highlighting gaps in the literature, including the need for greater global collaboration, inclusion of underrepresented populations, and consideration of transdiagnostic effects in future research to advance neuroimaging and therapeutic approaches for FXS.

Exploratory structural neuroimaging examination of impulsivity in severe alcohol use disorder: Persistent implication of the ventral striatum

BACKGROUND

While Alcohol Use Disorder (AUD) is frequently associated with impulsivity, its structural brain substrates are still poorly defined. The triadic model of addiction postulates that impulsive behavior is regulated by an amygdalo-striatal impulsive subcomponent, a prefrontal and cerebellar reflective subcomponent, and an insular regulatory subcomponent. The objective of this study was thus to examine the relationships between self-evaluated impulsivity and structural brain abnormalities in patients with severe AUD (sAUD) using the triadic model as a theoretical framework.

METHODS

Twenty-two inpatients with sAUD and 17 Healthy Controls (HC) completed two impulsivity scales: the Barratt Impulsiveness Scale-11 (BIS-11), and the Urgency, Premeditation, Perseverance, Sensation Seeking, Positive Urgency Impulsive Behavior Scale (UPPS). They also underwent an anatomical MRI. The brain volumes of the regions described as involved in the three subcomponents of the triadic model were extracted.

RESULTS

The two groups did not significantly differ on self-reported impulsivity measures. However, the volumes of the caudate nuclei, executive cerebellum and insula were smaller in sAUD than in HC. In the sAUD group there were significant positive correlations between certain impulsivity measures and gray matter volume of the nucleus accumbens.

CONCLUSIONS

In sAUD, self-evaluated impulsivity specifically relates to the integrity of the ventral striatum that belongs to the impulsive subcomponent of the triadic neurocognitive model of addiction. It is not related to the integrity or deterioration of the brain regions that underlie the reflexive or regulatory sub-component. Although these results have methodological limitations, they are consistent with the impulsive/compulsive model of addiction and confirms the persistence of the relationship between impulsivity and ventral striatum in sAUD.

Children engage neural reward structures for creative musical improvisation

Children spontaneously engage in creative behaviors. However, little is known about the biological underpinnings of creativity in children. We identified neural substrates associated with musical improvisation in children aged 9-11. Participants played a non-ferromagnetic piano keyboard in a functional magnetic resonance imaging (fMRI) scanner using a musical paradigm that required no prior musical experience, in which they played a rote pattern from memory or improvised melodies using those same notes. fMRI analysis of children's brains during musical improvisation revealed (1) heightened functional connectivity between emotion and reward brain areas and (2) deactivation of auditory, limbic, and parietal structures, particularly the middle temporal gyrus, angular gyrus, precuneus, and cingulate cortex. Importantly, improvisation engaged reward structures more than the control condition. Neural results suggest that children possess nascent creativity networks that form the roots for later adult creativity networks.

Abnormal brain functional networks in systemic lupus erythematosus: a graph theory, network-based statistic and machine learning study

Systemic lupus erythematosus patients' brain functional network impairments are incompletely clarified. This study investigates the brain functional network topological alterations in systemic lupus erythematosus and the application of machine learning to the classification of systemic lupus erythematosus and healthy controls. Resting-state functional MRI data from 127 systemic lupus erythematosus patients and 102 healthy controls were used. The pre-processing process involved using automated anatomical labelling atlas to compute time series data for 116 brain regions. A functional connectivity network was then created by assessing the Pearson correlation between the time series of these brain regions. The GRETNA toolbox was used to compute the difference in topological attributes between groups. Variations in regional networks among groups were evaluated using non-parametric permutation tests that rely on network-based statistical analysis. With the functional connectivity network metrics as features and network-based statistical analysis as the feature selection method, network-based statistical analysis Predict software was used to classify systemic lupus erythematosus from controls by support vector machine. The subnets that contributed the most to systemic lupus erythematosus classification were also identified. For global indicators, the systemic lupus erythematosus group exhibited significantly lower values for the normalized clustering coefficient (P = 0. 0317) and small-world index (P = 0.0364) compared to the healthy controls group. After false discovery rate correction, the differences in Betweeness Centrality, Degree Centrality, Node Efficiency, Node Local Efficiency and other local indexes between the two groups were not retained. No correlation was found between clinical data and network indicators. Systemic lupus erythematosus group had a significantly reduced connection with a 12-node, 11-edge subnetwork (P = 0.024). In conclusion, systemic lupus erythematosus patients exhibit suboptimal global brain functional connectivity network topology and the presence of a subnetwork with abnormally reduced connectivity.

Music therapy in psychological and educational context: Enhancing emotional and cognitive development of students

In recent years, music therapy has gained popularity, sparking interest in examining its effectiveness. The primary objective of this article is to analyze the effectiveness of an intervention program of music therapy on the emotional and cognitive development of young individuals. The study design is the intervention-control study. The participants consisted of 140 students from a university in Ukraine: 70 individuals diagnosed with clinical depression and 70 individuals who did not report any psychological disorders. The instruments utilized included the Psychological General Well-Being Index, Wechsler Memory Scale, and Conners' Continuous Performance Test-Second Edition. The results indicated that music therapy led to a significant improvement in the measured parameters across both contexts, albeit with varying degrees of effectiveness. In the educational context, psychological well-being increased by 10.40 points (p = 0.000), memory by 1.89 points (p = 0.005), and attention by 1.69 points (p = 0.000). In the psychological context, the effects were more pronounced: psychological well-being increased by 11.92 points, memory by 3.31 points, and attention by 1.57 points (all p = 0.000). Furthermore, effect size analysis revealed that music therapy exerted a very large impact in the psychological context on psychological well-being (d = 3.71), memory (d = 2.67), and attention (d = 1.17), whereas in the educational context, the effects were significant but comparatively lower (d = 4.36, 0.90, and 0.67, respectively). These findings highlight the differential impact of music therapy depending on the context of its implementation, emphasizing the necessity of context-specific approaches to maximize its benefits. This study contributes to the growing body of research demonstrating the effectiveness of music therapy in both psychological treatment and educational enhancement, supporting its broader integration into mental health and academic settings.

Neural network localization in Parkinson's disease with impulse control disorders

Background

There is a huge heterogeneity of magnetic resonance imaging findings in Parkinson's disease (PD) with impulse control disorders (ICDs) studies. Here, we hypothesized that brain regions identified by structural and functional imaging studies of PD with ICDs could be reconciled in a common network.

Methods

In this study, an initial systematic literature review was conducted to collect and evaluate whole-brain functional and structural magnetic resonance imaging studies related to PD with ICDs. We subsequently utilized the Human Connectome Project (HCP) dataset (n = 1,093) and a novel functional connectivity network mapping (FCNM) technique to identify a common brain network affected in PD with ICDs.

Results

A total of 19 studies with 25 contrasts, incorporating 345 individuals with PD and ICDs, and 787 individuals with PD without ICDs were included in the analysis. By using the HCP dataset and a novel FCNM technique, we ultimately identified that the aberrant neural networks predominantly involve the default mode network (middle and inferior temporal gyrus, anterior cingulate cortex, angular gyrus) and subcortical network (caudate nucleus).

Conclusion

This study suggests that the heterogeneous neuroimaging findings in PD with ICDs can be attributed to shared abnormalities in the default mode and subcortical networks. These dysfunctions are associated with impaired self-regulation, decision-making, and heightened impulsivity in PD with ICDs. Our findings integrate diverse neuroimaging results from previous studies, providing a clearer understanding of the neurobiological mechanisms underlying PD with ICDs at a network level.

Brain Structural Alterations Underlying Mood-Related Deficits in Schizophrenia

Background/Objectives: Schizophrenia (SZ) is a complex psychiatric disorder characterized by neurodegenerative processes, but the structural brain alterations associated with its progression remain poorly understood. This study investigated structural brain changes in SZ, particularly in the fronto-temporal and limbic regions, and explored their relationship with symptom severity, with a focus on mood- and emotion-related symptoms. Methods: We analyzed structural MRI data from 74 SZ patients and 91 healthy controls (HCs) using voxel-based morphometry (VBM) to compare whole-brain grey matter volumes (GMVs). The analysis focused on the fronto-temporal and limbic regions, and correlations between GMV and symptom severity were assessed using the Positive and Negative Syndrome Scale (PANSS) and the Generalized Psychopathology (GP) scale. Results: SZ patients exhibited significant reductions in GMV in the fronto-temporal and limbic regions, including the dorsolateral prefrontal cortex (dlPFC) and the temporal pole, compared to HCs. Notably, a significant positive association was found between GMV in the right inferior temporal gyrus (ITG) and the severity of generalized psychopathology, as well as with anxiety, depression, mannerisms, and unusual thought content. Further post hoc analysis identified a specific cluster of mood-related symptoms contributing to the GP scale, which correlated with GMV changes in the right ITG. Conclusions: Our findings provide new evidence of structural brain alterations in SZ, particularly in the fronto-temporal and limbic regions, suggesting a progressive neurodegenerative pattern. The role of the right ITG in mood- and emotion-related symptoms requires further exploration, as it could offer insights into SZ pathophysiology and aid in distinguishing SZ from other mood-related disorders.

Dual temporal pathway model of emotion processing based on dynamic network reconfiguration analysis of EEG signals

Emotion is crucial for the quality of daily life. Recent findings suggest that the cooperation and integration of multiple brain regions are essential for effective emotion processing. Additionally, network reconfiguration has been observed during various cognitive tasks. However, it remains unclear how the brain responds to different emotional categories under natural stimuli from the perspective of network reconfiguration, or whether this reconfiguration can predict subjective rating scores. To address this question, 28 video clips were used to evoke eight distinct emotion categories, and the participants' electroencephalogram (EEG) signals were recorded. Dynamic network reconfiguration analysis was performed on brain networks extracted from band-limited EEG signals using the phase locking value (PLV) across multiple non-overlapping time windows. Robust dynamic community detection was applied to these networks, followed by quantification of integration and segregation at both node- and community-level changes. Multidimensional rating scores were collected for each clip. The analysis revealed that the metrics of dynamic network reconfiguration could predict subjective ratings. Specifically, longer EEG segments improved predictions for positive emotions, whereas shorter segments were more effective for negative emotions. Our study provides empirical evidence integrating the dual-process model and the theory of constructed emotion. Based on observed spatiotemporal patterns of global integration and segregation across the brain, we propose the dual temporal pathway model for emotional processing across various emotion categories, highlighting fast and slow neural processes associated with negative and positive emotions, respectively. These findings offer valuable support for developing temporally targeted diagnostic and therapeutic strategies for emotion-related brain disorders.

Prosocial Helping Behavior: Conceptual Issues and Neural Mechanisms

Prosocial helping behavior, characterized by voluntary actions taken to benefit others, plays a vital role in promoting cooperation and maintaining social bonds across human and animal social groups. In this review, we examine key conceptual issues surrounding prosocial behavior, focusing specifically on targeted helping and comforting actions. We outline the behavioral paradigms used to study these two types of prosocial behaviors and summarize recent insights into their underlying neural mechanisms. Drawing on findings across species and with an emphasis on rodent models, we discuss how these behaviors are regulated by molecularly and anatomically defined neural systems and how distinct neuronal populations and circuits may differentially regulate targeted helping and comforting behaviors. Lastly, we discuss the clinical relevance of this research by addressing the implications of prosocial deficits in psychiatric disorders.

Faces in shadows: silhouette light, underlight and toplight elicit increased early posterior negativity

One key aspect of film lighting, and light in general, is its direction and how it illuminates people and other objects of attention. This research article presents the results of a pilot EEG experiment that studied the emotional responses of nine test subjects to photographs of an expressionless human face lit from varying directions. The aim of the study was to examine, how the direction of the main light source illuminating the face-the so-called 'key light' in filmmaking-would affect the test subjects' subliminal-level emotional response before any conscious emotional processing takes place. EEG studies on how facial lighting affects the viewers' subliminal emotions have not been reported in academic literature but, on the other hand, facial expressions and other emotion-eliciting visuals have been studied extensively. Based on a number of previous studies on subliminal emotions, the Early Posterior Negativity (EPN) measured in the occipito-parietal area of the scalp was chosen as the event-related potential (ERP) of interest, as it has been reported to reflect the subliminal processing of faces, facial expressions, and other visuals of evolutionary interest such as dangerous animals. Three light directions, (1) silhouette light that completely hides facial features, (2) underlight that comes from below the face and distorts those features, and (3) toplight that hides the eyes, were found to elicit a statistically more negative EPN than 45-degree light, a lighting style that reveals the whole face, gives the subject depth and separation from the background, and is therefore often used as the chosen key light direction in filmmaking and portrait photography, for example in the so-called three-point lighting technique. Contributing to cognitive film studies, these results indicate that the way a character's face is lit affects the film experience as a whole already at the subliminal level of emotional processing.

Pleiotropic Effects of Grm7/GRM7 in Shaping Neurodevelopmental Pathways and the Neural Substrate of Complex Behaviors and Disorders

Natural gene variants of metabotropic glutamate receptor subtype 7 (Grm7), coding for mGluR7, affect individuals' alcohol-drinking preference. Psychopharmacological investigations have suggested that mGluR7 is also involved in responses to cocaine, morphine, and nicotine exposures. We review the pleiotropic effects of Grm7 and the principle of recombinant quantitative trait locus introgression (RQI), which led to the discovery of the first mammalian quantitative gene accounting for alcohol-drinking preference. Grm7/GRM7 can play important roles in mammalian ontogenesis, brain development, and predisposition to addiction. It is also involved in other behavioral phenotypes, including emotion, stress, motivated cognition, defensive behavior, and pain-related symptoms. This review identified pleiotropy and the modulation of neurobehavioral processes by variations in the gene Grm7/GRM7. Patterns of pleiotropic genes can form oligogenic architectures whosecombined additive and interaction effects can significantly predispose individuals to the expressions of disorders. Identifying and characterizing pleiotropic genes are necessary for understanding the expressions of complex traits. This requires tasks, such as discovering and identifying novel genetic elements of the genetic architecture, which are unsuitable for AI but require classical experimental genetics.

The brain-heart axis: integrative cooperation of neural, mechanical and biochemical pathways

The neural and cardiovascular systems are pivotal in regulating human physiological, cognitive and emotional states, constantly interacting through anatomical and functional connections referred to as the brain-heart axis. When this axis is dysfunctional, neurological conditions can lead to cardiovascular disorders and, conversely, cardiovascular dysfunction can substantially affect brain health. However, the mechanisms and fundamental physiological components of the brain-heart axis remain largely unknown. In this Review, we elucidate these components and identify three primary pathways: neural, mechanical and biochemical. The neural pathway involves the interaction between the autonomic nervous system and the central autonomic network in the brain. The mechanical pathway involves mechanoreceptors, particularly those expressing mechanosensitive Piezo protein channels, which relay crucial information about blood pressure through peripheral and cerebrovascular connections. The biochemical pathway comprises many endogenous compounds that are important mediators of neural and cardiovascular function. This multisystem perspective calls for the development of integrative approaches, leading to new clinical specialties in neurocardiology.

Anatomic distribution of kisspeptin neurons in the adult sheep amygdala: Associations with sex, estrogen receptor alpha, androgen receptor, and sexual partner preference

Kisspeptin neurons are primarily known for regulating reproductive function by stimulating hormone release that controls puberty and fertility. While typically associated with the hypothalamus, recent research suggests their presence in other brain regions, including the amygdala. The amygdala, crucial for emotional processing and social behaviors, consists of various nuclei. However, the specific distribution and potential functional implications of kisspeptin neurons within this region remain unclear. Understanding kisspeptin neuron distribution in the sheep amygdala could provide insights into their roles in modulating reproductive functions, emotional, and social behaviors in a species closely related to humans. This study employed immunohistochemistry and RNAscope™ fluorescent in situ hybridization to map the distribution of kisspeptin fibers and cells in the amygdala of intact adult male and luteal-phase female sheep. The research also investigated the co-expression of Kiss1 with estrogen receptor-α (ESR1) and androgen receptor (AR) mRNA, as well as the presence of kisspeptin receptor (Kiss1r) mRNA-containing cells. Kisspeptin immunoreactive fibers were most dense in the medial amygdala, while Kiss1 mRNA-containing cells were abundant in the medial, cortical, and basal nuclei. Extensive co-expression of Kiss1 with ESR1 and AR mRNA was observed. In the posterior medial nucleus, 80% of kisspeptin neurons co-expressed ESR1, and 40% co-expressed AR. Kiss1r mRNA-containing cells were found in the medial, cortical, and basal nuclei and co-localized within cells expressing Kiss1 mRNA. No differences in kisspeptin cell numbers were found between rams and ewes or between rams with different sexual partner preferences. This study provides a foundational map of the kisspeptin system in the sheep amygdala, offering insights into its potential roles in reproductive, emotional, and social behaviors. The extensive co-expression of Kiss1 mRNA with ESR1 and AR mRNA suggests possible regulation by sex steroids, while the presence of Kiss1r mRNA-containing cells indicates potential autocrine or paracrine signaling. These findings contribute to our understanding of kisspeptin neurons' distribution and potential functions beyond the hypothalamus, particularly in the amygdala.

Preliminary pharmacokinetics and in vivo studies indicate analgesic and stress mitigation effects of a novel NMDA receptor modulator

N-methyl D-aspartate receptor (NMDAR) channel blockers produce analgesic and antidepressant effects by preferentially inhibiting the GluN2D subtype at lower doses. Given the distinct physiological role of GluN2 subunits, we hypothesized that compounds capable of simultaneously modulating GluN2A and GluN2D subtypes in opposite directions could serve as effective analgesics with minimal cognitive adverse effects. In this translational study, we investigated the in vivo effects of costa NMDAR stimulator 4 (CNS4), a recently discovered glutamate concentration-dependent NMDAR modulator. Pharmacokinetic data revealed that CNS4 reaches peak plasma and brain concentrations within 0.25 hours after intraperitoneal injection, with brain concentrations reaching values up to 8.4% of those in plasma (64.9 vs 5.47 μg/mL). Preliminary results showed that CNS4, a nonopioid compound, increased escape latency in mice during a hotplate assay by 1.74-fold compared with saline. In a fear conditioning experiment, CNS4 anecdotally reduced the electric shock sensation and significantly decreased stress-related defecation (fecal pellets: males, 21 vs 1; females, 19 vs 3). CNS4 also improved hyperarousal behavior (25 vs 4 jumps), without affecting fear memory parameters such as freezing episodes, duration, or latency. CNS4 caused no changes in locomotion across 8 of 9 parameters studied. Remarkably, approximately 50 hours after fear conditioning training, CNS4 prevented stress-induced excessive sucrose drinking behavior by more than 2-fold both in male and female mice. These findings suggest that CNS4 penetrates brain tissue and produces pharmacological effects such as those of NMDAR-targeting drugs but with a distinct mechanism, avoiding the undesirable side effects typical of traditional NMDAR blockers. Therefore, CNS4 holds potential as a novel nonopioid analgesic, warranting further investigation. SIGNIFICANCE STATEMENT: N-methyl D-aspartate (NMDA)-subtype glutamate receptors are an attractive target for chronic pain and posttraumatic stress disorder treatments because they play a critical role in forming emotional memories of stressful events. In this translational pharmacology work, we demonstrate the central analgesic and stress-mitigating characteristics of a novel glutamate concentration-biased NMDA receptor modulator, costa NMDA receptor stimulator 4.

Triangular Causality Among Pulmonary Hypertension, Sleep Disorders, and Brain Structure at the Genetic Level: A Mendelian Randomization Study Focused on the Lung-Brain Axis

Background

The bidirectional relationship between pulmonary hypertension (PH) and sleep disorders has attracted significant research attention. The concept of the lung-brain axis has further highlighted the need for a holistic approach to managing these diseases.

Methods

This study used bidirectional two-sample Mendelian Randomization (MR) to explore the genetic-level causal relationships between PH, sleep disorders, and structural brain changes. GWAS data for PH were pooled from four cohorts; data on four sleep disorder subtypes were sourced from the FinnGen database; and data on 15 structural brain changes were obtained from the ENIGMA Consortium. To ensure reliability, we applied strict data selection, multiple corrections, heterogeneity assessments, and sensitivity tests. Visualizations included forest plots, scatter plots, funnel plots, and leave-one-out plots.

Results

MR analysis revealed a significant causal relationship between PH and both obstructive sleep apnea (OSA) (OR = 1.022, 95% CI = 1.006-1.039, P = 0.006, PBonferroni = 0.025) and general sleep disorders (OR = 1.018, 95% CI = 1.003-1.033, P = 0.018, PFDR = 0.036), with no evidence of reverse causation and multivariable MR analyses also demonstrated significant results. PH was linked to changes in total brain volume (P = 0.032) and cerebral white matter (P = 0.035). Amygdala changes appeared to reduce the risk of sleep disorders (P = 0.008) and OSA (P = 0.014). Sensitivity analyses showed no heterogeneity, pleiotropy, or significant outliers.

Conclusion

This study identifies significant causal links between PH, sleep disorders, and structural brain changes, establishing a triangular cyclic relationship that supports the lung-brain axis concept. These findings inform clinical management of PH and its comorbidities.

From Neural Networks to Emotional Networks: A Systematic Review of EEG-Based Emotion Recognition in Cognitive Neuroscience and Real-World Applications

BACKGROUND/OBJECTIVES

This systematic review presents how neural and emotional networks are integrated into EEG-based emotion recognition, bridging the gap between cognitive neuroscience and practical applications.

METHODS

Following PRISMA, 64 studies were reviewed that outlined the latest feature extraction and classification developments using deep learning models such as CNNs and RNNs.

RESULTS

Indeed, the findings showed that the multimodal approaches were practical, especially the combinations involving EEG with physiological signals, thus improving the accuracy of classification, even surpassing 90% in some studies. Key signal processing techniques used during this process include spectral features, connectivity analysis, and frontal asymmetry detection, which helped enhance the performance of recognition. Despite these advances, challenges remain more significant in real-time EEG processing, where a trade-off between accuracy and computational efficiency limits practical implementation. High computational cost is prohibitive to the use of deep learning models in real-world applications, therefore indicating a need for the development and application of optimization techniques. Aside from this, the significant obstacles are inconsistency in labeling emotions, variation in experimental protocols, and the use of non-standardized datasets regarding the generalizability of EEG-based emotion recognition systems.

DISCUSSION

These challenges include developing adaptive, real-time processing algorithms, integrating EEG with other inputs like facial expressions and physiological sensors, and a need for standardized protocols for emotion elicitation and classification. Further, related ethical issues with respect to privacy, data security, and machine learning model biases need to be much more proclaimed to responsibly apply research on emotions to areas such as healthcare, human-computer interaction, and marketing.

CONCLUSIONS

This review provides critical insight into and suggestions for further development in the field of EEG-based emotion recognition toward more robust, scalable, and ethical applications by consolidating current methodologies and identifying their key limitations.

Early life stress and brain development: Neurobiological and behavioral effects of chronic stress

Early life stress is the term used to describe a variety of traumatic events that a person may have as a kid, such as being subjected to domestic or public violence, being neglected, experiencing parental conflict, being abused physically, emotionally and sexually. These events have the potential to seriously impair the brains normal growth and development, which could have long term psychological and physiological repercussions. Early life stress (ELS) has profound and enduring effects on brain development, contributing to long-term neurological and behavioral changes. Neurologically, ELS can reduce hippocampal volume, impairing memory and emotional regulation, while also sensitizing the amygdala, leading to exaggerated fear and anxiety responses. Additionally, ELS can disrupt the development of the prefrontal cortex (PFC), affecting decision-making, planning, and impulse control. It also alters neurotransmitter systems, such as serotonin and dopamine, influencing mood and motivation, and can trigger chronic neuroinflammation, increasing the risk of neurodegenerative diseases. Behaviorally, ELS heightens the risk of anxiety, depression, and impulsivity, and can contribute to conditions like ADHD and substance abuse Social and emotional difficulties, such as challenges in relationships and empathy, often arise, along with cognitive impairments in learning and memory. Furthermore, ELS increases stress responsiveness, making individuals more vulnerable to future stress. However, these effects can be mitigated by supportive environments and targeted interventions.

Diagnosis of major depressive disorder using a novel interpretable GCN model based on resting state fMRI

The diagnosis and analysis of major depressive disorder (MDD) faces some intractable challenges such as dataset limitations and clinical variability. Resting-state functional magnetic resonance imaging (Rs-fMRI) can reflect the fluctuation data of brain activity in a resting state, which can find the interrelationships, functional connections, and network characteristics among brain regions of the patients. In this paper, a brain functional connectivity matrix is constructed using Pearson correlation based on the characteristics of multi-site Rs-fMRI data and brain atlas, and an adaptive propagation operator graph convolutional network (APO-GCN) model is designed. The APO-GCN model can automatically adjust the propagation operator in each hidden layer according to the data features to control the expressive power of the model. By adaptively learning effective information in the graph, this model significantly improves its ability to capture complex graph structural patterns. The experimental results on Rs-fMRI data from 1601 participants (830 MDD and 771 HC) and 16 sites of REST-meta-MDD project show that the APO-GCN achieved a classification accuracy of 91.8%, outperforming those of the state-of-the-art classifier methods. The classification process is driven by multiple significant brain regions, and our method further reveals functional connectivity abnormalities between these brain regions, which are important biomarkers of classification. It is worth noting that the brain regions identified by the classifier and the networks involved are consistent with existing research results, which suggest that the pathogenesis of depression may be related to dysfunction of multiple brain networks.

The Implementation of Infant Anoesis and Adult Autonoesis in the Retrogenesis and Staging System of the Neurocognitive Disorders: A Proposal for a Multidimensional Person-Centered Model

Background: Retrogenesis is the process by which the degenerative and vascular mechanisms of dementia reverse the order of acquisition in the normal development. Objective: The development of memory/knowledge after birth may help to know the biopsychosocial and functional characteristics (biosphere) of the retrogenesis. Methods: A literature review was performed in the PubMed, Google Scholar, and Scopus databases using 43 keywords related to retrogenesis: 234 eligible records were selected. Results: The infantile amnesia, characterized from anoesis, was described along the infant/child's biosphere in which the limbic system progressively develops the acquisition of the body knowledge (Anoetic Body Consciousness, AnBC). Anoesis is the infant memory state characterized by the absence of long-term memories of the many stressful/painful experiences that accompany the acquisition under the long-life voluntary control of the long-term memories fundamental for the body growth and survival (mainly chewing/swallowing and walking). At the age of 3-4 years, usually, the AnBC evolves, as a continuum, into the adulthood autonoesis with the emergence, in the child/adolescent, of the consciousness of "self" trough the development of the Episodic Autobiographic Memory (EAM) and the Autonoetic Mind Consciousness (AuMC). The development of cognition and knowledge is due to the progressive maturation of the whole limbic system and not only of the hippocampus. In the biopsychosocial retrogenesis, the EAM/AuMC vanishes progressively along the mild, moderate, and severe stages of dementia when the infant AnBC resurfaces, losing progressively the basic activities of daily living in a retrogenetic order of acquisition where the last functions to disappear are chewing/swallowing. Conclusion: The transition from the adult EAM-AuMC to the infant AnBC, as a continuum in the individual biosphere, adds a contribution to the assessment of the retrogenesis in dementia from a multidimensional person-centered model.

Amygdala Nuclei Atrophy in Cognitive Impairment and Dementia: Insights from High-Resolution Magnetic Resonance Imaging

Background and Objectives: Cognitive impairment affects memory, reasoning, and problem-solving, with early detection being critical for effective management. The amygdala, a key structure in emotional processing and memory, may play a pivotal role in detecting cognitive decline. This study examines differences in amygdala nuclei volumes in patients with varying levels of cognitive performance to evaluate its potential as a biomarker. Material and methods: This cross-sectional study of 35 participants was conducted and classified into three groups: the normal (≥26), moderate (15-25), and low (≤14) cognitive performance groups based on the Montreal Cognitive Assessment (MoCA) scores. High-resolution magnetic resonance imaging at 3.0 T scanner was used to assess amygdala nuclei volumes. Results: Significant amygdala atrophy was observed in multiple amygdala nuclei across cognitive performance groups, with more pronounced changes in the low-performance group. The right hemisphere nuclei, including the lateral and basal nuclei, showed more significant differences, indicating their sensitivity to cognitive decline. Conclusions: This study highlights the potential of amygdala nuclei atrophy as a biomarker for cognitive impairment. Additional research with larger sample sizes and longitudinal designs is needed to confirm these findings and determine their diagnostic value.

Early life stress and functional connectivity in antipsychotic-naïve first episode psychosis patients

The neural mechanisms underlying the association between childhood trauma (CT) and psychosis spectrum disorders remains unclear. The objective of this study is to examine the relationship between childhood trauma and functional connectivity of fronto-limbic regions in a large sample of antipsychotic-naïve patients with first episode psychosis (FEP). Resting state fMRI data from 105 FEP patients and 123 healthy controls (HC) were used. Our regions of interest included bilateral hippocampus/amygdala and ventromedial prefrontal cortex (vmPFC). Childhood Trauma Questionnaire (CTQ) total and subscale scores were correlated with the resting state functional connectivity (rsFC) data. Partial correlation analyses indicated that higher CTQ sexual abuse subscale scores in FEP patients were associated with increased left amygdala-vmPFC rsFC (r(59) = 0.27, p < 0.05) and higher CTQ emotional neglect subscale scores in FEP patients were associated with increased left hippocampus-vmPFC rsFC (r(59) = 0.26, p < 0.05). Follow-up analysis showed a significant interaction effect of group (FEP and HC) and CTQ score (sexual abuse subscale) on left amygdala-vmPFC rsFC (β = 0.014, p < 0.05). Higher CTQ sexual abuse subscale scores were associated with increased rsFC in FEP patients (β = 0.56, p < 0.001). but reduced rsFC in healthy controls (β = -0.56, p < 0.001). The results also provide support for the long-term differential impact of trauma subtypes on the human brain. Overall, the results contribute to the understanding of the neural mechanisms underlying the association between childhood trauma and psychosis spectrum disorders.

Examining Specific Theory-of-Mind Aspects in Amnestic and Non-Amnestic Mild Cognitive Impairment: Their Relationships with Sleep Duration and Cognitive Planning

Background/Objectives: The study examined the relationships between specific Theory-of-Mind (ToM) dimensions, cognitive planning, and sleep duration in aging adults. Methods: The sample included 179 participants, comprising 46 cognitively healthy individuals, 75 diagnosed with amnestic Mild Cognitive Impairment (aMCI), and 58 with non-amnestic (naMCI). The mean age of the participants was 70.23 years (SD = 4.74), with a mean educational attainment of 12.35 years (SD = 3.22) and gender distribution of 53 men and 126 women. ToM assessment included tasks measuring the understanding and interpretation of non-literal speech, proverbs and metaphors, as well as an emotion-recognition test. For cognitive planning, a Tower Test was utilized. Sleep duration was measured using actigraphy. Results: We identified significant differences in various ToM tasks' performance between the groups, particularly in non-literal speech tasks and third-order ToM stories. The HC group consistently outperformed both MCI groups in these tasks, with aMCI showing higher performance than naMCI. Mediation analysis applied to examine potential direct and indirect effects of sleep duration on ToM tasks indicated that total sleep time had significant indirect effects through cognitive planning-mainly as rule violation total score-on specific ToM aspects. Hence, besides the effects of MCI pathologies and especially of naMCI, sleep duration seems also to be associated with ToM performance in aging via specific executive functioning decrements. Conclusions: The findings underscore the social implications of ToM deficits due to MCI and/or sleep duration decrease, particularly in naMCI older adults, as they can seriously impair their social interactions. Targeted interventions could improve emotional understanding, communication, and overall quality of life.

Navigating the fear: assessing nursing students' concerns and preventive practices in response to Monkeypox in Egypt

BACKGROUND

Monkeypox has emerged as a global health concern, necessitating preventive measures and awareness among healthcare students. Understanding nursing students' fears, concerns, and preventive practices regarding Monkeypox can help improve preparedness and response strategies.

AIM

This study aimed to assess the levels of fear, concerns, and preventive practices related to monkeypox among nursing students at Beni Suef University, Egypt, during the 2024-2025 academic year.

METHODS

A cross-sectional descriptive design was employed, involving 505 nursing students systematically randomized recruited. Data collection utilized three validated tools: the Monkeypox Fear Scale, Monkeypox Concern Scale, and Monkeypox Preventive Practices Scale. Reliability was confirmed with Cronbach's alpha values ranging from 0.87 to 0.94. Data analysis included descriptive statistics, Spearman correlation, and multiple linear regression using SPSS Version 23.

RESULTS

Most (56.2%) students rarely worried about Monkeypox infection, though 49.2% reported anxiety influenced by media coverage. High preventive practices were noted, with 60.6% frequently practicing hygiene measures. A strong positive correlation between Monkeypox concern and fear (r = 0.646, p < 0.001) and a moderate positive correlation between Monkeypox concern and preventive practices (r = 0.229, p = 0.001). Fear was also significantly correlated with preventive practices (r = 0.432, p < 0.001). Multiple linear regression analysis (R² = 0.216, F = 22.633, p < 0.001) revealed that fear was a strong positive predictor of preventive practices, while Monkeypox concern had a positive but non-significant effect (B = 0.138, p = 0.156). Age was not a significant predictor (B = 0.251, p = 0.637), whereas family income showed a significant negative association (B = -1.885, p = 0.010).

CONCLUSION

The study revealed moderate fear and concerns among nursing students, with generally high adherence to preventive practices.

IMPLICATION

Findings suggest the need for targeted health education programs to address monkeypox-related concerns and enhance preventive measures, thus improving nursing students' readiness to respond to emerging health threats.

Emotional salience network involved in constructing two-dimensional fear space in humans

Fear learning is pivotal for organismal survival, ensuring the ability to avoid potential threats through learning based on experiencing minimal fear information. In reality, fear learning requires to form a structured representation of fear experiences from multiple dimensions in order to support flexible use in ever-changing environment. Yet, the underlying neural mechanisms of constructing dimensional fear space remain elusive. Here we set up an innovative approach with two-dimensional fear learning, by utilizing the probability (uncertainty) and subjective pain intensity of threatening mild electric shock with five levels of each dimension. Behaviorally, individuals constructed a two-dimensional fear space after learning phase, as evidenced by significant changes in participant's fearful ratings for each cue associated with a five-by-five grid after (relative to before) learning phase. Analysis of neuroimaging data revealed that the medial temporal lobe, in conjunction with the amygdala, the insula, the anterior cingulate cortex (ACC), the hippocampus, and the dorsolateral prefrontal cortex (dlPFC), collectively contribute to the construction of a two-dimensional fear space consisting of uncertainty and intensity. Activation in the parahippocampal gyrus, insula, and dlPFC was associated with mental navigation within two-dimensional fear space, whereas the engagement of insula, ACC, amygdala, the hippocampus, the dlPFC was associated with a unified fearful scoring cross uncertainty and intensity dimensions after fear learning. Our findings suggest a neurocognitive model through which emotional salience network underlies the construction of a structured representation of fear experiences from multiple dimensions.

Neuromodulation as a therapeutic approach for post-traumatic stress disorder: the evidence to date

INTRODUCTION

Post-traumatic stress disorder (PTSD) can have debilitating effects on quality of life, and conventional treatments show mixed results. Neuromodulation is emerging as a promising approach for treating PTSD. This review examines current neuromodulatory treatments for PTSD, and highlights methodologies, clinical outcomes, and gaps in the literature to help guide future research.

AREAS COVERED

A PubMed search identified 252 studies on PTSD and neuromodulation, of which 61 were selected for full review. These included 37 studies on repetitive transcranial magnetic stimulation (rTMS), 10 on transcranial direct current stimulation (tDCS),4 on deep brain stimulation (DBS) and 2 on focused ultrasound (FUS).

EXPERT OPINION

The present review supports the potential of neuromodulation to reduce PTSD symptoms. rTMS and tDCS targeting the dlPFC appear effective through modulating neural circuits involved in fear processing and conditioning, however, literature varies regarding efficacy of stimulation frequencies and hemispheric targets. DBS targeting the amygdala or subcallosal cingulate white matter tracts improves treatment of refractory PTSD with sustained benefits, while FUS may improve symptoms through targeted modulation of brain structures such as the amygdala, though this technique is in the early stages of exploration. Future research should refine established neuromodulatory approaches and address gaps in emerging modalities to enhance treatment efficacy.

Heterogeneity in Category Recognition across the Visual Field

Visual information emerging from the extrafoveal locations is important for visual search, saccadic eye movement control, and spatial attention allocation. Our everyday sensory experience with visual object categories varies across different parts of the visual field which may result in location-contingent variations in visual object recognition. We used a body, animal body, and chair two-forced choice object category recognition task to investigate this possibility. Animal body and chair images with various levels of visual ambiguity were presented at the fovea and different extrafoveal locations across the vertical and horizontal meridians. We found heterogeneous body and chair category recognition across the visual field. Specifically, while the recognition performance of the body and chair presented at the fovea were similar, it varied across different extrafoveal locations. The largest difference was observed when the body and chair images were presented at the lower-left and upper-right visual fields, respectively. The lower/upper visual field bias of the body/chair recognition was particularly observed in low/high stimulus visual signals. Finally, when subjects' performances were adjusted for a potential location-contingent decision bias in category recognition by subtracting the category detection in full noise condition, location-dependent category recognition was observed only for the body category. These results suggest heterogeneous body recognition bias across the visual field potentially due to more frequent exposure of the lower visual field to body stimuli.

The Role of Basolateral Amygdala and Medial Prefrontal Cortex in Fear: A Systematic Review

Fear is a primary adaptive response to potential threats. It triggers a complex cascade of physiological, cognitive, and behavioral changes that prepare an organism to cope with dangerous situations. The basolateral amygdala (BLA) and medial prefrontal cortex (mPFC) are both linked to adaptation, the generation of strong emotions, and decision-making. In this systematic review, we aimed to analyze recent studies of the connections between the BLA and mPFC in the context of their neuroanatomy, cellular composition, micro-circuitry, and involvement in fear. Utilizing the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) 2020 guidelines, our search strategy involved scouring articles from PubMed (National Center for Biotechnology Information, Bethesda, Maryland), Google Scholar (Google, Mountain View, CA), and Science Direct (Elsevier, Amsterdam, Netherlands) databases covering the last decade (2014-2024). Thirty-two rigorously evaluated studies formed the essence of our review. Review findings revealed complex bidirectional connectivity between BLA and mPFC, with distinct roles for different subregions. The rostral BLA primarily projects to the prelimbic cortex, while the caudal BLA connects with the infralimbic cortex. These circuits show specialized cellular composition, with BLA containing principal excitatory neurons and GABAergic interneurons, while mPFC exhibits layer-specific synaptic connections. Fear processing involves dynamic interactions between these regions, with the prelimbic cortex promoting fear expression and the infralimbic cortex facilitating extinction. The analysis showed that astrocytic signaling and N-methyl-D-aspartate (NMDA) receptor activation are essential in the process of both fear memory formation and its extinction. There was evidence that dysregulation of specific circuits is associated with the pathophysiology of several other psychiatric disorders, such as post-traumatic stress disorder (PTSD), anxiety disorders, and schizophrenia. This review clarifies that the BLA-mPFC circuitry is critical in perceiving fear and its regulation. The results highlight the importance of the interactions between brain regions and the types of cells in each region to respond appropriately to fear and its extinction. Uncovering such type of dysregulation further helps to understand the mechanisms of fear-associated disorders and may suggest further treatment options. Future research should focus on cellular plasticity mechanisms, translational applications, and the influence of individual factors on fear processing to develop more effective treatments for psychiatric conditions involving fear dysregulation.

The impact of aging on HIV-1-related neurocognitive impairment

Depending on the population studied, HIV-1-related neurocognitive impairment is estimated to impact up to half the population of people living with HIV (PLWH) despite the availability of combination antiretroviral therapy (cART). Various factors contribute to this neurocognitive impairment, which complicates our understanding of the molecular mechanisms involved. Biological aging has been implicated as one factor possibly impacting the development and progression of HIV-1-related neurocognitive impairment. This is increasingly important as the life expectancy of PLWH with virologic suppression on cART is currently projected to be similar to that of individuals not living with HIV. Based on our increasing understanding of the biological aging process on a cellular level, we aim to dissect possible interactions of aging- and HIV-1 infection-induced effects and their role in neurocognitive decline. Thus, we begin by providing a brief overview of the clinical aspects of HIV-1-related neurocognitive impairment and review the accumulating evidence implicating aging in its development (Part I). We then discuss potential interactions between aging-associated pathways and HIV-1-induced effects at the molecular level (Part II).

Examining the relationship between subjective exercise tolerance and psychophysiological reactivity during physical stress

It has been hypothesized that one's ability to control impulses aids in sustaining effort despite experiencing painful physical sensations. Physical exercise has been used extensively as an intervention to strengthen the inhibitory control system and protect an individual's cognitive plan of action. It is unclear, however, whether the high levels of exercise tolerance could facilitate inhibitory control under varied stressors. The present study explored the relationship between subjective exercise tolerance and psychophysiological characteristics that indicate reactivity capacity when exposed to the cold pressor test. Thirty-six participants were divided into two groups based on their subjective exercise tolerance profiles. During the test, participants' psychophysiological reactivity was monitored via heart rate variability. Participants were also required to answer questions about their perceptual and affective states at the beginning and immediately after the stress test. The study revealed insights into dominance perception and emotional states among individuals with varying subjective exercise tolerance levels. High-tolerant individuals endured physical discomfort longer (~50 s) and exhibited higher perceived dominance at the outset of the test when compared to their low-tolerant counterparts. Despite differences in task performance, both groups experienced more positive affective states post-task, potentially as a result of a heightened sense of self-accomplishment. Notably, both groups showed similar levels of psychophysiological reactivity, suggesting a protective effect of physical tolerance on ensuing biological responses. Overall, this study sheds light on the complex relationship between exercise tolerance, dominance perception, and psychophysiological reactivity during physically demanding tasks, enriching our understanding of how developing physical tolerance may impact inhibitory control under stress.

Experimental Periodontitis Increases Anxious Behavior and Worsens Cognitive Aspects and Systemic Oxidative Stress in Wistar Rats

OBJECTIVES

Periodontitis (PD) has the potential to induce systemic changes that affect both physical and behavioral aspects. These alterations may be associated with changes in both the inflammatory profile and the oxidative stress status of individuals with PD. Therefore, we aimed to evaluate the effects of PD on oxidative stress, as well as on behavioral parameters and cognitive impairment, in a preclinical model.

MATERIAL AND METHODS

Twenty-four male Wistar rats were randomly assigned to PD and sham groups. PD was induced by the ligature protocol for 14 days. Behavioral tests were initiated on the 9th day of the experiment to evaluate anxious behavior and cognition (learning and memory). After euthanasia, oxidative stress was evaluated in the gums, blood, hippocampus, and amygdala. Alveolar bone loss, bone microstructure, and elemental compositions of the mandibular bone were also assessed.

RESULTS

PD increased alveolar bone loss, reduced the calcium and phosphorus content in the mandibular bone, and increased anxiety-like behavior and cognitive decline (p < 0.05). Furthermore, PD significantly affected the redox balance, as evidenced by increased total antioxidant capacity (TAC) in the gingiva and hippocampus (p < 0.05). It also led to increased lipid peroxidation in the gingiva and erythrocytes (p < 0.05), decreased antioxidant defenses in erythrocytes (superoxide dismutase) and the hippocampus (catalase), and increased antioxidant activity (catalase) in the amygdala (p < 0.05).

CONCLUSION

PD resulted in cognitive alterations, including impairments in spatial learning and memory, as well as increased anxious behavior, likely due to redox imbalance in rats.

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.

Altered structural covariance of the cortex and hippocampal formation in patients with lung cancer after chemotherapy

Objective

In this retrospective study, we aimed to investigate changes in brain morphology and structural topological networks in patients with lung cancer (LC) with or without chemotherapy.

Methods

We retrospectively recruited 191 participants for this cross-sectional study, including 113 patients with LC without chemotherapy (Ch-), 38 patients with LC with chemotherapy (Ch+), and 40 healthy controls (HC) matched for age, sex, and education. The gray matter volume (GMV) and cortical properties were compared among the three groups. We constructed the structural covariant network (SCN) based on cortical thickness, volumes of subcortical structures, and volumes of hippocampal subfields and the amygdala in all participants. The global and nodal topological properties of SCN were compared among groups. In addition, 23 patients with LC (8 Ch+ and 15 Ch-) who received two identical brain magnetic resonance scans were enrolled in the follow-up study. The paired t-test was used to compare group differences in brain morphology and topological properties in the structural network.

Results

The GMV of the bilateral caudate and thalamus were smaller in the Ch- and Ch + groups compared to the HC group using threshold-free cluster enhancement and permutation (P < 0.05, 5000 times permutations) for multiple comparison correction. The cortical SCN analysis suggested multiple enhanced nodal properties in several brain areas in Ch+ and Ch-compared to HC, mainly in the temporal gyrus, using permutations test and false discovery rate (FDR) (P < 0.05) corrections. Moreover, an increased sigma was found in the Ch + compared with HC (P = 0.0238). The reduced nodal degree (P = 0.0002) and betweenness (P = 0.0008) in the right amygdala of Ch + compared to HC were detected by subcortical SCN analysis. Furthermore, reduced gamma (P = 0.0342) and sigma (P < 0.0001) were found in Ch-compared with HC in the SCN analysis of subfields of the amygdala-hippocampal complex. In the follow-up study, reduced nodal degree (P < 0.0001) was found in the right anterior amygdala, and reduced clustering coefficient and local efficiency were found in patients with LC after the permutation test.

Conclusions

Our study showed GMV defects and structural topological property abnormalities related to LC and chemotherapy. Such morphological changes associated with LC and chemotherapy could be used as imaging markers for clinical assessments and pathological indicators.

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.

The shared genetic etiology of antisocial behavior and psychiatric disorders: Insights from pleiotropy and causality analysis

BACKGROUND

Antisocial behavior (ASB) infringes on the rights of others and significantly disrupts social order. Studies have shown that ASB is phenotypically associated with various psychiatric disorders. However, these studies often neglected the importance of genetic foundations.

METHODS

This study utilized genome-wide association studies and pleiotropy analysis to explore the genetic correlation between ASB and psychiatric disorders. Linkage disequilibrium score regression (LDSC) and high-definition likelihood (HDL) methods were employed to assess genetic correlations, and the PLACO method was used for pleiotropy analysis. Functional annotation and biological pathway analysis of identified pleiotropic genes were performed using enrichment analysis. Furthermore, Mendelian randomization (MR) analysis was conducted to validate these causal relationships.

RESULTS

LDSC and HDL analysis showed that significant positive genetic correlations were between ASB and attention deficit hyperactivity disorder (ADHD), schizophrenia (SCZ), major depressive disorder (MDD), and post-traumatic stress disorder (PTSD). Multiple potential pleiotropic genetic loci were identified, particularly the FOXP2 and MDFIC genes located at the 7q31.1 locus. Enrichment analysis showed that these pleiotropic genes are highly expressed in several brain regions (such as the hypothalamus, cerebellar hemisphere, cortex, and amygdala) and immune-related cells. MR analysis further confirmed the causal effects ADHD, SCZ, and MDD on ASB risk.

CONCLUSION

This study reveals significant genetic correlations and potential causal mechanisms between ASB and various psychiatric disorders. The MR analysis confirmed the causal effects of psychiatric disorders on ASB. These findings deepen our understanding of the genetic architecture of psychiatric disorders and ASB.

Assessment of Prenatal Transportation Stress and Sex on Gene Expression Within the Amygdala of Brahman Calves

As the amygdala is associated with fear and anxiety, it is important to determine the potential effects of gestational stressors on behavior and stress responses in offspring. The objective of this study was to investigate the effects of prenatal transportation stress on amygdala gene expression in 25-day-old Brahman calves, focusing on sex-specific differences. Amygdala tissue samples from prenatally stressed (PNS) and control bull and heifer calves were analyzed using RNA sequencing. A thorough outlier detection process, utilizing visual inspection of multidimensional scaling plots, robust principal component analysis, and PCAGrid methods, led to the exclusion of 5 of 32 samples from subsequent analyses. Differential expression analysis revealed no significant treatment differences between the control and PNS groups within either sex. However, sex-specific differences in gene expression were identified in both the control and PNS groups. The control group showed seven differentially expressed genes between sexes, while ten were identified between PNS males and females, with seven located on the X chromosome. Among these was the ubiquitin-specific peptidase 9 X-linked gene, which plays a role in neurodevelopmental pathways. When comparing males to females, regardless of treatment, a total of 58 genes were differentially expressed, with 45 showing increased expression in females. Gene enrichment analysis indicated that many differentially expressed genes are associated with infectious disease-related pathways. Future research should explore amygdala size and functional responses to various postnatal stimuli.

Functional connectivity of the amygdala subnuclei in various mood states of bipolar disorder

Amygdala functional dysconnectivity lies at the heart of the pathophysiology of bipolar disorder (BD). Recent preclinical studies suggest that the amygdala is a heterogeneous group of nuclei, whose specific connectivity could drive positive or negative emotional valence. We investigated functional connectivity (FC) changes within these circuits emerging from each amygdala's subdivision in 127 patients with BD in different mood states and 131 healthy controls (HC), who underwent resting-state functional MRI. FC was evaluated between lateral and medial nuclei of amygdalae, and key subcortical regions of the emotion processing network: anterior and posterior parts of the hippocampus, and core and shell parts of the nucleus accumbens. FC was compared across groups, and subgroups of patients depending on their mood states, using linear mixed models. We also tested correlations between FC and depression (MADRS) and mania (YMRS) scores. We found no difference between the whole sample of BD patients vs. HC but a significant correlation between MADRS and right lateral amygdala /right anterior hippocampus, right lateral amygdala/right posterior hippocampus and right lateral amygdala/left anterior hippocampus FC (r = -0.44, r = -0.32, r = -0.27, respectively, all pFDR<0.05). Subgroup analysis revealed decreased right lateral amygdala/right anterior hippocampus and right lateral amygdala/right posterior hippocampus FC in depressed vs. non-depressed patients and increased left medial amygdala/shell part of the left nucleus accumbens FC in manic vs non-manic patients. These results demonstrate that acute mood states in BD concur with FC changes in individual nuclei of the amygdala implicated in distinct emotional valence processing. Overall, our data highlight the importance to consider the amygdala subnuclei separately when studying its FC patterns including patients in distinct homogeneous mood states.

Alterations of subcortical structure volume in pediatric bipolar disorder patients with manic or depressive first-episode

BACKGROUND

Bipolar disorder may begin as depression or mania, which can affect the treatment and prognosis. The physiological and pathological differences among pediatric bipolar disorder (PBD) patients with different onset symptoms are not clear. The aims of the present study were to investigate subcortical structural alterations in PBD patients with first-episode depressive (PBD-FED) and first-episode manic (PBD-FEM).

METHODS

A total of 59 individuals including 28 PBD-FED, 13 PBD-FEM, and 18 healthy controls (HCs) underwent high-resolution structural magnetic resonance scans. FreeSurfer 7.2 was used to detect changes in subcortical volumes. Simultaneously, thalamic, hippocampal, and amygdala subregion volumes were compared between the three groups.

RESULTS

Analysis of covariance controlling for age, sex, education, and estimated intracranial volume shows third and fourth ventricle enlargement in patients with PBD. Compared with the PBD-FED and HCs, the PBD-FEM group had reduced gray matter volume in the left thalamus, bilateral hippocampus, and right amygdala. Subsequent subregion analyses showed right cortico-amygdaloid transient, bilateral accessory-basal nucleus, left hippocampal tail, right hippocampal head, and body volume reduction in the PBD-FEM group.

CONCLUSIONS

The present findings provided evidence of decreased subcortical structure in PBD-FEM patients, which might present its trait feature.

Electroencephalographic and Cardiovascular Assessments of Isoflurane-Anesthetized Dogs

This study investigated the use of frontal electroencephalography (EEG) to monitor varying levels of isoflurane anesthesia in dogs. The patient state index (PSI), burst suppression ratio (SR), and waveforms, were continuously recorded while mean arterial blood pressure (MBP), heart rate, responses to electric stimuli, and subjective anesthetic "depth" were assessed every 3 min. At deep anesthesia (2.5× MAC - 3.2%), the PSI (6.5 ± 10.8) and MBP (45.6 ± 16.4 mmHg) were the lowest, and SR was the highest (78.3 ± 24.0%). At 1× MAC (1.3%), the PSI and MBP increased significantly to 47.8 ± 12.6 and 99.8 ± 13.2, respectively, and SR decreased to 0.5 ± 2.5%. The EEG was predominantly isoelectric at 2×-2.5× MAC, indicating unconsciousness and unresponsiveness. As anesthesia lightened, waveforms transitioned to flatter and faster activity patterns with a response to noxious stimuli, suggesting regained consciousness. The PSI and MBP exhibited a stronger correlation (ρ = 0.8098, p = 0.001) than the relationship of PSI with heart rate (ρ = -0.2089, p = 0.249). Five of the six dogs experienced rough recovery, possibly due to high SR and low MBP. These findings suggest that EEG monitoring in dogs can be a valuable tool for the real-time tracking of brain states and can be used to guide the management of isoflurane anesthesia.

Metabolic dysfunction-associated steatotic liver disease is associated with effects on cerebral perfusion and white matter integrity

It is unclear whether early metabolic and inflammatory aberrations in the liver are associated with detrimental changes in brain structure and cognitive function. This cross-sectional study examines putative associations between metabolic dysfunction-associated steatotic liver disease (MASLD) and brain health in 36-55 year-old participants with obesity (n = 70) from the BARICO study (BAriatric surgery Rijnstate and Radboudumc neuroImaging and Cognition in Obesity). The participants underwent brain magnetic resonance imaging to study brain volumes and cortical thickness (3T MRI including T1-weighted magnetization-prepared rapid gradient-echo sequence), cerebral blood perfusion (arterial spin labeling) and white matter integrity (diffusion weighted imaging to assess mean-skeletonized mean diffusivity and fluid-attenuated inversion recovery to detect the presence of white matter hyperintensities (WMH)). The participants additionally performed neuropsychological tests to assess global cognition, working and episodic memory, verbal fluency and the ability to shift attention. Liver biopsies were collected and liver dysfunction was examined with histopathological, biochemical, and gene expression analyses. Linear regression analyses were performed between liver and brain parameters and the influence of body-mass index, diabetes and hypertension was explored. Early stages of liver disease were not associated with cognitive status but with cerebrovascular changes independently of age, sex, BMI, diabetes and hypertension: hepatic fibrosis development was associated with higher spatial coefficient of variation (sCoV) in the nucleus accumbens (NAcc), reflecting greater variations in cerebral perfusion and reduced vascular efficiency. Elevated hepatic levels of free cholesterol and cholesteryl esters were associated with increased WMH, indicating cerebral small vessel disease. RNA-seq and pathway analyses identified associations between sCoV in NAcc and WMH and the expression of hepatic genes involved in inflammation and cellular stress. Additionally, sCoV in NAcc correlated with plasma IL-6 levels suggesting that systemic-low grade inflammation may, at least partly, mediate this relationship. In conclusion, this study demonstrates that specific features of liver dysfunction (e.g. free cholesterol, onset of fibrosis) are associated with subtle cerebrovascular impairments, when changes in cognitive performance are not yet noticeable. These findings highlight the need for future research on therapeutic strategies that normalize metabolic-inflammatory aberrations in the liver to reduce the risk of cognitive decline.

A Cellulose-Rich Diet Disrupts Gut Homeostasis and Leads to Anxiety through the Gut-Brain Axis

It is widely said that a healthy intestinal environment plays an essential role in better mental condition. One known dietary nutrient that maintains the intestinal environment is dietary fiber. A recent study showed that maintaining the intestinal environment with dietary fiber alleviated symptoms of psychiatric disorders in animals. However, such effects have only been reported with soluble fiber, which is highly fermentable and promotes short-chain fatty acid (SCFA) production, and not with insoluble fiber. Therefore, we aimed to verify whether insoluble fiber, such as cellulose, can alter emotion via changes in the gut. We divided mice into two groups and fed either a standard diet (SD, which contains both insoluble and soluble dietary fibers) or a cellulose-rich diet (CRD, which contains cellulose alone as the dietary fibers). We found that CRD-fed mice display increased anxiety-like behavior. CRD-fed animals also showed decreased intestinal SCFA levels along with increased intestinal permeability, dysmotility, and hypersensitivity. This behavioral and physiological effect of CRD has been completely abolished in vagotomized mice, indicating the direct link between intestinal environment exacerbation to the emotion through the gut-brain axis. Additionally, we found that amygdalar dopamine signaling has been modified in CRD-fed animals, and the opioid antagonist abolished this dopaminergic modification as well as CRD-induced anxiety. Altogether, our findings indicate that consumption of cellulose alone as the dietary fiber may evoke intestinal abnormalities, which fire the vagus nerve, then the opioidergic system, and amygdalar dopamine upregulation, resulting in the enhancement of anxiety.

Looking Back to Move Forward: Research in Stress, Behavior, and Immune Function

BACKGROUND

From the original studies investigating the effects of adrenal gland secretion to modern high-throughput multidimensional analyses, stress research has been a topic of scientific interest spanning just over a century.

SUMMARY

The objective of this review was to provide historical context for influential discoveries, surprising findings, and preclinical models in stress-related neuroimmune research. Furthermore, we summarize this work and present a current understanding of the stress pathways and their effects on the immune system and behavior. We focus on recent work demonstrating stress-induced immune changes within the brain and highlight studies investigating stress effects on microglia. Lastly, we conclude with potential areas for future investigation concerning microglia heterogeneity, bone marrow niches, and sex differences.

KEY MESSAGES

Stress is a phenomenon that ties together not only the central and peripheral nervous system, but the immune system as well. The cumulative effects of stress can enhance or suppress immune function, based on the intensity and duration of the stressor. These stress-induced immune alterations are associated with neurobiological changes, including structural remodeling of neurons and decreased neurogenesis, and these contribute to the development of behavioral and cognitive deficits. As such, research in this field has revealed important insights into neuroimmune communication as well as molecular and cellular mediators of complex behaviors relevant to psychiatric disorders.

How the arts heal: a review of the neural mechanisms behind the therapeutic effects of creative arts on mental and physical health

Background

The creative arts have long been known for their therapeutic potential. These modalities, which include dance, painting, and music, among others, appear to be effective in enhancing emotional expression and alleviating adverse physiological and psychological effects. Engagement in creative arts can be pursued as a personal hobby, in a classroom setting, or through a formal therapeutic intervention with a qualified therapist. Engagement can be active (i.e., creating) or passive (i.e., viewing, listening). Regardless of the modality and manner of engagement, the mechanisms explaining the therapeutic efficacy of creative arts remain poorly understood.

Objective

This study aims to systematically review research investigating the neurological mechanisms activated during active or passive engagement in creative arts, with a specific emphasis on the roles of the medial prefrontal cortex (mPFC) and the amygdala in emotional regulation (ER) and creative behaviors. The review seeks to provide preliminary evidence for the possible existence of common neural mechanisms underlying both phenomena, which could inform the development of targeted therapeutic interventions leveraging creative arts for ER.

Methods

A systematic review was conducted following the Cochrane Collaboration guideline and PRISMA standards to identify studies examining the neurological mechanisms underlying creative activities.

Results

A total of six out of 85 records meet the inclusion criteria, with all being basic research studies. Preliminary findings suggest that active and passive engagement with creative arts consistently activate neural circuits implicated in adaptive emotional regulation, including the mPFC and amygdala. These activations mirror the neural pathways engaged in effective ER strategies, suggesting the possible existence of shared mechanisms between creative expression and emotional processing.

Conclusion

The evidence underscores the potential of creative arts as a complementary therapeutic strategy alongside conventional care and other evidence-based mind-body modalities. By elucidating the shared neural mechanisms between creative arts engagement and ER, this review contributes to the theoretical and practical understanding of the role of creative arts in mental health. Future research is recommended to further explore these neural correlations and their implications for therapeutic practice.

Alterations in GABAA receptor-mediated inhibition triggered by status epilepticus and their role in epileptogenesis and increased anxiety

The triggers of status epilepticus (SE) in non-epileptic patients can vary widely, from idiopathic causes to exposure to chemoconvulsants. Regardless of its etiology, prolonged SE can cause significant brain damage, commonly resulting in the development of epilepsy, which is often accompanied by increased anxiety. GABAA receptor (GABAAR)-mediated inhibition has a central role among the mechanisms underlying brain damage and the ensuing epilepsy and anxiety. During SE, calcium influx primarily via ionotropic glutamate receptors activates signaling cascades which trigger a rapid internalization of synaptic GABAARs; this weakens inhibition, exacerbating seizures and excitotoxicity. GABAergic interneurons are more susceptible to excitotoxic death than principal neurons. During the latent period of epileptogenesis, the aberrant reorganization in synaptic interactions that follow interneuronal loss in injured brain regions, leads to the formation of hyperexcitable, seizurogenic neuronal circuits, along with disturbances in brain oscillatory rhythms. Reduction in the spontaneous, rhythmic "bursts" of IPSCs in basolateral amygdala neurons is likely to play a central role in anxiogenesis. Protecting interneurons during SE is key to preventing both epilepsy and anxiety. Antiglutamatergic treatments, including antagonism of calcium-permeable AMPA receptors, can be expected to control seizures and reduce excitotoxicity not only by directly suppressing hyperexcitation, but also by counteracting the internalization of synaptic GABAARs. Benzodiazepines, as delayed treatment of SE, have low efficacy due to the reduction and dispersion of their targets (the synaptic GABAARs), but also because themselves contribute to further reduction of available GABAARs at the synapse; furthermore, benzodiazepines may be completely ineffective in the immature brain.

Comparison of Resting-State Functional Connectivity Between Generalized Anxiety Disorder and Social Anxiety Disorder: Differences in the Nucleus Accumbens and Thalamus Network

Background: Generalized anxiety disorder (GAD) and social anxiety disorder (SAD) are distinguished by whether anxiety is limited to social situations. However, reports on the differences in brain functional networks between GAD and SAD are few. Our objective is to understand the pathogenesis of GAD and SAD by examining the differences in resting brain function between patients with GAD and SAD and healthy controls (HCs). Methods: This study included 21 patients with SAD, 17 patients with GAD, and 30 HCs. Participants underwent psychological assessments and resting-state functional magnetic resonance imaging. Whole-brain analyses were performed to compare resting-state functional connectivity (rsFC) among the groups. In addition, logistic regression analysis was conducted on the rsFC to identify significant differences between GAD and SAD. Results: Patients with SAD and GAD had significantly higher rsFC between the bilateral postcentral gyri and bilateral amygdalae/thalami than HCs. Compared with patients with SAD, those with GAD had significantly higher rsFC between the right nucleus accumbens and bilateral thalami and between the left nucleus accumbens and right thalamus. rsFC between the left nucleus accumbens and right thalamus positively correlated with state anxiety in patients with SAD and GAD, respectively. In addition, logistic regression analysis revealed that the right nucleus accumbens and the right thalamus connectivity could distinguish SAD from GAD. Conclusions: GAD and SAD were distinguished by the right nucleus accumbens and the right thalamus connectivity. Our findings offer insights into the disease-specific neural basis of SAD and GAD. Clinical Trial Registration Number: UMIN000024087. Impact Statement This study is the first to identify a resting state functional connectivity that distinguishes social anxiety disorder (SAD) from generalized anxiety disorder (GAD) and to clarify a common connectivity in both disorders. We found that the connectivity between the right nucleus accumbens and the right thalamus differentiated SAD from GAD. Furthermore, these rsFC differences suggest an underlying basis for fear overgeneralization. Our findings shed light on the pathophysiology of these conditions and could be used as a basis for further studies to improve outcomes for such patients.

Excitatory synaptic structural abnormalities produced by templated aggregation of α-syn in the basolateral amygdala

Parkinson's disease (PD) and Dementia with Lewy bodies (DLB) are characterized by neuronal α-synuclein (α-syn) inclusions termed Lewy Pathology, which are abundant in the amygdala. The basolateral amygdala (BLA), in particular, receives projections from the thalamus and cortex. These projections play a role in cognition and emotional processing, behaviors which are impaired in α-synucleinopathies. To understand if and how pathologic α-syn impacts the BLA requires animal models of α-syn aggregation. Injection of α-syn pre-formed fibrils (PFFs) into the striatum induces robust α-syn aggregation in excitatory neurons in the BLA that corresponds with reduced contextual fear conditioning. At early time points after aggregate formation, cortico-amygdala excitatory transmission is abolished. The goal of this project was to determine if α-syn inclusions in the BLA induce synaptic degeneration and/or morphological changes. In this study, we used C57BL/6 J mice injected bilaterally with PFFs in the dorsal striatum to induce α-syn aggregate formation in the BLA. A method was developed using immunofluorescence and three-dimensional reconstruction to analyze excitatory cortico-amygdala and thalamo-amygdala presynaptic terminals closely juxtaposed to postsynaptic densities. The abundance and morphology of synapses were analyzed at 6- or 12-weeks post-injection of PFFs. α-Syn aggregate formation in the BLA did not cause a significant loss of synapses, but cortico-amygdala and thalamo-amygdala presynaptic terminals and postsynaptic densities with aggregates of α-syn show increased volumes, similar to previous findings in human DLB cortex, and in non-human primate models of PD. Transmission electron microscopy showed that asymmetric synapses in mice with PFF-induced α-syn aggregates have reduced synaptic vesicle intervesicular distances, similar to a recent study showing phospho-serine-129 α-syn increases synaptic vesicle clustering. Thus, pathologic α-syn causes major alterations to synaptic architecture in the BLA, potentially contributing to behavioral impairment and amygdala dysfunction observed in synucleinopathies.

Acupuncture modulates emotional network resting-state functional connectivity in patients with insomnia disorder: a randomized controlled trial and fMRI study

BACKGROUND

Insomnia disorder (ID) is one of the most common sleep problems, usually accompanied by anxiety and depression symptoms. Functional magnetic resonance imaging (fMRI) study suggests that both poor sleep quality and negative emotion are linked to the dysregulation of brain network related to emotion processing in ID patients. Acupuncture therapy has been proven effective in improving sleep quality and mood of ID patients, but the involved neurobiological mechanism remains unclear. We aimed to investigate the modulation effect of acupuncture on resting-state functional connectivity (rsFC) of the emotional network (EN) in patients experiencing insomnia.

METHODS

A total of 30 healthy controls (HCs) and 60 ID patients were enrolled in this study. Sixty ID patients were randomly assigned to real and sham acupuncture groups and attended resting-state fMRI scans before and after 4 weeks of acupuncture treatment. HCs completed an MRI/fMRI scan at baseline. The rsFC values within EN were calculated, and Hamilton Anxiety Scale (HAMA), Hamilton Depression Scale (HAMD), Pittsburgh Sleep Quality Index (PSQI), Hyperarousal Scale (HAS), and actigraphy data were collected for clinical efficacy evaluation.

RESULTS

Resting-state FC analysis showed abnormalities in rsFC centered on the thalamus and dorsolateral prefrontal cortex within EN of ID patients compared to HCs. After real acupuncture treatment, rsFC of the anterior cingulate cortex, hippocampus, and amygdala were increased compared with the sham acupuncture group (p < 0.05, FDR corrected). In real acupuncture group, the rsFC value was decreased between left amygdala and left thalamus after 4 weeks of treatment compared with baseline. A trend of correlation was found that the increased rsFC value between the right amygdala and left hippocampus was positively correlated with the decreased HAMA scores across all ID patients, and the decreased left amygdala rsFC value with the left thalamus was negatively correlated with the increased sleep efficiency in the real acupuncture group.

CONCLUSION

Our findings showed that real acupuncture could produce a positive effect on modulating rsFC within network related to emotion processing in ID patients, which may illustrate the central mechanism underlying acupuncture for insomnia in improving sleep quality and emotion regulation.

TRIAL REGISTRATION

http://www.chictr.org.cn ., ChiCTR1800015282, 20/03/2018.