Neurotrophic factors and neuroplasticity pathways in the pathophysiology and treatment of depression

Physical exercise ameliorates pain, mood alterations and neuroinflammation in a murine model of osteoarthritis

Osteoarthritis (OA) is largely associated with chronic pain, and it is a social and economic problem worldwide. OA pain can lead to psychiatric symptom onset, such as anxiety and depression. Emerging evidence suggest neuroinflammation as a common denominator between OA pain and mood disorders. OA pain pharmacological strategies are often ineffective or cause side effects, therefore, identifying novel non-pharmacological therapeutic approaches, like diet and exercise, could be important. Here, using 8-month-old male C57BL/6 J mice, we evaluated the effect of regular physical exercise on OA pain and related comorbidities. OA was induced by monoiodoacetate-(MIA) administration in knee joint in mice that had undergone physical exercise-(PE) or a sedentary lifestyle-(SL) for two months. After OA induction, mice continued the exercise/not-exercise protocol for another month and subsequently all animals were sacrificed. An in-depth biochemical evaluation (RT-qPCR) was performed at the level of the knee joint, sciatic nerve, dorsal root ganglia, spinal cord and brain areas (brainstem, hypothalamus and hippocampus) and myenteric plexus to evaluate the effect of both OA and exercise on (neuro)inflammation in regions involved in pain and mood regulation. Throughout the experimental protocol, pain-like behavior and motor performance were evaluated, and before sacrifice, mood alterations and metabolic changes were also assessed. Our results showed that OA_SL mice exhibit painful symptoms and mood disturbances. These alterations were also associated with (neuro)inflammation. PE mitigates pain-like behavior and mood alterations and reduces (neuro)inflammation, suggesting that a healthy and active lifestyle may have a positive impact in preventing and/or counteracting OA onset and related comorbidities.

Exploring the neuroplasticity hypothesis in depression: The role of traditional Chinese herbal medicine

BACKGROUND

Depression is a mental disorder that seriously affects global health, and its pathogenesis involves multiple factors, including changes in neuroplasticity. The neuroplasticity hypothesis suggests that there may be functional and structural abnormalities in synaptic plasticity, neuronal generation and maturation, neural circuits and related signaling pathways in patients with depression. Traditional Chinese medicine (TCM), as a traditional treatment method, has attracted increasing attention in the field of neuropharmacology in recent years due to its high efficiency and low toxicity.

PURPOSE

This article will systematically review the neuroplasticity changes in key brain regions and related mechanisms of depression, with a focus on the recent research progress in traditional Chinese herbal medicine intervention on neuroplasticity, to provide new ideas and strategies for the treatment of depression.

METHODS

To investigate the effects and mechanisms of Chinese herbal medicine's antidepressant actions through promoting neuroplasticity, data were collected from CNKI, Web of Science, PubMed, and ScienceDirect through November 2024. In addition, a classification and summary of Chinese herbal medicine to restore neuroplasticity was performed.

RESULTS

Brain regions such as the hippocampus, prefrontal cortex, and amygdala are closely associated with neuroplasticity in depression. Moreover, the glutamatergic system, neurotrophic factors, monoamine neurotransmitters, and neuroinflammation are the main mechanisms that regulate neuroplasticity. The benefits of extracts, active ingredients, and formulas of Chinese herbal medicine on neuroplasticity through multiple pathways have been widely reported.

CONCLUSION

The enhancement of neuroplasticity and regulation of its endogenous molecular pathways offer novel therapeutic paradigms for employing botanical interventions in depression management. Future investigations should prioritize mechanistic exploration through integrated preclinical-clinical approaches to elucidate how Chinese herbal formulations modulate neuroplasticity, which decipher the multi-target pharmacological actions underlying botanical antidepressants' therapeutic efficacy.

NRXN3-NLGN1 complex influences the development of depression induced by maternal separation in rats

Early-life stress (ELS) increases the risk of major depressive disorder in children and adolescents. However, the molecular and cellular mechanisms of major depressive disorder (MDD) induced by ELS are poorly understood. Here, we establish a stress model in rats in which maternal separation stress (MS) during the postnatal period increases susceptibility to restraint stress (RS) later in life. In terms of mechanism, MS causes long-lasting synaptic plasticity alterations in rats, which is accompanied by reduced branch and spine lengths in the hippocampus. We identified the role of the cell adhesion factor neurexin 3 (NRXN3) and its ligand neuroligin 1 (NLGN1) as mediators of these effects. NRXN3 and NLGN1 downregulation in the hippocampus occurred prior to the observed synaptic changes and depression-related behaviors. In conclusion, NRXN3 is involved in the development of depression induced by maternal separation, and the specific mechanism involves the NRXN3-NLGN1 complex, which can mediate synaptic plasticity and increase susceptibility todepression.

Acute carbamoylated erythropoietin reduces social stress-induced anxiety and depression-related behaviors

The hormone and trophic factor Erythropoietin (EPo) promotes red blood cell production and has neurotrophic effects, modulating behavior and promoting neural plasticity, like neurogenesis. Modifying EPo by attaching a carbamoyl group (cEPo) results in similar neuronal effects without erythropoietic actions. We hypothesize that neuroplastic and learning effects of cEPo may be dependent on its action in dorsal dentate gyrus of the hippocampus, where neurogenesis occurs. The Stress Alternatives Model (SAM), a 4-day social stress and decision-making paradigm with a large novel aggressor, that provides opportunities to avoid interaction via escape routes. Early, male test mice display stable Escape (avoiding aggression) or Stay (acquiescence to aggressor) behavioral phenotypes. In these studies, mice were given a single intracerebroventricular (icv; 100 ng), or single intra-dentate gyrus (iDG; 10 ng) injection of cEPo or vehicle. By Day 4, 30% of icv cEPo treated mice and 37.5% of iDG cEPo treated mice reversed their phenotype (Stay to Escape). Mice receiving vehicle injections did not change. Normalization of social preference, and reduction in fear freezing behavior, after cEPo treatment, coincide with transcriptional changes of orexin receptors (Hcrtr1 &Hcrtr2) in the hippocampus, including phenotype- and treatment-dependent alterations in learning-associated molecular signaling molecules. Hippocampal Hcrtr1 moderately colocalize with EPo receptors (Epor) in the dentate gyrus, while Hcrtr2 is expressed with Epor in CA1. Anxiolytic actions of cEPo during social interaction indicate mechanisms that influence learning in stressful situations, suggesting that cEPo may be a novel agent for treatment of comorbid conditions related to anxiety, depression, and PTSD.

Investigating acupuncture therapy in depression: mechanisms of synaptic plasticity regulation

Depression is a severe heterogeneous mental illness that is highly co-morbid with other mental and somatic disorders. It poses a significant healthcare burden on both individuals and society. Currently, the use of single-target antidepressants exhibits suboptimal efficacy with significant adverse effects. Acupuncture has been advocated as a practical and effective treatment for depression, due to its low adverse effects rate compared to antidepressant medication. Currently, several studies have shown that acupuncture treatment for depression primarily involves multiple therapeutic mechanisms, including the regulation of specific gene expression, neuropeptide and neurotransmitter release, increasing the expression of neurotrophic factors, suppressing hyperactivity of the hypothalamic-pituitary-adrenal (HPA) axis, attenuating inflammatory responses, and restoring gut microbiota balance. These therapeutic effects involve the regulation of critical signaling pathways, including the cAMP-responsive element binding protein (CREB) signaling pathway, mitogen-activated protein kinases (MAPK) signaling pathway, mechanistic target of rapamycin (mTOR) signaling pathway, and toll-like receptors (TLR) signaling pathway. Notably, depression-associated molecular mechanisms and signaling pathway dysregulations are closely linked to impaired neural and synaptic plasticity. Acupuncture synergistically modulates the neuro-immune-microbiome multidimensional network and integrates crosstalk among key pathways such as CREB, thereby systemically restoring synaptic plasticity. This multi-dimensional integrative mechanism likely underlies its therapeutic superiority over single-target antidepressants. This review aims to elucidate how acupuncture restores cerebral synaptic plasticity by rectifying depression-related systemic dysfunctions and signaling pathway abnormalities, which will advance our understanding of its regulatory potential in depression treatment and inform the development of precision therapeutic strategies.

Phytochemicals encouraging neurotrophic pathways: brain-derived neurotrophic factors as molecular targets in depression

A complex neuropsychiatric disorder, major depressive disorder (MDD), is linked to dysregulation of neurotrophic factors, neurotransmitter imbalances, and structural changes in the brain. A lack of brain-derived neurotrophic factor (BDNF) has been linked to the pathophysiology of depression. BDNF is critical for neuroplasticity, neuronal viability, and synaptic efficacy. The neurotrophic hypothesis of depression proposes that treatment strategies targeting the BDNF signaling pathway may be promising therapeutic strategies. While traditional antidepressants such as selective serotonin reuptake inhibitors (SSRIs) are known to modulate the expression of BDNF, their use is limited in effectiveness, and a delayed onset of action occurs in many patients. Recent studies have focused on the possibility of the use of phytochemicals as antidepressant agents to target the BDNF pathway. Phytochemicals such as curcumin, resveratrol, quercetin, EGCG, hesperidin, and baicalin have demonstrated neuroprotective and antidepressant-like properties by modulating several key signaling pathways, including the PI3K/Akt/mTOR, MAPK/ERK, and NF-κB/CREB pathways. These compounds increase BDNF expression, promote synaptic plasticity, and mitigate neuroinflammation, contributing to improved mood and cognitive function. Although phytochemicals show considerable preclinical and clinical activity, their clinical usage is limited and characterized by several problems, such as poor bioavailability, poor blood‒brain barrier permeability, and variability in therapeutic response. Several formulation strategies, such as structural modifications and nanoencapsulation, are being explored to improve their pharmacokinetic profiles. These results also highlight the need for larger clinical trials, combination therapies with pharmaceuticals, and mechanistic studies that may clarify the role of phytochemicals in establishing these products as effective and well-tolerated treatments for depression. This narrative review addresses the gap in understanding how plant-derived bioactive compounds can modulate neurotrophic pathways in depression and explores emerging strategies for translating these findings into therapies.

Berberine: An isoquinoline alkaloid targeting the oxidative stress and gut-brain axis in the models of depression

Depression seriously affects people's quality of life, and there is an urgent need to find novel drugs to cure treatment-resistant depression. Berberine (BBR), extracted from Coptis chinensis Franch., Phellodendron bark, Berberis vulgaris, and Berberis petiolaris, could be a potential multi-target drug for depression. To summarize the effects of BBR on depression in terms of in vitro or in vivo experiments, we searched electronic databases, such as PubMed, Web of Science, Google Scholar, Wanfang Database, and China National Knowledge Infrastructure, from inception until May 2024. Then, we summarize that BBR has indirect antidepressant properties to improve depressive symptoms, manifesting in modulating the gut microbial community, strengthening the intestinal barrier, increasing the abundance of short-chain fatty acid-producing bacteria, and regulating tryptophan metabolism. BBR also exerts antidepressant-like effects via remodulating nuclear factor-erythroid 2-related factor 2/antioxidant response element pathway, hypothalamic-pituitary-adrenal axis, and peroxisome proliferators-activated receptor-delta. Nevertheless, further clinical trials and more high-quality animal studies are needed to show the actual clinical value of BBR for depression.

A Methodological Evaluation of Four Different Paired Associative Stimulation Paradigms in Healthy Controls

Background/Objectives: Plasticity deficits play a key role in the pathophysiology of various psychiatric and neurological disorders. Paired associative stimulation (PAS) leverages Hebbian principles to induce synaptic plasticity in the human brain. By repeatedly pairing (1) the peripheral nerve stimulation of the median nerve with (2) transcranial magnetic stimulation over the primary motor cortex (M1) at different inter-stimulus intervals (25 ms; PAS-25, or 10 ms; PAS-10), corticospinal excitability can be increased (PAS-25, mimicking long-term potentiation (LTP)) or decreased (PAS-10, mimicking long-term depression (LTD)). However, variations in the number of pairings and inter-pair intervals lack consensus. The aim of the study was to evaluate four different PAS paradigms, i.e., PAS-10 and PAS-25 with both 180 versus 225 pairings each, to establish the most reliable PAS protocols for LTP- and LTD-like cortical changes. Methods: In a randomized, double-blind, crossover study, 14 healthy participants underwent PAS-10 and PAS-25 with 180 and 225 pairings. Excitability was assessed by quantifying the EMG response amplitude of a hand muscle to a single stimulus. Results: PAS-25 with 225 pairings produced a robust enhancement of corticospinal excitability, while PAS-25 with 180 pairings was less effective. Surprisingly, PAS-10 with both 180 and 225 pairings also increased excitability. Conclusions: While all four PAS paradigms enhanced M1 excitability, PAS-25 with 225 pairings induced the strongest group-level effects and was most time-efficient. Significant individual variability of PAS responses suggests that optimizing PAS parameters, including pairing number and interstimulus intervals, may be necessary for personalized approaches.

Metabolic Signalling Peptides and Their Relation to Clinical and Demographic Characteristics in Acute and Recovered Females with Anorexia Nervosa

Background/Objectives: Recent research has established that metabolic factors may increase the vulnerability to develop anorexia nervosa (AN). The aim of this study was to explore the serum concentrations of leptin, insulin-like growth factor-1 (IGF-1), insulin and insulin receptor substrate (IRS-1) as possible state or trait biomarkers for AN in the acute and recovery (recAN) phases. Our secondary aim was to test associations between the tested markers and demographic and clinical characteristics. Methods: This cross-sectional study included data from 56 participants with AN, 24 recAN participants and 51 healthy controls (HCs). Enzyme-linked immunosorbent assays (ELISAs) were used to quantify serum concentrations of leptin, IGF-1, insulin and IRS-1. An analysis of covariance (ANCOVA) and linear regression models were utilised to test our results. Results: There were significant differences with a large effect size between the groups for serum leptin (p < 0.001; d = 0.80), whereby people with AN had lower leptin than those with recAN (p = 0.023; d = 0.35) and HCs (p < 0.001; d = 0.74). The between-group comparison of IGF-1 did not reach significance, although the effect size was moderate (d = 0.6) and was driven by lower levels of IGF-1 in people with acute AN compared to HCs (p = 0.036; d = 0.53). Serum insulin and IRS-1 did not differ between groups. Conclusions: Low leptin levels seen in individuals with AN may be due to starvation leading to fatty tissue depletion. Understanding the regulation of IGF-1 and insulin signalling over the course of the disorder requires further investigation.

The effects of exercise interventions on depressive symptoms in stroke patients: a systematic review and meta-analysis

Purpose

This systematic review and meta-analysis aimed to evaluate the effects of exercise interventions on depressive symptoms in stroke patients.

Methods

Following PRISMA guidelines, We conducted searches in PubMed, Embase, CENTRAL, and Web of Science. The topic was the effect of exercise on depression levels in stroke patients. Patient's performance on depression scales after exercise was assessed using standardized mean difference (SMD) and 95% confidence intervals (95% CI). A random effects model (RE) was used to conduct a meta-analysis and compare the results between subgroups conducted based on adherence to ACSM guidelines and the length of exercise interventions.

Results

The analysis included 24 randomized controlled trials (RCTs) involving 1,757 participants. The meta-analysis revealed that exercise interventions had a significant positive effect on reducing depressive symptoms in stroke patients, with a standardized mean difference (SMD) of -0.43 (95% CI: 0.65, -0.21). Subgroup analysis indicated that high compliance with ACSM guidelines resulted in a more substantial reduction in depressive symptoms (SMD = -0.79, 95% CI: 1.10, -0.49), compared with low or uncertain compliance (SMD = -0.03, 95% CI: 0.16, 0.10). Longer exercise intervention was associated with greater mitigation of depressive symptoms. The differences between intervention groups of different lengths were statistically significant (p < 0.05).

Conclusion

These findings support the integration of tailored exercise programs into post-stroke care to optimize mental health outcomes. Compliance to ACSM-recommended exercise dosages significantly ameliorate depression levels in stroke patients. Further research is warranted to explore standardized exercise regimens in larger, multicenter trials.

Systematic Review Registration

https://www.crd.york.ac.uk/prospero/#recordDetails, identifier PROSPERO(CRD42024579095).

Abnormal neuritic microstructures in the anterior limb of internal capsules in treatment-resistant depression - A cross-sectional NODDI study

BACKGROUND

Microstructural deficits of brain tissue are implicated in the pathophysiology of major depressive disorder (MDD). Recent studies have highlighted the neurotrophic mechanisms underlying effective treatments such as ketamine for treatment-resistant depression (TRD). However, little is known about microstructural changes in TRD. Neurite orientation dispersion and density imaging (NODDI) has enabled in vivo investigation of gray matter (GM) and white matter (WM) microstructure. This study sought to examine microstructural abnormalities in gray and white matter in patients with TRD using NODDI.

METHODS

This study compared the neurite density index (NDI) and orientation dispersion index (ODI) of neurites in 70 patients with TRD and 35 healthy controls. We fitted separate optimal NODDI models for gray and white matter. The locations of microstructural deficit were identified using region-based and voxel-based analysis. The affected white matter fibers were tracked with correlational tractography analysis.

RESULTS

An increase of ODI at the middle to the ventral part of the right anterior limb of the internal capsule (ALIC) was observed in patients with TRD compared with healthy controls. The quantitative anisotropy of frontothalamic fibers passing through the ALIC negatively correlated with the ODI increase in the TRD group.

CONCLUSION

The microstructural disorganization of the frontothalamic pathway could be linked to the pathophysiology and individual heterogeneity of TRD.

miRNAs in Major Depression: Possible Association of miR-17 and miR-92 with Childhood Traumas

Objective

Psychosocial and genetic factors are considered to play roles in the etiological mechanisms of major depressive disorder (MDD). The involvement of miRNAs in the etiopathogenesis of depression and childhood traumas is still unclear. This study aims to reveal potential differences in miRNA levels between patients with depression and healthy individuals and assess their connection to childhood traumas.

Methods

This study included fifty patients with MDD and 33 healthy controls. The targeting of the 3'UTR regions of the BDNF, SLC6A4/SERT/5-HTT, HTR1a, and HTR2a genes by 8 miRNAs was analyzed to explore their potential involvement in depression and childhood traumas. The Hamilton Depression Rating Scale, the Hamilton Anxiety Rating Scale, and the Childhood Trauma Questionnaire-28 were administered to the participants.

Results

Patients with MDD exhibited significantly lower expression levels of miR-335 and miR-4775, as well as significantly higher expression levels of miR-15, miR-16, miR-17, miR-92, miR-182, and miR-206, when compared to healthy controls using the 2-(ΔΔCt) method. Only miR-17 and miR-92 were associated with childhood traumas in the patients with depression.

Conclusion

Our research reveals a possible involvement of miRNAs in the pathophysiology of depression and highlights a potential relationship between childhood traumas and specific miRNAs in depressed patients.

Physical activity and neuroplasticity in neurodegenerative disorders: a comprehensive review of exercise interventions, cognitive training, and AI applications

This review aimed to elucidate the mechanisms through which (i) physical activity (PA) enhances neuroplasticity and cognitive function in neurodegenerative disorders, and (ii) identify specific PA interventions for improving cognitive rehabilitation programs. We conducted a literature search in PubMed, Medline, Scopus, Web of Science, and PsycINFO, covering publications from January 1990 to August 2024. The search strategy employed key terms related to neuroplasticity, physical exercise, cognitive function, neurodegenerative disorders, and personalized physical activity. Inclusion criteria included original research on the relationship between PA and neuroplasticity in neurodegenerative disorders, while exclusion criteria eliminated studies focusing solely on pharmacological interventions. The review identified multiple pathways through which PA may enhance neuroplasticity, including releasing neurotrophic factors, modulation of neuroinflammation, reduction of oxidative stress, and enhancement of synaptic connectivity and neurogenesis. Aerobic exercise was found to increase hippocampal volume by 1-2% and improve executive function scores by 5-10% in older adults. Resistance training enhanced cognitive control and memory performance by 12-18% in elderly individuals. Mind-body exercises, such as yoga and tai-chi, improved gray matter density in memory-related brain regions by 3-5% and enhanced emotional regulation scores by 15-20%. Dual-task training improved attention and processing speed by 8-14% in individuals with neurodegenerative disorders. We also discuss the potential role of AI-based exercise and AI cognitive training in preventing and rehabilitating neurodegenerative illnesses, highlighting innovative approaches to personalized interventions and improved patient outcomes. PA significantly enhances neuroplasticity and cognitive function in neurodegenerative disorders through various mechanisms. Aerobic exercise, resistance training, mind-body practices, and dual-task exercises each offer unique cognitive benefits. Implementing these activities in clinical settings can improve patient outcomes. Future research should focus on creating personalized interventions tailored to specific conditions, incorporating personalized physical exercise programs to optimize cognitive rehabilitation.

The Impact of Walking on BDNF as a Biomarker of Neuroplasticity: A Systematic Review

BACKGROUND/OBJECTIVES

The brain-derived neurotrophic factor (BDNF) is a critical exercise-induced modulator of various neuroplasticity processes, including adult hippocampal neurogenesis. Environmental affordance for physical activity is a novel theory that aims to increase the BDNF through walking or climbing stairs, stimulated by the urban and interior environment. In a systematic review, this paper explores the association between walking, as a structured or free-living form of physical activity, and changes in the BDNF in humans with healthy locomotion.

METHOD

A systematic review with a registered protocol, INPLASY2024110093, and following the PRISMA guidelines, includes English-language original research articles on adult and older adult human subjects who are locomotor-healthy, studies on walking as a structured exercise or free-living physical activity that is presented in a non-combined intervention, and must report changes in the BDNF as a dependent variable. The search was conducted using three databases: PubMed, Web of Science, and Scopus, resulting in 21 eligible studies.

RESULTS

This systematic review finds that the impact of walking on the BDNF is evidenced, but subject to moderate to high intensities in single bouts. At the same time, the long-term effects are yet to be fully understood, potentially due to the uptake of the BDNF for functional brain improvements, neuroplasticity processes, or muscle repair, instead of an accumulation of the BDNF itself, yet still confirm the important role of the BDNF for neurosustainability. Age and environmental factors such as heat are also found to affect the increase in the BDNF. The narrative synthesis provides elaborate explanations for understanding those complex dynamics before reaching future conclusions on the impact of walking or environmental affordance for physical activity on the changes in the BDNF concentrations.

CONCLUSIONS

This systematic review highlights the potential role played by moderate- and high-intensity walking as a lifestyle intervention that can be utilised through the built environment to promote adaptive brain changes, through the sustainable regulation of the BDNF.

The associations of brain-derived neurotrophic factor (BDNF) levels with psychopathology and lipid metabolism parameters in adolescents with major depressive disorder

Brain-derived neurotrophic factor (BDNF) is crucial for the growth, differentiation and maintenance of neuronal systems, which is closely associated with major depressive disorder (MDD). The objective of this study was to investigate the BDNF levels and their associations with psychopathology and lipid metabolism parameters in adolescents with MDD. From January to December 2021, the study included 141 adolescents with MDD and 90 healthy controls (HCs). The Center for Epidemiological Studies Depression Scale (CES-D), the Insomnia Severity Index Scale (ISI), the Epworth Sleepiness Scale (ESS) and the Positive and Negative Suicidal Ideation Scale (PANSI) were used to assess depressive symptoms, insomnia, excessive daytime sleepiness, and suicidal ideation, respectively. BDNF levels and lipid metabolism parameters were also measured. Compared to HCs, adolescents with MDD had significantly lower BDNF levels (p < 0.001). In patients, BDNF levels were positively correlated with age, BMI, total cholesterol (TC), high-density lipoprotein cholesterol (HDL-C) and low-density lipoprotein cholesterol (LDL-C); and negatively correlated with the scores of CES-D and ISI (all p < 0.05). The results of the multivariate linear regression analyses indicated that BDNF levels were positively associated with age (β = 0.198, t = 2.447, p = 0.016), first-episode MDD (β = 0.176, t = 2.234, p = 0.027) and TC level (β = 0.240, t = 3.048, p = 0.003), and negatively associated with the scores of ESS (β = -0.171, t = -2.203, p = 0.029) and ISI (β = -0.231, t = -2.996, p = 0.003). Of note, the associations between BDNF and psychopathology were observed only in female and first-episode patients. BDNF levels were decreased in adolescents with MDD. Patients with low BDNF levels were in a more severe psychiatric state and had changes in lipid metabolism parameters. This study provided preliminary evidence that BDNF may play a role in the onset and progression of MDD.

Optogenetics and chemogenetics: key tools for modulating neural circuits in rodent models of depression

Optogenetics and chemogenetics are emerging neuromodulation techniques that have attracted significant attention in recent years. These techniques enable the precise control of specific neuronal types and neural circuits, allowing researchers to investigate the cellular mechanisms underlying depression. The advancement in these techniques has significantly contributed to the understanding of the neural circuits involved in depression; when combined with other emerging technologies, they provide novel therapeutic targets and diagnostic tools for the clinical treatment of depression. Additionally, these techniques have provided theoretical support for the development of novel antidepressants. This review primarily focuses on the application of optogenetics and chemogenetics in several brain regions closely associated with depressive-like behaviors in rodent models, such as the ventral tegmental area, nucleus accumbens, prefrontal cortex, hippocampus, dorsal raphe nucleus, and lateral habenula and discusses the potential and challenges of optogenetics and chemogenetics in future research. Furthermore, this review discusses the potential and challenges these techniques pose for future research and describes the current state of research on sonogenetics and odourgenetics developed based on optogenetics and chemogenetics. Specifically, this study aimed to provide reliable insights and directions for future research on the role of optogenetics and chemogenetics in the neural circuits of depressive rodent models.

Adolescent social isolation induces sex-specific behavioral and neural alterations

Adversities associated with isolation during adolescence, including the lack of appropriate emotional and social experiences, can jeopardize the individual development leading to the onset of mental illnesses such as major depressive disorder. Girls have higher rates of depression compared to boys; however, the relative contribution of biological and cultural factors to such a gender-dependent difference remains unclear. To identify the role of biological factors in this distinct susceptibility, we exposed adolescent C57BL/6 male and female mice (n = 12-14) to social isolation and we evaluated their behavioral responses, investigating both emotional and cognitive competencies during adolescence. In addition, we assessed alterations in immune activation and brain plasticity by measuring the expression levels of several pro- and anti-inflammatory cytokines and neural plasticity markers. Finally, we investigated the hormonal stress response by evaluating the hypothalamic-pituitary-adrenal (HPA) axis reactivity. Our findings indicate that adolescent social isolation leads to the development of depressive- and anxiety-like traits, although it impacts distinct behavioral domains with varying degrees in males and females. Both genders exhibited deficiencies in the emotional realm, displaying enhanced anhedonia and anxiety compared to their respective control groups. Moreover, males exhibited cognitive impairments linked to an altered HPA axis activity. Remarkably, social isolation influenced immune activation in both sexes, resulting in decreased pro-inflammatory markers. Overall, these results affirm the significant impact of social experiences during adolescence on neurodevelopment. Notably, our study reveals that both males and females are equally susceptible to the effects of isolation, although sex-specific differences become apparent in the alterations observed at both behavioral and physiological levels.

Relationship between klotho, neurotrophic factors (BDNF, NGF, GDNF) and cognitive functions in patients with bipolar disorder

BACKGROUND

Klotho and neurotrophic factors, including brain-derived neurotrophic factor (BDNF), nerve growth factor (NGF), and glial cell line-derived neurotrophic factor (GDNF), have been shown to play a role in cognitive functions. However, these molecules have not been investigated in bipolar disorder simultaneously to assess the interactions among them and their relationships with cognitive functions. This study investigated the relationships among cognitive function, klotho, and neurotrophic factors in patients with bipolar disorder in the remission period.

METHODS

Male, bipolar disorder (BD) patients (patient group, n = 48) in the remission period and healthy volunteers (control group, n = 48) were included in the study. The Stroop test and Wechsler Memory Scale-Visual Production Subtest were applied, and the serum levels of Klotho, BDNF, GDNF, and NGF were measured with an ELISA reader.

RESULTS

The klotho protein levels (0.12 ± 0.15 and 0.17 ± 0.16) and NGF levels (34.36 ± 41.99 and 48.54 ± 41.06) in the patient group were significantly lower than those in the control group (Z = -3.071, p = 0.002 and Z = -2.217, p = 0.027, respectively). In the patient group, there was a positive correlation between the klotho and NGF levels (p = 0.003, rs = 0.413), and a negative correlation was detected between the NGF and GDNF levels (p = 0.013, rs = -0.355). Klotho and NGF were predictors of Weshler 40-min test results (adjusted R2 = 0.467), and Klotho and BDNF were predictors of Stroop test colour word reading time (adjusted R2 = 0.391) with other variables.

CONCLUSION

In BD patients, klotho, BDNF, GDNF and NGF are associated with cognitive functions and exhibit different characteristics from those of the control group. Nevertheless, the differences related to these molecules seem to be associated with a regulatory system rather than merely an increase or decrease in serum levels.

Brain function abnormalities and inflammation in HIV-positive men who have sex with men with depressive disorders

Background

Depressive disorders are highly prevalent among people with HIV (PWH) and are related to aberrant inflammation and immune responses. However, there is currently a lack of investigation into the neurological, inflammatory, endocrine, and immune aspects of HIV-associated depressive disorders (HADD).

Methods

The study involved 33 HIV-positive men who have sex with men with depressive disorders (HADD group) and 47 without neuropsychiatric disorders (HIV control group). Participants underwent resting-state functional magnetic resonance imaging (rs-fMRI) scans and assessments of peripheral blood. Peripheral blood cytokines, plasma concentrations of hormone and neurotrophic factors, and immune cell levels were determined using liquid chip, enzyme-linked immunosorbent assay, and flow cytometry, respectively. The correlation of imaging alterations with clinical variables and peripheral blood indicators was assessed.

Results

Compared to the HIV control group, the HADD group exhibited a higher fractional amplitude of low-frequency fluctuations in the left superior parietal gyrus, lower regional homogeneity in the left precentral gyrus, and reduced voxel-wise functional connectivity for the seed region in the right precentral gyrus with clusters in the right cuneus, etc. Furthermore, the HADD group had higher levels of interferon-gamma, a higher frequency of non-classical monocytes, and higher expression levels of perforin and CD38 on specific cells. These imaging results were significantly correlated with peripheral blood indicators and clinical variables.

Conclusion

This rs-fMRI study provides considerable evidence for abnormal intrinsic brain activity in people with HADD. Furthermore, our data also indicate the detrimental effects of depression-related inflammation on PWH. Therefore, it is imperative to increase attention to HADD and implement effective preventive interventions accordingly.

Endocrine Disrupting Toxicity of Bisphenol A and Its Analogs: Implications in the Neuro-Immune Milieu

Endocrine-disrupting chemicals (EDCs) are natural or synthetic substances that are able to interfere with hormonal systems and alter their physiological signaling. EDCs have been recognized as a public health issue due to their widespread use, environmental persistence and the potential levels of long-term exposure with implications in multiple pathological conditions. Their reported adverse effects pose critical concerns about their use, warranting their strict regulation. This is the case of bisphenol A (BPA), a well-known EDC whose tolerable daily intake (TDI) was re-evaluated in 2023 by the European Food Safety Authority (EFSA), and the immune system has been identified as the most sensitive to BPA exposure. Increasing scientific evidence indicates that EDCs can interfere with several hormone receptors, pathways and interacting proteins, resulting in a complex, cell context-dependent response that may differ among tissues. In this regard, the neuronal and immune systems are important targets of hormonal signaling and are now emerging as critical players in endocrine disruption. Here, we use BPA and its analogs as proof-of-concept EDCs to address their detrimental effects on the immune and nervous systems and to highlight complex interrelationships within the immune-neuroendocrine network (INEN). Finally, we propose that Receptor for Activated C Kinase 1 (RACK1), an important target for EDCs and a valuable screening tool, could serve as a central hub in our toxicology model to explain bisphenol-mediated adverse effects on the INEN.

Gelsemium low doses protect against serum deprivation-induced stress on mitochondria in neuronal cells

ETHNOPHARMACOLOGICAL RELEVANCE

Gelsemium dynamized dilutions (GDD) are known as a remedy for a wide range of behavioral and psychological symptoms of depression and anxiety at ultra-low doses, yet the underlying mechanisms of the mode of action of G. sempervirens itself are not well understood.

AIM OF THE STUDY

The present study was designed to examine the neuroprotective effects of Gelsemium preparations in counteracting stress-related mitochondrial dysfunctions in neuronal cells.

MATERIALS AND METHODS

We started by studying how serum deprivation affects the mitochondrial functions of human neuroblastoma (SH-SY5Y) cells. Next, we looked into the potential of various Gelsemium dilutions to improve cell survival and ATP levels. After identifying the most effective dilutions, 3C and 5C, we tested their ability to protect SH-SY5Y cells from stress-induced mitochondrial deficits. We measured total and mitochondrial superoxide anion radicals using fluorescent dyes dihydroethidium (DHE) and the red mitochondrial superoxide indicator (MitoSOX). Additionally, we assessed total nitric oxide levels with 4,5-diaminofluorescein diacetate (DAF-2DA), examined the redox state using pRA305 cells stably transfected with a plasmid encoding a redox-sensitive green fluorescent protein, and analyzed mitochondrial network morphology using an automated high-content analysis device, Cytation3. Furthermore, we investigated bioenergetics by measuring ATP production with a bioluminescence assay (ViaLighTM HT) and evaluated mitochondrial respiration (OCR) and glycolysis (ECAR) using the Seahorse Bioscience XF24 Analyzer. Finally, we determined cell survival using an MTT reduction assay.

RESULTS

Our research indicates that Gelsemium dilutions (3C and 5C) exhibited neuroprotective effects by: - Normalizing total and mitochondrial superoxide anion radicals and total nitric oxide levels. - Regulating the mitochondrial redox environment and mitochondrial networks morphology. - Increasing ATP generation as well as OCR and ECAR levels, thereby reducing the viability loss induced by serum withdrawal stress.

CONCLUSIONS

These findings highlight that dynamized Gelsemium preparations may have neuroprotective effects against stress-induced cellular changes in the brain by regulating mitochondrial functions, essential for the survival, plasticity, and function of neurons in depression.

Neuroplasticity-related effects of vitamin D relevant to its neuroprotective effects: A narrative review

The pathophysiology of a wide range of central nervous system (CNS) disorders, such as neurodegenerative and psychiatric diseases, has been associated with impairment of neurogenic and synaptogenic processes. Therefore, pharmacological and/or nutritional strategies based on the stimulation and/or restoration of these processes may have beneficial effects against diseases in which these processes are impaired. In this context, vitamin D has emerged as a promising neuroprotective compound. Due to its pleiotropic properties, it can interact with multiple molecular targets and thereby affect different cell types, including neurons and glial cells. This neurosteroid contributes to CNS homeostasis by non-genomic and genomic mechanisms through its interaction with vitamin D receptors (VDRs). Among several properties of this vitamin, its role in neuronal proliferation and differentiation as well as in synaptic plasticity has received attention. Considering this background, this narrative review aims to highlight the neuroplasticity-related mechanisms of vitamin D that may be associated with its neuroprotective effects.

Neuroplasticity and Mechanisms of Action of Acute and Chronic Treatment with Antidepressants in Preclinical Studies

Pharmacotherapy for depression includes drugs such as monoamine oxidase inhibitors (MAOIs), tricyclic antidepressants (TCAs), selective serotonin reuptake inhibitors (SSRIs), noradrenaline (NA) and serotonin (5-HT) reuptake inhibitors (NaSSAs), and atypical antidepressants; these drugs exert differentially beneficial effects on symptoms of depression after acute and chronic treatment in animal models. Said effects are established through neuroplastic mechanisms involving changes in neurogenesis and synaptogenesis as result of the activation of intracellular signaling pathways associated with neurochemical and behavioral changes. Antidepressants increase the synaptic availability of monoamines (monoaminergic hypothesis) such as 5-HT, NA, and gamma-aminobutyric acid (GABA) by inhibiting their reuptake or degradation and activating intracellular signaling pathways such as the responsive element binding protein (cAMP-CREB) cascade, which regulates the expression of genes related to neuroplasticity and neurogenesis, such as brain-derived neurotrophic factor (BDNF), in various brain structures implicated in depression. The aim of this review is to analyze the mechanisms of action of different antidepressants and to compare the effects of acute and chronic treatment on neuroplasticity in animal models of depression. A thorough search was conducted in PubMed, Scopus, and Web of Science, focusing on studies since 1996 with keywords like antidepressants, acute and chronic treatment, neuroplasticity, and experimental depression. Studies included had to investigate antidepressant effects experimentally, with full-text access, while excluding those that did not. Data extraction focused on study design, findings, and relevance to understanding treatment differences. Only high-quality, peer-reviewed studies were considered to ensure a comprehensive synthesis of current knowledge.

Environmental Affordance for Physical Activity, Neurosustainability, and Brain Health: Quantifying the Built Environment's Ability to Sustain BDNF Release by Reaching Metabolic Equivalents (METs)

Background/Objectives: Unlike enriched environments for rodents, human-built environments often hinder neuroplasticity through sedentary lifestyles, to which exercise can merely overcome its adverse effects. This paper introduces "environmental affordance for physical activity" to quantify the potential of spatial layout designs to stimulate activity and sustain neuroplasticity, mainly hippocampal neurogenesis. Methods: A novel framework links metabolic equivalents (METs) that can be afforded by the spatial layout of the built environment to its role in increasing the brain-derived neurotrophic factor (BDNF)-a biomarker that promotes and sustains adult hippocampal neurogenesis and synaptic plasticity. Equations are developed to assess the built environment's affordance for physical activity through BDNF changes measurable after brief exposure to the built environment for 20-35 min. Results: The developed equations are evidenced to be feasible to cause BDNF release through low- to moderate-intensity physical activity. This model provides a feasible assessment tool to test the built environment's effectiveness towards neurosustainability. Conclusions: By sustaining neurogenesis, the environmental affordance for physical activity holds promise for improving mental health and preventing cognitive decline.

Deciphering the role of miRNA-134 in the pathophysiology of depression: A comprehensive review

This study summarizes the significance of microRNA-134 (miRNA-134) in the pathophysiology, diagnosis, and treatment of depression, a disease still under investigation due to its complexity. miRNA-134 is an endogenous short non-coding RNA that can bind to the 3' untranslated region (3'UTR) of miRNA-134, inhibiting gene translation and showing great potential in the regulation of mood, synaptic plasticity, and neuronal function. This study included 15 articles retrieved from four English-language databases: PubMed, Embase, The Cochrane Library, and Web of Science, and three Chinese literature databases: CNKI, Wanfang, and Chinese Science and Technology Periodical Database (VIP).We evaluated each of the 15 articles using the Critical Appraisal Skills Program (CASP) tool.The standard integrates analyzes of genomic, transcriptomic, neuroimaging, and behavioral data analyses related to miRNA-134 and depression. A multidimensional framework based on standardized criteria was used for quality assessment. The main findings indicate that miRNA-134 significantly affects synaptic plasticity and neurotransmitter regulation, in particular the synthesis and release of serotonin and dopamine. miRNA-134 shows high sensitivity and specificity as a biomarker for the diagnosis of depression and has therapeutic potential for the targeted treatment of depression. miRNA-134 plays a crucial role in the pathogenesis of depression, providing valuable insights for early diagnosis and the development of targeted therapeutic strategies. This work highlights the potential of miRNA-134 as a focal point for advancing personalized medicine approaches for depression.

Efficacy and safety of add-on sarcosine in patients with major depressive disorder: A randomized controlled trial

The main hurdles with current therapies for major depressive disorder (MDD) include lack of efficacy, therapeutic latency, and adverse drug reactions. Add-on therapy to conventional antidepressants may result in better therapeutic outcomes to overcome these obstacles. Sarcosine (N-methyl glycine), an endogenous amino acid that acts by modulating the NMDA receptor, is available as a dietary supplement. So, the present study was planned to evaluate the efficacy and safety of add-on sarcosine to SSRIs in MDD. In the present randomized, double-blind clinical trial (NCT04975100), 60 eligible participants with MDD were randomly assigned to either the test group (SSRI + sarcosine) or the control group (SSRI + placebo). Clinical and biochemical parameters like MADRS, CGI, serum BDNF, and serum glycine were assessed at baseline and eight weeks. The mean reduction in MADRS score was significant in both the control (-8.7, 95% CI: -11.0 to -6.4, p < 0.001) and the test group (-13.3, 95% CI: -14.9 to -11.7, p < 0.001), but the change in the test group was significantly greater (-4.6, 95% CI: -7.5 to -1.7, p = 0.003). The test group had a significantly higher response rate (p = 0.007) and remission rate (p = 0.038) compared to the control group. There was a significant increase in serum BDNF in both groups; however, the change in the test group was significantly higher than in the control group (p = 0.041). Similarly, the test group had a significantly higher increase in serum glycine than the control group (p < 0.001). Sarcosine may be considered an efficacious and safe add-on therapy to standard SSRIs in the management of MDD. ClinicalTrial.gov IdentifierNCT04975100.

Pathogenesis and therapeutic strategies for cancer-related depression

Depression is a common co-morbidity among cancer cases, which has a detrimental influence on cancer treatment and prognosis. Recent advancements in the neurobiology of depression and cancer pathophysiology have revealed several shared biobehavioral mechanisms and introduced new therapeutic strategies. In this review, we summarize the biological mechanisms driving cancer-related depression, including psychosocial factors, immuno-inflammatory processes, chronic stress, dysbiosis of gut microbiota, and medically-induced factors. Interventions used for cancer-related depression may include psychosocial therapies, pharmacological therapies, immunotherapies, psychobiological medications, and dietary strategies. This review could inspire the elucidation of possible co-occurring mechanisms and complex interactions between cancer and depression, provide an opportunity to propose faster and more effective therapies for cancer-related depression, and well as new strategies for cancer in the future.

Can electroencephalography (EEG) identify the different dimensions of pain in fibromyalgia? A pilot study

BACKGROUND

Electroencephalography (EEG) is a promising tool for identifying the physiological biomarkers of fibromyalgia (FM). Evidence suggests differences in power band and density between individuals with FM and healthy controls. EEG changes appear to be associated with pain intensity; however, their relationship with the quality of pain has not been examined. We aimed to investigate whether abnormal EEG in the frontal and central points of the 10-20 EEG system in individuals with FM is associated with pain's sensory-discriminative and affective-motivational dimensions. The association between EEG and the two dimensions of emotional disorders (depression and anxiety) was also investigated.

METHODS

In this cross-sectional pilot study, pain experience (pain rating index [PRI]) and two dimensions of emotional disorders (depression and anxiety) were assessed using the McGill Pain Questionnaire (PRI-sensory and PRI-affective) and Hospital Anxiety and Depression Scale (HADS), respectively. In quantitative EEG analysis, the relative spectral power of each frequency band (delta, theta, alpha, and beta) was identified in the frontal and central points during rest.

RESULTS

A negative correlation was found between the relative spectral power for the delta bands in the frontal (r= -0.656; p = 0.028) and central points (r= -0.624; p = 0.040) and the PRI-affective scores. A positive correlation was found between the alpha bands in the frontal (r = 0.642; p = 0.033) and central points (r = 0.642; p = 0.033) and the PRI-affective scores. A negative correlation between the delta bands in the central points and the anxiety subscale of the HADS (r = -0.648; p = 0.031) was detected.

CONCLUSION

The affective-motivational dimension of pain and mood disorders may be related to abnormal patterns of electrical activity in patients with FM.

TRIAL REGISTRATION

Retrospectively registered on ClinicalTrials.gov (NCT05962658).

Investigating Neuroplasticity Changes Reflected by BDNF Levels in Astrocyte-Derived Extracellular Vesicles in Patients with Depression

Purpose

To investigate the neuroplasticity hypothesis of depression by measuring brain-derived neurotrophic factor (BDNF) levels in plasma astrocyte-derived extracellular vesicles (ADEVs) and to evaluate their potential as biomarkers for depression compared with plasma BDNF levels.

Patients and Methods

Thirty-five patients with major depressive disorder (MDD) and 35 matched healthy controls (HCs) were enrolled. Plasma ADEVs were isolated using a combination of ultracentrifugation and immunoaffinity capture. Isolated ADEVs were validated using transmission electron microscopy, nanoparticle tracking analysis, and Western blotting. BDNF levels were quantified in both ADEVs and plasma. ALG-2-interacting protein X (Alix) and cluster of differentiation 81 (CD81) levels, two established extracellular vesicle markers, were measured in ADEVs.

Results

After false discovery rate correction, patients with MDD exhibited higher CD81 levels (P FDR = 0.040) and lower BDNF levels (P FDR = 0.043) in ADEVs than HCs at baseline. BDNF levels in ADEVs normalized to CD81 (P FDR = 0.002) and Alix (P FDR = 0.040) remained consistent with this finding. Following four weeks of selective serotonin reuptake inhibitor treatment (n=10), CD81 levels in ADEVs decreased (P FDR = 0.046), while BDNF levels normalized to CD81 increased (P FDR = 0.022). BDNF levels in ADEVs were more stable than in plasma. Exploratory analysis revealed no correlation between BDNF levels in ADEVs and plasma (ρ=0.117, P = 0.334).

Conclusion

This study provides human in vivo evidence supporting the neuroplasticity hypothesis of depression by demonstrating altered BDNF levels in ADEVs. ADEVs may be more suitable for developing biomarkers of depression than plasma-derived biomarkers.

Tremendous Fidelity of Vitamin D3 in Age-related Neurological Disorders

Vitamin D3 (VD) is a secosteroid hormone and shows a pleiotropic effect in brain-related disorders where it regulates redox imbalance, inflammation, apoptosis, energy production, and growth factor synthesis. Vitamin D3's active metabolic form, 1,25-dihydroxy Vitamin D3 (1,25(OH)2D3 or calcitriol), is a known regulator of several genes involved in neuroplasticity, neuroprotection, neurotropism, and neuroinflammation. Multiple studies suggest that VD deficiency can be proposed as a risk factor for the development of several age-related neurological disorders. The evidence for low serum levels of 25-hydroxy Vitamin D3 (25(OH)D3 or calcidiol), the major circulating form of VD, is associated with an increased risk of Alzheimer's disease (AD), Parkinson's disease (PD), Huntington's disease (HD), dementia, and cognitive impairment. Despite decades of evidence on low VD association with neurological disorders, the precise molecular mechanism behind its beneficial effect remains controversial. Here, we will be delving into the neurobiological importance of VD and discuss its benefits in different neuropsychiatric disorders. The focus will be on AD, PD, and HD as they share some common clinical, pathological, and epidemiological features. The central focus will be on the different attributes of VD in the aspect of its anti-oxidative, anti-inflammatory, anti-apoptotic, anti-cholinesterase activity, and psychotropic effect in different neurodegenerative diseases.

Deciphering Depression: Epigenetic Mechanisms and Treatment Strategies

Depression, a significant mental health disorder, is under intense research scrutiny to uncover its molecular foundations. Epigenetics, which focuses on controlling gene expression without altering DNA sequences, offers promising avenues for innovative treatment. This review explores the pivotal role of epigenetics in depression, emphasizing two key aspects: (I) identifying epigenetic targets for new antidepressants and (II) using personalized medicine based on distinct epigenetic profiles, highlighting potential epigenetic focal points such as DNA methylation, histone structure alterations, and non-coding RNA molecules such as miRNAs. Variations in DNA methylation in individuals with depression provide opportunities to target genes that are associated with neuroplasticity and synaptic activity. Aberrant histone acetylation may indicate that antidepressant strategies involve enzyme modifications. Modulating miRNA levels can reshape depression-linked gene expression. The second section discusses personalized medicine based on epigenetic profiles. Analyzing these patterns could identify biomarkers associated with treatment response and susceptibility to depression, facilitating tailored treatments and proactive mental health care. Addressing ethical concerns regarding epigenetic information, such as privacy and stigmatization, is crucial in understanding the biological basis of depression. Therefore, researchers must consider these issues when examining the role of epigenetics in mental health disorders. The importance of epigenetics in depression is a critical aspect of modern medical research. These findings hold great potential for novel antidepressant medications and personalized treatments, which would significantly improve patient outcomes, and transform psychiatry. As research progresses, it is expected to uncover more complex aspects of epigenetic processes associated with depression, enhance our comprehension, and increase the effectiveness of therapies.

Selective knockdown of GABAA-α2 subunit in the dorsal dentate gyrus in adulthood induces anxiety, learning and memory deficits and impairs synaptic plasticity

Animal studies and clinical trials suggest that maintenance of gamma-aminobutyric acid (GABA)-ergic activity may be crucial in coping with stressful conditions, anxiety and mood disorders. Drugs highly efficient in promoting anxiolysis were shown to activate this system, particularly via the α2-subunit of type A receptors (GABAA α2). Given the high expression of GABAA α2 in the dentate gyrus (DG) sub-field of the hippocampus, we sought to examine whether manipulation of the α2 subunit in this area will evoke changes in emotional behaviour, memory and learning as well as in synaptic plasticity. We found that knockdown of GABAAα2 receptor specifically in the dorsal DG of rats caused increased anxiety without affecting locomotor activity. Spatial memory and learning in the Morris water maze were also impaired in GABAAα2 receptor knocked down rats, an effect accompanied by alterations in synaptic plasticity, as assessed by long-term potentiation in the DG. Our findings provide further support to the notion that emotional information processing in the hippocampus may be controlled, at least in part, via the inhibitory GABAA α2 receptor subunit, opening a potential avenue for early interventions from pre- puberty into adulthood, as a strategy for controlling anxiety-related psychopathology.

Luteolin promotes neuronogenesis in hippocampus of chronic unpredictable mild stress rats and primary hippocampus of fetal rats

OBJECTIVE

To investigate the effects of luteolin on chronic unpredictable mild stress (CUMS)-induced depressive rats and corticosterone (CORT)-induced depressive primary hippocampal neurons, and to elucidate the mechanism behind the action.

METHODS

The antidepressant mechanism of luteolin was studied by using CUMS rat model and primary hippocampal neurons in fetal rats. In vivo, novelty suppressed feeding, open-field and sucrose preference tests as well as Morris water maze were evaluated. The content of brain derived neurotrophic factor (BDNF), 5-hydroxytryptamine (5-HT), norepinephrine (NE), and dopamine (DA) in serum were detected by enzyme-linked immunosorbent assay. The mechanisms of luteolin were explored based on neurotrophin and hippocampal neurogenesis, and proliferation. Survival of the septo-temporal axis in hippocampus was assayed using the 5-bromo-2-deoxyuridine (BrdU), the expression of BDNF, neurotrophin-3 (NT-3), and nerve growth factor (NGF) in hippocampus dentate gyrus region were measured by Western-blotting. In vitro, BDNF, NT-3, tropomyosin receptor kinase B (TrkB), and phosphorylated cyclic adenosine monophosphate responsive element binding protein (p-CREB) were detected through the high content analysis (HCA) to investigate neurotrophin and apoptosis.

RESULTS

Induction of CUMS in rats induced depressive symptoms, while luteolin significantly enhanced sucrose consumption, decreased feeding latency, increased locomotor activity, escape latency, distance of target quadrant and regulated the content of depressive-like biomarkers. Histology analysis revealed that luteolin increased the abundance of new born neurons that had been labeled with BrdU, BrdU + neuronal nuclear antigen, and BrdU + doublecortin in septo-temporal axis of S2 (mid-septal) and T3 (mid-temporal). Moreover, expression of BDNF, NT-3, and NGF increased significantly in the septo-temporal axis of S2 and T3. HCA showed increased expression of BDNF, NT-3, TrkB and p-CREB in primary hippocampal neurons.

CONCLUSION

The results provided direct evidence that luteolin has an antidepressant effect and could effectively promote the regeneration of the septotemporal axis nerve and hippocampal neuronutrition, which suggested that the antidepressant effect of luteolin may be related to hippocampal neurogenesis.

Levels of brain-derived neurotrophic factor (BDNF) among patients with COVID-19: a systematic review and meta-analysis

Many individuals have been suffering from consistent neurological and neuropsychiatric manifestations even after the remission of coronavirus disease (COVID-19). Brain-derived neurotrophic factor (BDNF) is a protein involved in the regulation of several processes, including neuroplasticity, neurogenesis, and neuronal differentiation, and has been linked to a range of neurological and psychiatric disorders. In this study, we aimed to synthesize the available evidence on the profile of BDNF in COVID-19. A comprehensive search was done in the Web of Science core collection, Scopus, and MEDLINE (PubMed), and Embase to identify relevant studies reporting the level of BDNF in patients with COVID-19 or those suffering from long COVID. We used the NEWCASTLE-OTTAWA tool for quality assessment. We pooled the effect sizes of individual studies using the random effect model for our meta-analysis. Fifteen articles were included in the systematic review. The sample sizes ranged from 16 to 183 participants. Six studies compared the level of BDNF in COVID-19 patients with healthy controls. The pooled estimate of the standardized mean difference in BDNF level between patients with COVID-19 and healthy individuals was - 0.84 (95% CI - 1.49 to - 0.18, p = 0.01, I2 = 81%) indicating a significantly lower BDNF level in patients with COVID-19. Seven studies assessed BDNF in different severity statuses of patients with COVID-19. The pooled estimate of the standardized mean difference in BDNF level was - 0.53 (95% CI - 0.85 to - 0.21, p = 0.001, I2 = 46%), indicating a significantly lower BDNF level in patients with more severe COVID-19. Three studies evaluated BDNF levels in COVID-19 patients through different follow-up periods. Only one study assessed the BDNF levels in long COVID patients. Sensitivity analyses did not alter the significance of the association. In this study, we showed a significant dysregulation of BDNF following COVID-19 infection. These findings may support the pathogenesis behind the long-lasting effects of this disease among infected patients. PROSPERO: CRD42023413536.

Effects of antidepressant and antipsychotic medication on peripheral brain-derived neurotrophic factor concentration: Systematic review and meta-analysis

Brain-derived neurotrophic factor (BDNF) is an important regulatory protein in the pathophysiology of psychiatric disorders. Several studies have reported the relationship between peripheral BDNF concentrations and the use of psychoactive drugs. However, the results remain controversial. This study aimed to evaluate the effects of psychoactive drugs on BDNF concentrations and to explore the association between changes in BDNF concentrations and improvements in clinical scores. A systematic review and meta-analysis were conducted. Six electronic databases, including PubMed, Scopus, Medline, Web of Science, Google Scholar and Science Direct, were searched. Changes in BDNF concentrations were compared before and after psychoactive treatment, using the standardized mean difference (SMD) and 95 % confidence interval (95 % CI). Twenty-three studies were included. A significant increase in serum BDNF concentrations was observed after treatment with antipsychotics (SMD=0.43; 95 %CI: 0.26, 0.60) and antidepressants (SMD=0.49; 95 %CI: 0.23, 0.74). However, the plasma BDNF concentration was not affected by antidepressant and antipsychotic medication. Although an improvement in clinical scores was observed after treatment, no significant association was observed between changes in BDNF concentrations and the changes in the Positive and Negative Syndrome Scale (PANSS) and the Hamilton Depression Rating Scale (HAM-D) scores. In conclusion, antidepressants and antipsychotics increase serum BDNF concentrations.

Psilocybin promotes neuroplasticity and induces rapid and sustained antidepressant-like effects in mice

BACKGROUND

Psilocybin offers new hope for treating mood disorders due to its rapid and sustained antidepressant effects, as standard medications require weeks or months to exert their effects. However, the mechanisms underlying this action of psilocybin have not been identified.

AIMS

To investigate whether psilocybin has rapid and sustained antidepressant-like effects in mice and investigate whether its potential mechanisms of action are related to promoted neuroplasticity.

METHODS

We first examined the antidepressant-like effects of psilocybin in normal mice by the forced swimming test and in chronic corticosterone (CORT)-exposed mice by the sucrose preference test and novelty-suppressed feeding test. Furthermore, to explore the role of neuroplasticity in mediating the antidepressant-like effects of psilocybin, we measured structural neuroplasticity and neuroplasticity-associated protein levels in the prefrontal cortex (PFC) and hippocampus.

RESULTS

We observed that a single dose of psilocybin had rapid and sustained antidepressant-like effects in both healthy mice and chronic CORT-exposed mice. Moreover, psilocybin ameliorated chronic CORT exposure-induced inhibition of neuroplasticity in the PFC and hippocampus, including by increasing neuroplasticity (total number of dendritic branches and dendritic spine density), synaptic protein (p-GluA1, PSD95 and synapsin-1) levels, BDNF-mTOR signalling pathway activation (BDNF, TrkB and mTOR levels), and promoting neurogenesis (number of DCX-positive cells).

CONCLUSIONS

Our results demonstrate that psilocybin elicits robust, rapid and sustained antidepressant-like effects which is accompanied by the promotion of neuroplasticity in the PFC and hippocampus.

A potential research target for cardiac rehabilitation: brain-derived neurotrophic factor

Cardiovascular diseases pose a major threat to human life, functional activity, and quality of life. Once the disease is present, patients can experience varying degrees of problems or limitations on three levels: physical, psychological, and social. Patients with cardiovascular disease are always at risk for adverse cardiac events, decreased physical activity, psychoemotional disturbances, and limited social participation due to their varying pathologies. Therefore, personalized cardiac rehabilitation is of great significance in improving patients' physical and mental functions, controlling disease progression, and preventing deterioration. There is a consensus on the benefits of cardiac rehabilitation in improving patients' quality of life, enhancing functional activity, and reducing mortality. As an important part of cardiac rehabilitation, Exercise plays an irreplaceable role. Aerobic exercise, resistance training, flexibility training, and other forms of exercise are recommended by many experts. Improvements in exercise tolerance, lipid metabolism, cardiac function, and psychological aspects of the patients were evident with appropriate exercise interventions based on a comprehensive assessment. Further studies have found that brain-derived neurotrophic factor may be an important mediator of exercise's ability to improve cardiovascular health. Brain-derived neurotrophic factor exerts multiple biological effects on the cardiovascular system. This article provides another perspective on the cardiac effects of exercise and further looks at the prospects for the use of brain-derived neurotrophic factor in cardiac rehabilitation. Meanwhile, the new idea that brain-derived neurotrophic factor is a key mediator connecting the brain-cardiac axis is proposed in light of the current research progress, to provide new ideas for clinical rehabilitation and scientific research.

Treatment of Depression with Acupuncture Based on Pathophysiological Mechanism

Depression is a prevalent mental disorder and has a profound impact on an individual's psychological and physical well-being. It is characterized by a persistently depressed mood, loss of interest, energy loss, and cognitive dysfunction. In recent years, more and more people have changed to mental diseases, such as depression, anxiety, mania and so on. In the incidence of depression, covering all ages, but still mainly young and middle-aged women. Traditional treatments for depression mainly rely on medication and psychotherapy, but these methods are not effective for all patients and are often accompanied by certain side effects. Therefore, finding safe and effective alternative or adjuvant treatments has become a priority. Here we highlight the research progress of acupuncture in the treatment of depression and to explore the mechanism of acupuncture in the treatment of depression. Acupuncture treatment of depression is an ancient and effective method, the mechanism involves multiple biological pathways, for example, by regulating neurotransmitter levels, regulating the neuroendocrine axis, improving neuroplasticity, anti-inflammatory and other effects, improving emotional state and play an antidepressant role. To provide evidence to support the widespread use of acupuncture in clinical practice. We hope to provide new treatment ideas and methods for patients with depression, and even reduce the incidence of depression.

Research on the mechanism of antidepressive effect of Suanzaoren Decoction through TLR4/MyD88/NF-κB pathway and Wnt/β-catenin pathway

ETHNOPHARMACOLOGICAL RELEVANCE

Increased inflammatory response and disruption of neuroplasticity are important mechanisms in the hypothesis of the pathogenesis of depression. Thus, these two aspects are conducive to the development of treatments for depression. Suanzaoren Decoction (SZRD) is a classic traditional Chinese medicine compound for the treatment of insomnia, which can clinically relieve depression symptoms, but its antidepressant pharmacological mechanism remains to be elucidated.

AIM OF THIS STUDY

Based on the hypothesis of inflammation and neuroplasticity in depression, this study aimed to investigate the antidepressant effect of SZRD and its specific molecular mechanism through chronic unpredictable mild stress (CUMS) induced SD rat model and lipopolysaccharide (LPS) induced BV2 cell neuroinflammation model.

MATERIALS AND METHODS

The body weight and behavioral indexes of CUMS model rats treated with orally or without oral SZRD for 4 weeks were detected. Hematoxylin and eosin staining was used to observe brain pathological damage. Terminal-deoxynucleoitidyl Transferase Mediated Nick End Labeling (TUNEL) staining was used to observe neuronal apoptosis. Immunofluorescence, ELISA kit and Western blotting were used to detect the inflammatory index Iba-1 and inflammatory factors, as well as the important inflammatory pathway TLR4/MyD88/NF-κB. Enzyme linked immunosorbent assay (ELISA) and western blotting were used to detect neuroplasticity indexes proteins-brain-derived neurotrophic factor (BDNF), presynaptic membrane protein-synaptophysin (SYP), and postsynaptic protein- 95(PSD95), and the key pathway Wnt/β-catenin. The possible mechanism of SZRD antidepressant was further explored in LPS-induced BV2 cells.

RESULTS

In vivo and in vitro experiments showed that SZRD treatment significantly reversed the depression-like behaviors in rats, decreased the levels of inflammatory factors and increased the expression levels of BDNF, SYP, PSD95 in depression model rats. Furthermore, SZRD treatment inhibited the activation of TLR4/MyD88/NF-κB and Wnt/β-catenin pathways and reduced the massive nuclear translocation of NF-κB and β-catenin. The addition of NF-κB pathway agonists could partially offset the inhibitory effect of SZRD on the Wnt pathway, and the addition of Wnt pathway agonists could also partially offset the inhibitory effect of SZRD on the TLR4 pathway.

CONCLUSION

This study suggestted that SZRD may exert its antidepressant effect by regulating TLR4/MyD88/NF-κB pathway and Wnt/β-catenin pathway in combination.

Effect of Transcranial Direct Current Stimulation (tDCS) on Depression in Parkinson's Disease-A Narrative Review

INTRODUCTION

Depression is the most prevalent comorbid neuropsychiatric condition in individuals with Parkinson's disease (PD), and its underlying mechanisms are not yet fully understood. Current treatment methods are characterised by moderate effectiveness and possible side effects, prompting the search for new non-invasive and safe treatment methods.

METHODS

This narrative review explores the use of transcranial direct current stimulation (tDCS) in the treatment of depression in PD, based on neuropsychological measures. Searches were conducted in the PubMed/Medline, Research Gate, and Cochrane databases.

RESULTS

Nine relevant studies were identified, where depression scores served as either primary or secondary outcomes. Stimulation protocols displayed heterogeneity, especially concerning choice of stimulation site. Patient samples were also heterogeneous. The majority of the studies incorporated anodal stimulation targeting the left dorsolateral prefrontal cortex (DLPFC). The results revealed a reduction in depression scores among PD patients following tDCS. Potential mechanisms through which tDCS may alleviate depression in PD were discussed and recommendations for future research were made.

CONCLUSIONS

Preliminary evidence suggests that tDCS applied anodally to the left DLPFC reduces depression scores in people with PD; however, due to the heterogeneity of the studies analysed, the use of tDCS in this field should be approached with caution and warrants further validation and confirmation.

Serum levels of interleukin-33 and mesencephalic astrocyte derived neurotrophic factors in patients with major depressive disorder: a cross-sectional comparative design

BACKGROUND

Major depressive disorder (MDD) is a debilitating health condition that has significant morbidity and mortality rates. Depression can be caused due to social, biological, environmental, psychological, and genetic factors. A few biological processes have been proposed as the pathophysiological pathways of depression. Neurotrophic factors and inflammatory cytokines have been linked to depression. Thus, we aimed to investigate the serum interleukin-33 (IL-33) and mesencephalic astrocyte-derived neurotrophic factor (MANF) in MDD patients and corresponding healthy controls (HCs).

METHOD

This study involved the inclusion of 129 MDD patients and 125 HCs matched by sex and age. A psychiatrist evaluated the study participants following DSM-5 criteria. The severity of the illness was assessed utilizing the Hamilton Depression Rating Scale (Ham-D). The serum concentrations of IL-33 and MANF were measured using enzyme-linked immunosorbent assay (ELISA) kits.

RESULTS

The mean serum levels of IL-33 were decreased (159.12 ± 6.07 pg/ml vs. 180.60 ± 8.64 pg/ml, p = 0.042), and the MANF levels were increased (5.40 ± 0.19 ng/ml vs. 4.46 ± 0.21 ng/ml, p = 0.001) in MDD patients when compared to HCs.

CONCLUSIONS

The current study proposes that lower IL-33 and higher MANF serum levels are associated with MDD progression and depression severity. These biomarkers could be used as risk assessment tools for MDD. We recommend more investigation, including a significant population, to determine the precise function of IL-33 and MANF in depression.

Neuroplasticity: Pathophysiology and Role in Major Depressive Disorder

Neuroplasticity is characterized by the brain's ability to change its activity in response to extrinsic and intrinsic factors and is thought to be the mechanism behind all brain functions. Neuroplasticity causes structural and functional changes on a molecular level, specifically the growth of different regions in the brain and changes in synaptic and post-synaptic activities. The four types of neuroplasticity are homologous area adaption, compensatory masquerade, cross-modal reassignment, and map expansion. All of these help the brain work around injuries or new information inputs. In addition to baseline physical functions, neuroplasticity is thought to be the basis of emotional and mental regulations and the impairment of it can cause various mental illnesses. Concurrently, these mental illnesses further the damage of synaptic plasticity in the brain. Major depressive disorder (MDD) is one of the most common mental illnesses. It is affected by and accelerates the impairment of neuroplasticity. It is characterized by a chronically depressed state of mind that can impact the patient's daily life, including work life and interests. This review will focus on highlighting the physiological aspects of the disease and the role of neuroplasticity in the pathogenesis and pathology of the disorder. Moreover, the role of monoamine regulation and ketamine uptake will be discussed in terms of their antidepressant effects on the outcomes of MDD.

Altered in vivo early neurogenesis traits in patients with depression: Evidence from neuron-derived extracellular vesicles and electroconvulsive therapy

BACKGROUND

The neurogenesis hypothesis is a promising candidate etiologic hypothesis for depression, and it is associated with electroconvulsive therapy (ECT). However, human in vivo molecular-level evidence is lacking.

OBJECTIVE

We used neuron-derived extracellular vesicles (NDEVs) as a "window to the neurons" to explore the in vivo neurogenesis status associated with ECT in patients with treatment-resistant depression (TRD).

METHODS

In this study, we enrolled 40 patients with TRD and 35 healthy controls (HCs). We isolated NDEVs from the plasma of each participant to test the levels of doublecortin (DCX), a marker of neurogenesis, and cluster of differentiation (CD) 81, a marker of EVs. We also assessed the plasma levels of brain-derived neurotrophic factor (BDNF), a protein that is known to be associated with ECT and neuroplastic processes.

RESULTS

Our findings indicated that both the levels of DCX in NDEVs and BDNF in plasma were significantly lower in TRD patients compared to HCs at baseline, but increased following ECTs. Conversely, levels of CD81 in NDEVs were found higher in TRD patients at baseline, but did not change after the ECT treatments. Exploratory analyses revealed that lower levels of BDNF in plasma and DCX in NDEVs, along with higher CD81 levels in NDEVs, were associated with more severe depressive symptoms and reduced cognitive function at baseline. Furthermore, higher baseline CD81 concentrations in NDEVs were correlated with greater decreases in depression symptoms.

CONCLUSIONS

We first present human in vivo evidence of early neurogenesis using DCX through NDEVs: decreased in TRD patients, increased after ECTs.

Potential molecular pathways of angiotensin receptor blockers in the brain toward cognitive improvement in dementia

The alarming rise of cognitive impairment and memory decline and limited effective solutions present a worldwide concern for dementia patients. The multivariant role of the renin-angiotensin system (RAS) in the brain offers strong evidence of a role for angiotensin receptor blockers (ARBs) in the management of memory impairment by modifying glutamate excitotoxicity, downregulating inflammatory cytokines such as interleukin (IL)-1β, IL-6 and tumor necrosis factor (TNF)α, inhibiting kynurenine aminotransferase (KAT)-II, nucleotide-binding domain, leucine-rich-containing family and pyrin-domain-containing-3 (NLRP3) inflammasomes, boosting cholinergic activity, activating peroxisome proliferator-activated receptor (PPAR)-γ, countering cyclooxygenase (COX) and mitigating the hypoxic condition. The present work focuses on the intricate molecular mechanisms involved in brain-RAS, highlighting the role of ARBs, connecting links between evidence-based unexplored pathways and investigating probable biomarkers involved in dementia through supported preclinical and clinical literature.

Current genetic data on depression and anxiety in Parkinson's disease patients

Parkinson's disease (PD) is a common neurodegenerative disorder affecting about 1 % of the population over the age of 60 years. PD is characterized by a wide spectrum of symptomatology including not only motor symptoms but non-motor symptoms, as well. Depression is one of the most common non-motor manifestations, and the most frequent neuropsychiatric comorbidity in PD. Neuropsychiatric symptoms like depression and anxiety may precede the appearance of motor features, highlighting their importance in the early detection of the disease and its strategic management. This review discusses the possible genetic background of the development of these neuropsychiatric symptoms in PD patients analyzing current genetic data associated with this clinical entity.

Pharmacological Mechanism of Herbal Interventions for Bipolar Disorder

Bipolar disorder is a neuropsychiatric disease characterized by an abundance of undesired ideas and thoughts associated with recurrent episodes of mania or hypomania and depression. Alterations in the circuits, including the prefrontal cortex, striatum, and limbic system, regulate mood and cause variation in several crucial neurotransmitters, including serotonin, dopamine, GABA, and glutamate. Imbalances in dopamine levels have been implicated in the manic phase, while variance in serotonin is linked to depressive episodes. The precise pathophysiology of bipolar disorder is still unknown. Though different treatments are available, like lithium, risperidone, valproic acid, etc., which are widely used, they come with certain limitations, including narrow therapeutic index, hypothyroidism, weight gain, extrapyramidal symptoms, etc. The interest in herbal- based treatments for bipolar disorder arises from the desire for alternative, potentially more natural, and holistic approaches with fewer side effects. The current review focuses on the potential effects of herbal drugs and their derivatives to alleviate the symptoms of bipolar disorder.

Neuropsychological Effects of Antidepressants: Translational Studies

Pharmacological treatments that improve mood were first identified serendipitously, but more than half a century later, how these drugs induce their antidepressant effects remains largely unknown. With the help of animal models, a detailed understanding of their pharmacological targets and acute and chronic effects on brain chemistry and neuronal function has been achieved, but it remains to be elucidated how these effects translate to clinical efficacy. Whilst the field has been dominated by the monoamine and neurotrophic hypotheses, the idea that the maladaptive cognitive process plays a critical role in the development and perpetuation of mood disorders has been discussed since the 1950s. Recently, studies using objective methods to quantify changes in emotional processing found acute effects with conventional antidepressants in both healthy volunteers and patients. These positive effects on emotional processing and cognition occur without a change in the subjective ratings of mood. Building from these studies, behavioural methods for animals that quantify similar cognitive affective processes have been developed. Integrating these behavioural approaches with pharmacology and targeted brain manipulations, a picture is beginning to emerge of the underlying mechanisms that may link the pharmacology of antidepressants, these neuropsychological constructs and clinical efficacy. In this chapter, we discuss findings from animal studies, experimental medicine and patients investigating the neuropsychological effects of antidepressant drugs. We discuss the possible neural circuits that contribute to these effects and discuss whether a neuropsychological model of antidepressant effects could explain the temporal differences in clinical benefits observed with conventional delayed-onset antidepressants versus rapid-acting antidepressants.

β-glucan, a specific immuno-stimulant, produces rapid antidepressant effects by stimulating ERK1/2-dependent synthesis of BDNF in the hippocampus

A decline in microglia in the dentate gyrus of the hippocampus has recently been described as an important mechanism for the progression of depression. Reversal of this decline by innate immune system stimulants may represent a novel strategy to ameliorate the depressive phenotype in chronically stressed animals. β-glucan is a polysaccharide from Saccharomyces cerevisiae. It can efficiently stimulate microglia without inducing the production of pro-inflammatory cytokines. Therefore, β-glucan could be an ideal drug to ameliorate depressive phenotypes. In the present study, we found that a single injection of β-glucan reversed depression-like behaviors in mice induced by chronic unpredictable stress (CUS) in a dose-dependent manner, which was accompanied by a reversal of the CUS-induced decrease in brain-derived neurotrophic factor (BDNF) protein levels in the dentate gyrus. The crucial role of BDNF signaling in the antidepressant effect of β-glucan was demonstrated by experiments showing that infusion of an anti-BDNF antibody into dentate gyrus, construction of BDNF-Val68Met allele knock-in mice, or treatment with the BDNF receptor antagonist K252a abolished the antidepressant effect of β-glucan. The increased BDNF signaling induced by β-glucan was mediated by extracellular signal-regulated kinase1/2 (ERK1/2)-mediated BDNF synthesis, and inhibition of ERK1/2 by SL327 was able to abolish the antidepressant effect of β-glucan. Moreover, inhibition or depletion of microglia by minocycline or PLX3397 abolished the reversal effect of β-glucan on CUS-induced depression-like behaviors and CUS-induced impairment of ERK1/2-BDNF signaling. These results suggest that β-glucan exhibits antidepressant effects by stimulating microglia-mediated activation of ERK1/2 and synthesis of BDNF in the hippocampus.

The Impact of UFP-512 in Mice with Osteoarthritis Pain: The Role of Hydrogen Sulfide

The pain-relieving properties of opioids in inflammatory and neuropathic pain are heightened by hydrogen sulfide (H2S). However, whether allodynia and functional and/or emotional impairments related to osteoarthritis (OA) could be reduced by activating δ-opioid receptors (DOR) and the plausible influence of H2S on these actions has not been completely established. In female C57BL/6J mice with OA pain generated via monosodium acetate (MIA), we analyze: (i) the effects of UFP-512 (a DOR agonist), given alone and co-administered with two H2S donors, on the symptoms of allodynia, loss of grip strength (GS), and anxiodepressive-like comportment; (ii) the reversion of UFP-512 actions with naltrindole (a DOR antagonist), and (iii) the impact of UFP-512 on the expression of phosphorylated NF-kB inhibitor alpha (p-IKBα) and the antioxidant enzymes superoxide dismutase 1 (SOD-1) and glutathione sulfur transferase M1 (GSTM1); and the effects of H2S on DOR levels in the dorsal root ganglia (DRG), amygdala (AMG), and hippocampus (HIP) of MIA-injected animals. Results showed that systemic and local administration of UFP-512 dose-dependently diminished the allodynia and loss of GS caused by MIA, whose effects were potentiated by H2S and reversed by naltrindole. UFP-512 also inhibited anxiodepressive-like behaviors, normalized the overexpression of p-IKBα in DRG and HIP, and enhanced the expression of SOD-1 and GSTM1 in DRG, HIP, and/or AMG. Moreover, the increased expression of DOR triggered by H2S might support the improved analgesic actions of UFP-512 co-administered with H2S donors. This study proposes the use of DOR agonists, alone or combined with H2S donors, as a new treatment for OA pain.

The Role of BDNF and NPY Levels, Effects of Behavioral Systems and Emotion Regulation on Internet Addiction in Adolescents

Internet addiction (IA), one of the behavioral addictions, is also related to impulsivity. Although studies on its etiology and risks continue, the number of studies is limited. In this study, we aimed to assess the roles of behavioral systems, emotional regulation (ER), and impulsivity in the development of IA in adolescents and also to assess the relationship between all these clinical parameters and brain-derived neurotrophic factor (BDNF) and neuropeptide Y (NPY). Forty-two adolescents with IA and 30 healthy controls (ages 12 -17) were included in the study. Self-reported measures included the Internet Addiction Scale. (IAS), Behavioral Activation and Behavioral Inhibition Scale (BAS/BIS), Barratt. Impulsiveness Scale-11 (BIS-11), and Difficulties in Emotion Regulation Scale-16 (DERS-16) were used for the assessment of the participants. The levels of plasma brain BDNF and NPY were evaluated with the ELISA method. BAS/BIS subscale scores, BIS-11, and DERS-16 scale total scores were found to be statistically significantly higher, while BDNF and NPY levels were found to be lower in adolescents with IA compared to the healthy controls. IA severity was not found to correlate with both BDNF and NPY. IA was found to be more related to BIS than to BAS. There is a need for further studies evaluating developmental features and possible diagnostic biomarkers that may be associated with IA in adolescents.