Multi-systemic evaluation of biological and emotional responses to the Trier Social Stress Test: A meta-analysis and systematic review.

Humans experience multiple biological and emotional changes under acute stress. Adopting a multi-systemic approach, we summarized 61 studies on healthy people's endocrinological, physiological, immunological and emotional responses to the Trier Social Stress Test. We found salivary cortisol and negative mood states were the most sensitive markers to acute stress and recovery. Biomarkers such as heart rate and salivary alpha-amylase also showed sensitivity to acute stress, but the numbers of studies were small. Other endocrinological (e.g., dehydroepiandrosterone), inflammatory (C-Reactive Protein, Interleukin-6) and physiological (e.g., skin conductance level) measures received modest support as acute stress markers. Salivary cortisol showed some associations with mood measures (e.g., state anxiety) during acute stress and recovery, and heart rate showed preliminary positive relationship with calmness ratings during response to TSST, but the overall evidence was mixed. While further research is needed, these findings provide updated and comprehensive knowledge on the integrated psychobiological response profiles to TSST.

Sex-Specific Changes to Brain Fatty Acids, Plasmalogen, and Plasma Endocannabinoids in Offspring Exposed to Maternal and Postnatal High-Linoleic-Acid Diets.

Linoleic acid (LA) is required for neuronal development. We have previously demonstrated sex-specific changes in cardiovascular and hepatic function in rat offspring from mothers consuming a high-LA diet, with some effects associated with reduced LA concentration in the postnatal diet. At this time, the impact of a high-maternal-LA diet on offspring brain development and the potential for the postnatal diet to alter any adverse changes are unknown. Rat offspring from mothers fed low- (LLA) or high-LA (HLA) diets during pregnancy and lactation were weaned at postnatal day 25 (PN25) and fed LLA or HLA diets until sacrifice in adulthood (PN180). In the offspring's brains, the postnatal HLA diet increased docosapentaenoate in males. The maternal HLA diet increased LA, arachidonate, docosapentaenoate, C18:0 dimethylacetal (DMA), C16:0 DMA, C16:0 DMA/C16:0, and C18:0 DMA/C18:0, but decreased eoicosenoate, nervoniate, lignocerate, and oleate in males. Maternal and postnatal HLA diets reduced oleate and vaccenate and had an interaction effect on myristate, palmitoleate, and eicosapentaenoate in males. In females, maternal HLA diet increased eicosadienoate. Postnatal HLA diet increased stearate and docosapentaenoate. Maternal and postnatal HLA diets had an interaction effect on oleate, arachidate, and docosahexaenoic acid (DHA)/omega (n)-6 docosapentaenoic acid (DPA) in females. Postnatal HLA diet decreased DHA/n-6 DPA in males and females. Postnatal HLA diet increased plasma endocannabinoids (arachidonoyl ethanolamide and 2-arachidonoyl glycerol), as well as other N-acyl ethanolamides and testosterone. HLA diet alters brain fatty acids, plasma endocannabinoids, and plasmalogen concentrations in a development-specific and sex-specific manner.

Effects of exercise interventions on brain-derived neurotrophic factor levels in overweight and obesity: A systematic review and meta-analysis.

Background: /Objective. An explosion in global obesity epidemic poses threats to the healthcare system by provoking risks of many debilitating diseases, including cognitive dysfunction. Physical activity has been shown to alleviate the deleterious effects of obesity-associated cognitive deficits across the lifespan. Given the strong neuroprotective role of brain-derived neurotrophic factor (BDNF) and exercise training as a known modulator for its elevation, this systematic review sought to examine the strength of the association between exercise and BDNF levels in healthy people with overweight and obesity. Methods: Six electronic databases (PubMed, MEDLINE, EMBASE, Web of Science, Ovid Nursing Database, and SPORTDiscus) were searched from their inceptions through December 2022. The primary outcome of interest was BDNF levels. Interventional studies (randomized and quasi-experimental) with English full text available were included. Risk of bias of the included studies was assessed using the Physiotherapy Evidence Database Scale. Data were extracted for meta-analyses by random-effects models. Results: Thirteen studies (n = 750), of which 69.2% (9/13) had low risk of bias, were included. In the meta-analysis, exercise interventions had no significant effect on resting BDNF levels (standardized mean difference: -0.30, 95% CI -0.80 to 0.21, P = 0.25). Subgroup analyses also indicated no effects of age and types of control groups being compared on moderating the association. Conclusion: To further inform the role of BDNF in obesity-related cognitive functioning, rigorous studies with larger samples of participants and raw data available were imperatively deserved.

Comparative effectiveness of exercise, antidepressants and their combination in treating non-severe depression: a systematic review and network meta-analysis of randomised controlled trials.

OBJECTIVE: To assess the comparative effectiveness of exercise, antidepressants and their combination for alleviating depressive symptoms in adults with non-severe depression. DESIGN: Systematic review and network meta-analysis. DATA SOURCES: Embase, MEDLINE, PsycINFO, Cochrane Library, Web of Science, Scopus and SportDiscus. ELIGIBILITY CRITERIA: Randomised controlled trials (1990-present) that examined the effectiveness of an exercise, antidepressant or combination intervention against either treatment alone or a control/placebo condition in adults with non-severe depression. STUDY SELECTION AND ANALYSIS: Risk of bias, indirectness and the overall confidence in the network were assessed by two independent investigators. A frequentist network meta-analysis was performed to examine postintervention differences in depressive symptom severity between groups. Intervention drop-out was assessed as a measure of treatment acceptability. RESULTS: Twenty-one randomised controlled trials (n=2551) with 25 comparisons were included in the network. There were no differences in treatment effectiveness among the three main interventions (exercise vs antidepressants: standardised mean differences, SMD, -0.12; 95% CI -0.33 to 0.10, combination versus exercise: SMD, 0.00; 95% CI -0.33 to 0.33, combination vs antidepressants: SMD, -0.12; 95% CI -0.40 to 0.16), although all treatments were more beneficial than controls. Exercise interventions had higher drop-out rates than antidepressant interventions (risk ratio 1.31; 95% CI 1.09 to 1.57). Heterogeneity in the network was moderate (τ2=0.03; I2=46%). CONCLUSIONS: The results suggest no difference between exercise and pharmacological interventions in reducing depressive symptoms in adults with non-severe depression. These findings support the adoption of exercise as an alternative or adjuvant treatment for non-severe depression in adults. SYSTEMATIC REVIEW REGISTRATION: PROSPERO CRD4202122656.

Non-Invasive Brain Stimulation Effects on Biomarkers of Tryptophan Metabolism: A Scoping Review and Meta-Analysis.

Abnormal activation of the kynurenine and serotonin pathways of tryptophan metabolism is linked to a host of neuropsychiatric disorders. Concurrently, noninvasive brain stimulation (NIBS) techniques demonstrate high therapeutic efficacy across neuropsychiatric disorders, with indications for modulated neuroplasticity underlying such effects. We therefore conducted a scoping review with meta-analysis of eligible studies, conforming with the PRISMA statement, by searching the PubMed and Web of Science databases for clinical and preclinical studies that report the effects of NIBS on biomarkers of tryptophan metabolism. NIBS techniques reviewed were electroconvulsive therapy (ECT), transcranial magnetic stimulation (TMS), and transcranial direct current stimulation (tDCS). Of the 564 search results, 65 studies were included with publications dating back to 1971 until 2022. The Robust Bayesian Meta-Analysis on clinical studies and qualitative analysis identified general null effects by NIBS on biomarkers of tryptophan metabolism, but moderate evidence for TMS effects on elevating serum serotonin levels. We cannot interpret this as evidence for or against the effects of NIBS on these biomarkers, as there exists several confounding methodological differences in this literature. Future controlled studies are needed to elucidate the effects of NIBS on biomarkers of tryptophan metabolism, an under-investigated question with substantial implications to clinical research and practice.

In Pursuit of Healthy Aging: Effects of Nutrition on Brain Function.

Consuming a balanced, nutritious diet is important for maintaining health, especially as individuals age. Several studies suggest that consuming a diet rich in antioxidants and anti-inflammatory components such as those found in fruits, nuts, vegetables, and fish may reduce age-related cognitive decline and the risk of developing various neurodegenerative diseases. Numerous studies have been published over the last decade focusing on nutrition and how this impacts health. The main objective of the current article is to review the data linking the role of diet and nutrition with aging and age-related cognitive decline. Specifically, we discuss the roles of micronutrients and macronutrients and provide an overview of how the gut microbiota-gut-brain axis and nutrition impact brain function in general and cognitive processes in particular during aging. We propose that dietary interventions designed to optimize the levels of macro and micronutrients and maximize the functioning of the microbiota-gut-brain axis can be of therapeutic value for improving cognitive functioning, particularly during aging.

AdipoRon Treatment Induces a Dose-Dependent Response in Adult Hippocampal Neurogenesis.

AdipoRon, an adiponectin receptor agonist, elicits similar antidiabetic, anti-atherogenic, and anti-inflammatory effects on mouse models as adiponectin does. Since AdipoRon can cross the blood-brain barrier, its chronic effects on regulating hippocampal function are yet to be examined. This study investigated whether AdipoRon treatment promotes hippocampal neurogenesis and spatial recognition memory in a dose-dependent manner. Adolescent male C57BL/6J mice received continuous treatment of either 20 mg/kg (low dose) or 50 mg/kg (high dose) AdipoRon or vehicle intraperitoneally for 14 days, followed by the open field test to examine anxiety and locomotor activity, and the Y maze test to examine hippocampal-dependent spatial recognition memory. Immunopositive cell markers of neural progenitor cells, immature neurons, and newborn cells in the hippocampal dentate gyrus were quantified. Immunosorbent assays were used to measure the serum levels of factors that can regulate hippocampal neurogenesis, including adiponectin, brain-derived neurotrophic factor (BDNF), and corticosterone. Our results showed that 20 mg/kg AdipoRon treatment significantly promoted hippocampal cell proliferation and increased serum levels of adiponectin and BDNF, though there were no effects on spatial recognition memory and locomotor activity. On the contrary, 50 mg/kg AdipoRon treatment impaired spatial recognition memory, suppressed cell proliferation, neuronal differentiation, and cell survival associated with reduced serum levels of BDNF and adiponectin. The results suggest that a low-dose AdipoRon treatment promotes hippocampal cell proliferation, while a high-dose AdipoRon treatment is detrimental to the hippocampus function.

Inflammation, brain structure and cognition interrelations among individuals with differential risks for bipolar disorder.

Neuro-inflammation might impact on clinical manifestations and cognition function via changing the volumes of key brain structures such as the anterior cingulate cortex (ACC) in bipolar disorder (BD). In this study, we investigated the interrelations among interleukin (IL)-6 cytokine level, grey matter (GM) volume of the anterior cingulated cortex (ACC), and attention function among offspring of parents diagnosed with BD. The offspring were categorized as being either asymptomatic or symptomatic based on whether they manifested pre-defined sub-threshold mood symptoms. We found that the symptomatic offspring showed significantly higher serum levels of IL-6 than the asymptomatic offspring (F(1, 59) = 67.65, p < 0.001). On the brain level, we obtained significant interactive effect of group and IL6 level on the ACC GM (PFWE = 0.017). Specifically, the GM volume of the rostral ACC was negatively associated with the levels of IL-6 in the asymptomatic offspring (PFWE = 0.021), but not the symptomatic offspring (PFWE > 0.05). Mediation analyses revealed that the GM volume of the rostral ACC significantly mediated the negative association between the IL-6 levels and attention performance in the asymptomatic offspring (bootstrapping Confidence Interval (CI) = -6.0432 to -0.0731) but not the symptomatic offspring (bootstrapping CI = -0.3197 to 1.3423). Our data suggest that the asymptomatic and symptomatic bipolar offspring may exhibit different neurocognitive-inflammatory profiles, which could be further validated as viable biosignatures for BD risk and resilience.

Role of omega-6 and omega-3 fatty acids in fetal programming.

Maternal nutrition plays a critical role in fetal development and can influence adult onset of disease. Linoleic acid (LA) and alpha-linolenic acid (ALA) are major omega-6 (n-6) and n-3 polyunsaturated fatty acids (PUFA), respectively, that are essential in our diet. LA and ALA are critical for the development of the fetal neurological and immune systems. However, in recent years, the consumption of n-6 PUFA has increased gradually worldwide, and elevated n-6 PUFA consumption may be harmful to human health. Consumption of diets with high levels of n-6 PUFA before or during pregnancy may have detrimental effects on fetal development and may influence overall health of offspring in adulthood. This review discusses the role of n-6 PUFA in fetal programming, the importance of a balance between n-6 and n-3 PUFAs in the maternal diet, and the need of further animal models and human studies that critically evaluate both n-6 and n-3 PUFA contents in diets.

Learning to prescribe and instruct exercise in physiotherapy education through authentic continuous assessment and rubrics.

BACKGROUND: Authentic assessment and effective feedback are among various strategies that promote learning in the assessment process. These strategies are commonly used during clinical placements. However, they are rarely implemented in the didactic portion of physiotherapy education despite the benefits this type of assessment may bring to achieving students' learning and outcome. METHODS: This mixed method study investigated how an authentic continuous assessment coupled with rubrics facilitated physiotherapy students' learning process in a real-life complex skill of exercise prescription and instruction. The study also explored the relationship between different activities in the Learning Management System (LMS) and learning outcomes. Qualitative data was collected using a focus group and an analysis of discussion forum posts. Quantitative data included various information from a questionnaire, the LMS and assessment score. RESULTS: Thematic analyses from the focus group and discussion forum posts suggest that students used a cyclical self-regulated learning process as a result of authentic task design and rubrics for feedback facilitation. Interestingly, the discussion forum access was found to be moderately and significantly correlated with assessment score by Spearman's rank correlation (ρ = 0.59, p < 0.01), while the students did not find the discussion forum useful. CONCLUSIONS: Overall results suggest the promotion of self-regulated learning in this authentic continuous assessment. The roles and goals of each authentic task within the assessment should be made explicit in order to raise cognitive awareness of benefits.

From Obesity to Hippocampal Neurodegeneration: Pathogenesis and Non-Pharmacological Interventions.

High-caloric diet and physical inactivity predispose individuals to obesity and diabetes, which are risk factors of hippocampal neurodegeneration and cognitive deficits. Along with the adipose-hippocampus crosstalk, chronically inflamed adipose tissue secretes inflammatory cytokine could trigger neuroinflammatory responses in the hippocampus, and in turn, impairs hippocampal neuroplasticity under obese and diabetic conditions. Hence, caloric restriction and physical exercise are critical non-pharmacological interventions to halt the pathogenesis from obesity to hippocampal neurodegeneration. In response to physical exercise, peripheral organs, including the adipose tissue, skeletal muscles, and liver, can secret numerous exerkines, which bring beneficial effects to metabolic and brain health. In this review, we summarized how chronic inflammation in adipose tissue could trigger neuroinflammation and hippocampal impairment, which potentially contribute to cognitive deficits in obese and diabetic conditions. We also discussed the potential mechanisms underlying the neurotrophic and neuroprotective effects of caloric restriction and physical exercise by counteracting neuroinflammation, plasticity deficits, and cognitive impairments. This review provides timely insights into how chronic metabolic disorders, like obesity, could impair brain health and cognitive functions in later life.

The Novel Perspectives of Adipokines on Brain Health.

First seen as a fat-storage tissue, the adipose tissue is considered as a critical player in the endocrine system. Precisely, adipose tissue can produce an array of bioactive factors, including cytokines, lipids, and extracellular vesicles, which target various systemic organ systems to regulate metabolism, homeostasis, and immune response. The global effects of adipokines on metabolic events are well defined, but their impacts on brain function and pathology remain poorly defined. Receptors of adipokines are widely expressed in the brain. Mounting evidence has shown that leptin and adiponectin can cross the blood-brain barrier, while evidence for newly identified adipokines is limited. Significantly, adipocyte secretion is liable to nutritional and metabolic states, where defective circuitry, impaired neuroplasticity, and elevated neuroinflammation are symptomatic. Essentially, neurotrophic and anti-inflammatory properties of adipokines underlie their neuroprotective roles in neurodegenerative diseases. Besides, adipocyte-secreted lipids in the bloodstream can act endocrine on the distant organs. In this article, we have reviewed five adipokines (leptin, adiponectin, chemerin, apelin, visfatin) and two lipokines (palmitoleic acid and lysophosphatidic acid) on their roles involving in eating behavior, neurotrophic and neuroprotective factors in the brain. Understanding and regulating these adipokines can lead to novel therapeutic strategies to counteract metabolic associated eating disorders and neurodegenerative diseases, thus promote brain health.

Physical exercise-induced hippocampal neurogenesis and antidepressant effects are mediated by the adipocyte hormone adiponectin.

Adiponectin (ADN) is an adipocyte-secreted protein with insulin-sensitizing, antidiabetic, antiinflammatory, and antiatherogenic properties. Evidence is also accumulating that ADN has neuroprotective activities, yet the underlying mechanism remains elusive. Here we show that ADN could pass through the blood-brain barrier, and elevating its levels in the brain increased cell proliferation and decreased depression-like behaviors. ADN deficiency did not reduce the basal hippocampal neurogenesis or neuronal differentiation but diminished the effectiveness of exercise in increasing hippocampal neurogenesis. Furthermore, exercise-induced reduction in depression-like behaviors was abrogated in ADN-deficient mice, and this impairment in ADN-deficient mice was accompanied by defective running-induced phosphorylation of AMP-activated protein kinase (AMPK) in the hippocampal tissue. In vitro analyses indicated that ADN itself could increase cell proliferation of both hippocampal progenitor cells and Neuro2a neuroblastoma cells. The neurogenic effects of ADN were mediated by the ADN receptor 1 (ADNR1), because siRNA targeting ADNR1, but not ADNR2, inhibited the capacity of ADN to enhance cell proliferation. These data suggest that adiponectin may play a significant role in mediating the effects of exercise on hippocampal neurogenesis and depression, possibly by activation of the ADNR1/AMPK signaling pathways, and also raise the possibility that adiponectin and its agonists may represent a promising therapeutic treatment for depression.

Involvement of Adult Hippocampal Neurogenesis in Learning and Forgetting.

Adult hippocampal neurogenesis is a process involving the continuous generation of newborn neurons in the hippocampus of adult animals. Mounting evidence has suggested that hippocampal neurogenesis contributes to some forms of hippocampus-dependent learning and memory; however, the detailed mechanism concerning how this small number of newborn neurons could affect learning and memory remains unclear. In this review, we discuss the relationship between adult-born neurons and learning and memory, with a highlight on recently discovered potential roles of neurogenesis in pattern separation and forgetting.

A refined formula derived from Jiawei-Xiaoyao pill exerts rapid antidepressant-like effects in LPS-induced depression by reducing neuroinflammation and restoring neuroplasticity signaling.

ETHNOPHARMACOLOGICAL RELEVANCE: Jiawei-Xiaoyao Pill (JWX), a classic formula in traditional Chinese medicine, is derived from Xiaoyao Pill by adding significant amounts of Gardeniae Fructus (GF) and Moutan Cortex (MC). It is frequently used for the treatment of depression. JWX has been demonstrated to uniquely elicit rapid antidepressant-like effects within the prescribed dosage range. To date, GF has been shown to have rapid antidepressant-like effects, but a much higher dose is required than its proportion in JWX. It is assumed that the synergism of GF with a minimum number of other herbs in JWX serves as a refined formula that exerts these rapid antidepressant-like effects. Identification of a refined formula is important for prioritizing the herbs and ingredients to optimize the quality control of JWX. However, such a refined formula for JWX has not been identified yet. AIM OF THE STUDY: Here we aimed to identify a refined formula derived from JWX for optimized rapid antidepressant-like effects. Since the neuroinflammation mechanism involving in depression treatment has not been previously investigated for JWX, we tested the mechanism for both JWX and the refined formula. MATERIALS AND METHODS: Individual herbs (MC; ASR, Angelica Sinensis Radix; Bupleuri Radix; Paeonia Radix Alba) that show antidepressant-like responses were mixed with GF at the proportional dosage in JWX to identify the refined formula. Rapid antidepressant-like effects were assessed by using NSF (Novelty Suppressed Feeding Test) and other behavioral tests following a single administration. The identified formula was further tested in a lipopolysaccharide (LPS)-induced depressive model, and the molecular signaling mechanisms were investigated using Western blot analysis, immunofluorescence, and pharmacological inhibition of mTOR signaling. Scopolamine (Scop) was used as a positive control for induction of rapid antidepressant effects. RESULTS: A combination of GF, MC and ASR (GMA) at their dosages proportional to JWX induced behavioral signs of rapid antidepressant-like responses in both normal and LPS-treated mice, with the antidepressant-like effects sustained for 5 d. Similar to JWX or Scop, GMA rapidly reduced the neuroinflammation signaling of Iba-1-NF-кB, enhanced neuroplasticity signaling of CaMKII-mTOR-BDNF, and attenuated the upregulated expressions of the NMDAR sub-units GluN1 and GluN2B in the hippocampus of LPS-treated mice. GMA, JWX and Scop rapidly restored the number of BDNF-positive cells reduced by LPS treatment in the CA3 region of the hippocampus. Furthermore, rapamycin, a selective inhibitor of mTOR, blunted the rapid antidepressant-like effects and hippocampal BDNF signaling upregulation by GMA. CONCLUSION: GMA may serve as a refined formula from JWX, capable of inducing rapid antidepressant-like effects. In the LPS-induced depression model, the effects of GMA were mediated via rapidly alleviating neuroinflammation and enhancing neuroplasticity.

Hippocampal PACAP signaling activation triggers a rapid antidepressant response.

BACKGROUND: The development of ketamine-like rapid antidepressants holds promise for enhancing the therapeutic efficacy of depression, but the underlying cellular and molecular mechanisms remain unclear. Implicated in depression regulation, the neuropeptide pituitary adenylate cyclase-activating polypeptide (PACAP) is investigated here to examine its role in mediating the rapid antidepressant response. METHODS: The onset of antidepressant response was assessed through depression-related behavioral paradigms. The signaling mechanism of PACAP in the hippocampal dentate gyrus (DG) was evaluated by utilizing site-directed gene knockdown, pharmacological interventions, or optogenetic manipulations. Overall, 446 mice were used for behavioral and molecular signaling testing. Mice were divided into control or experimental groups randomly in each experiment, and the experimental manipulations included: chronic paroxetine treatments (4, 9, 14 d) or a single treatment of ketamine; social defeat or lipopolysaccharides-injection induced depression models; different doses of PACAP (0.4, 2, 4 ng/site; microinjected into the hippocampal DG); pharmacological intra-DG interventions (CALM and PACAP6-38); intra-DG viral-mediated PACAP RNAi; and opotogenetics using channelrhodopsins 2 (ChR2) or endoplasmic natronomonas halorhodopsine 3.0 (eNpHR3.0). Behavioral paradigms included novelty suppressed feeding test, tail suspension test, forced swimming test, and sucrose preference test. Western blotting, ELISA, or quantitative real-time PCR (RT-PCR) analysis were used to detect the expressions of proteins/peptides or genes in the hippocampus. RESULTS: Chronic administration of the slow-onset antidepressant paroxetine resulted in an increase in hippocampal PACAP expression, and intra-DG blockade of PACAP attenuated the onset of the antidepressant response. The levels of hippocampal PACAP expression were reduced in both two distinct depression animal models and intra-DG knockdown of PACAP induced depression-like behaviors. Conversely, a single infusion of PACAP into the DG region produced a rapid and sustained antidepressant response in both normal and chronically stressed mice. Optogenetic intra-DG excitation of PACAP-expressing neurons instantly elicited antidepressant responses, while optogenetic inhibition induced depression-like behaviors. The longer optogenetic excitation/inhibition elicited the more sustained antidepressant/depression-like responses. Intra-DG PACAP infusion immediately facilitated the signaling for rapid antidepressant response by inhibiting calcium/calmodulin-dependent protein kinase II (CaMKII)-eukaryotic elongation factor 2 (eEF2) and activating the mammalian target of rapamycin (mTOR). Pre-activation of CaMKII signaling within the DG blunted PACAP-induced rapid antidepressant response as well as eEF2-mTOR-brain-derived neurotrophic factor (BDNF) signaling. Finally, acute ketamine treatment upregulated hippocampal PACAP expression, whereas intra-DG blockade of PACAP signaling attenuated ketamine's rapid antidepressant response. CONCLUSIONS: Activation of hippocampal PACAP signaling induces a rapid antidepressant response through the regulation of CaMKII inhibition-governed eEF2-mTOR-BDNF signaling.

Sex differences in brain excitability revealed by concurrent iTBS/fNIRS.

Sex differences have been claimed an imperative factor in the optimization of psychiatric treatments. Intermittent theta-burst stimulation (iTBS), a patterned form of repetitive transcranial magnetic stimulation, is a promising non-invasive treatment option. Here, we investigated whether the real-time neural response to iTBS differs between men and women, and which mechanisms may mediate these differences. To this end, we capitalized on a concurrent iTBS/functional near-infrared spectroscopy setup over the left dorsolateral prefrontal cortex, a common clinical target, to test our assumptions. In a series of experiments, we show (1) a biological sex difference in absolute hemoglobin concentrations in the left dorsolateral prefrontal cortex in healthy participants; (2) that this sex difference is amplified by iTBS but not by cognitive tasks; and (3) that the sex difference amplified by iTBS is modulated by stimulation intensity. These results inform future stimulation treatment optimizations towards precision psychiatry.

Effect of exercise interventions on brain-derived neurotrophic factor expression in people with overweight and obesity: protocol for a systematic review and meta-analysis.

INTRODUCTION: Epidemic obesity ('globobesity') has led to a considerable rise in the prevalence and incidence of many disabling conditions, including cognitive dysfunction. Recent evidence has suggested that habitual exercise can alleviate the deleterious effects of obesity on cognitive functioning across the lifespan. Given that there is a potential link among obesity, exercise, cognitive health and brain-derived neurotrophic factor (BDNF), this systematic review aims to critically appraise interventional trials on exercise and BDNF and to estimate the pooled effect of exercise training on BDNF levels among healthy individuals with overweight and obesity. METHODS AND ANALYSIS: Six electronic databases-PubMed, MEDLINE, EMBASE, Web of Science, Ovid Nursing Database and SPORTDiscus-will be searched from their inception through December 2022. Only interventional studies, including randomised controlled trials and quasi-experimental studies, with full text available and reported in English will be included. The primary outcomes will be changes in BDNF levels among healthy subjects with overweight and obesity following either acute or chronic bouts of exercise interventions. Two reviewers will independently conduct data extraction and risk of bias assessment for included trials using the Physiotherapy Evidence Database Scale. We will produce a narrative synthesis, with findings categorised by sex, age groups and types of exercise training. Data will be extracted and pooled for meta-analyses using random-effects models. ETHICS AND DISSEMINATION: No formal ethical approval is required for this systematic review. The findings of this review will be disseminated through peer-reviewed publications. PROSPERO REGISTRATION NUMBER: CRD42023414868.

Increasing Adiponectin Signaling by Sub-Chronic AdipoRon Treatment Elicits Antidepressant- and Anxiolytic-Like Effects Independent of Changes in Hippocampal Plasticity.

(1) Background: Adiponectin is an adipocyte-secreted hormone that has antidepressant- and anxiolytic-like effects in preclinical studies. Here, we investigated the antidepressant- and anxiolytic-like effects of sub-chronic treatment with AdipoRon, an adiponectin receptor agonist, and its potential linkage to changes in hippocampal adult neurogenesis and synaptic plasticity. (2) Methods: Different cohorts of wild-type C57BL/6J and CamKIIα-Cre male mice were treated with sub-chronic (7 days) AdipoRon, followed by behavioral, molecular, and electrophysiological experiments. (3) Results: 7-day AdipoRon treatment elicited antidepressant- and anxiolytic-like effects but did not affect hippocampal neurogenesis. AdipoRon treatment reduced hippocampal brain-derived neurotrophic factor (BDNF) levels, neuronal activation in the ventral dentate gyrus, and long-term potentiation of the perforant path. The knockdown of N-methyl-D-aspartate (NMDA) receptor subunits GluN2A and GluN2B in the ventral hippocampus did not affect the antidepressant- and anxiolytic-like effects of AdipoRon. (4) Conclusions: Increasing adiponectin signaling through sub-chronic AdipoRon treatment results in antidepressant- and anxiolytic-like effects independent of changes in hippocampal structural and synaptic function.

Leveraging the glymphatic and meningeal lymphatic systems as therapeutic strategies in Alzheimer's disease: an updated overview of nonpharmacological therapies.

Understanding and treating Alzheimer's disease (AD) has been a remarkable challenge for both scientists and physicians. Although the amyloid-beta and tau protein hypothesis have largely explained the key pathological features of the disease, the mechanisms by which such proteins accumulate and lead to disease progression are still unknown. Such lack of understanding disrupts the development of disease-modifying interventions, leaving a therapeutic gap that remains unsolved. Nonetheless, the recent discoveries of the glymphatic pathway and the meningeal lymphatic system as key components driving central solute clearance revealed another mechanism underlying AD pathogenesis. In this regard, this narrative review integrates the glymphatic and meningeal lymphatic systems as essential components involved in AD pathogenesis. Moreover, it discusses the emerging evidence suggesting that nutritional supplementation, non-invasive brain stimulation, and traditional Chinese medicine can improve the pathophysiology of the disease by increasing glymphatic and/or meningeal lymphatic function. Given that physical exercise is a well-regarded preventive and pro-cognitive intervention for dementia, we summarize the evidence suggesting the glymphatic system as a mediating mechanism of the physical exercise therapeutic effects in AD. Targeting these central solute clearance systems holds the promise of more effective treatment strategies.