Circulating cortisol and cognitive and structural brain measures: The Framingham Heart Study

Computer Programming E-Learners' Personality Traits, Self-Reported Cognitive Abilities, and Learning Motivating Factors

Educational systems around the world encourage students to engage in programming activities, but programming learning is one of the most challenging learning tasks. Thus, it was significant to explore the factors related to programming learning. This study aimed to identify computer programming e-learners’ personality traits, self-reported cognitive abilities and learning motivating factors in comparison with other e-learners. We applied a learning motivating factors questionnaire, the Big Five Inventory—2, and the SRMCA instruments. The sample consisted of 444 e-learners, including 189 computer programming e-learners, the mean age was 25.19 years. It was found that computer programming e-learners demonstrated significantly lower scores of extraversion, and significantly lower scores of motivating factors of individual attitude and expectation, reward and recognition, and punishment. No significant differences were found in the scores of self-reported cognitive abilities between the groups. In the group of computer programming e-learners, extraversion was a significant predictor of individual attitude and expectation; conscientiousness and extraversion were significant predictors of challenging goals; extraversion and agreeableness were significant predictors of clear direction; open-mindedness was a significant predictor of a diminished motivating factor of punishment; negative emotionality was a significant predictor of social pressure and competition; comprehension-knowledge was a significant predictor of individual attitude and expectation; fluid reasoning and comprehension-knowledge were significant predictors of challenging goals; comprehension-knowledge was a significant predictor of clear direction; and visual processing was a significant predictor of social pressure and competition. The SEM analysis demonstrated that personality traits (namely, extraversion, conscientiousness, and reverted negative emotionality) statistically significantly predict learning motivating factors (namely, individual attitude and expectation, and clear direction), but the impact of self-reported cognitive abilities in the model was negligible in both groups of participants and non-participants of e-learning based computer programming courses; χ² (34) = 51.992, p = 0.025; CFI = 0.982; TLI = 0.970; NFI = 0.950; RMSEA = 0.051 [0.019–0.078]; SRMR = 0.038. However, as this study applied self-reported measures, we strongly suggest applying neurocognitive methods in future research.

Hydrolyzed Chicken Meat Extract Attenuates Neuroinflammation and Cognitive Impairment in Middle-Aged Mouse by Regulating M1/M2 Microglial Polarization

Aging is the most common cause of several neurodegenerative disorders, such as Alzheimer's disease and Parkinson's disease. The pathological hallmarks of age-dependent neuropathology consist of chronic neuroinflammation, oxidative stress, gliosis, learning disability, and cognitive decline. A novel hydrolyzed bioactive peptide mixture extracted from chicken meat, that is, hydrolyzed chicken extract (HCE) has been previously demonstrated to exert neuroprotective effects in rodents and humans. However, the mechanism of HCE on age-related neurological disorders remains unclear. Herein, we aimed to clarify the impact and mechanism of isolated bioactive components (BCs) from HCE on age-dependent neuroinflammation and cognitive impairment in middle-aged mice. We found that both BC and HCE supplementation ameliorated age-induced memory loss, alleviated hippocampal neuroinflammation and oxidative stress, followed by promoting hippocampal neurogenesis in mice. BC and HCE treatment also ameliorated age-dependent morphological anomalies and alleviated microgliosis and astrogliosis. In parallel, BC and HCE treatment showed a significant decrease in the NF-κB p65 and p38 MAPK signaling, which were associated with the enhancement of antioxidative enzymes activities. Furthermore, BC treatment attenuated the neuroinflammatory phenotypes by the decrease in M1-polarized microglia and the increase in M2-polarized microglia in vivo and in vitro. In addition, we found that cyclo(Phe-Phe), one of the cyclopeptides purified from BC, showed notable anti-inflammatory effects in BV2 cells. Taken together, BC might be used as a dietary supplement for alleviating age-dependent neuropathology in middle-aged individuals.

Diagnosis and Treatment Effect of Convolutional Neural Network-Based Magnetic Resonance Image Features on Severe Stroke and Mental State

The purpose of this paper is to explore the impact of magnetic resonance imaging (MRI) image features based on convolutional neural network (CNN) algorithm and conditional random field on the diagnosis and mental state of patients with severe stroke. 208 patients with severe stroke who all received MRI examination were recruited as the research objects. According to cerebral small vascular disease (CSVD) score, the patients were divided into CSVD 0∼4 groups. The patients who completed the three-month follow-up were classified into cognitive impairment group (124 cases) and the noncognitive impairment group (84 cases) according to the cut-off point of the Montreal cognitive assessment (MOCA) scale score of 26. A novel image segmentation algorithm was proposed based on U-shaped fully CNN (U-Net) and conditional random field, which was compared with the fully CNN (FCN) algorithm and U-Net algorithm, and was applied to the MRI segmentation training of patients with severe stroke. It was found that the average symmetric surface distance (ASSD) (3.13 ± 1.35), Hoffman distance (HD) (28.71 ± 9.05), Dice coefficient (0.78 ± 1.35), accuracy (0.74 ± 0.11), and sensitivity (0.85 ± 0.13) of the proposed algorithm were superior to those of FCN algorithm and U-Net algorithm. There were significant differences in the MOCA scores among the five groups of patients from CSVD 0 to CSVD 4 in the three time periods (0, 1, and 3 months) (P < 0.05). Differences in cerebral microhemorrhage (CMB), perivascular space (PVS), and number of cavities, Fazekas, and total CSVD scores between the two groups were significant (P < 0.05). Multivariate regression found that the number of PVS, white matter hyperintensity (WMH) Fazekas, and total CSVD score were independent factors of cognitive impairment. In short, MRI images based on deep learning image segmentation algorithm had good application value for clinical diagnosis and treatment of stroke and can effectively improve the detection effect of brain domain characteristics and psychological state of patients after stroke.

Sex-specific Changes in Brain Estrogen Metabolism Induced by Acute Trimethyltin Exposure

BACKGROUND/AIM

In this study, we investigated sex-specific effects of acute exposure to trimethyltin, a known neurotoxicant on metabolic steroids.

MATERIALS AND METHODS

We administered intraperitoneally 2.3 mg/kg trimethyltin to 4-week-old male mice and measured the levels of metabolic steroids 24 h after treatment. We also measured mRNA and protein levels of cytochrome P450 1B1 using real-time polymerase chain reaction and western blotting.

RESULTS

Cortisol levels in the cortex increased in both sexes following acute trimethyltin exposure. The estradiol levels decreased, and the 4-hydroxyestradiol levels increased only in females. We also observed increased cytochrome P450 1B1 mRNA and protein levels only in the female cortex.

CONCLUSION

Acute trimethyltin exposure induces distinct sex-specific metabolic changes in the brain before significant sexual maturation.

Facility-based and home-based multidomain interventions including cognitive training, exercise, diet, vascular risk management, and motivation for older adults: a randomized controlled feasibility trial

We aimed to evaluate the feasibility of multidomain intervention (MI) tailored to the Korean context. In an outcome assessor-blinded, randomized controlled trial, participants without dementia and with one or more modifiable dementia risk factors, aged 60-79 years, were randomly assigned to the facility-based MI (FMI; n=51), the home-based MI (HMI; n=51), or the control group receiving general health advice (n=50). The 24-week intervention comprised vascular risk management, cognitive training, social activity, physical exercise, nutrition guidance, and motivational enhancement. The FMI participants performed all intervention programs at a facility three times a week. The HMI participants performed some programs at a facility once every 1-2 weeks and performed others at home. The primary outcome was feasibility measured through retention, adherence, and at least no differences from the control group in the Repeatable Battery for the Assessment of Neuropsychological Status (RBANS). In the FMI and HMI groups, the retention rates were 88.2% and 96.1%, and adherence to the intervention was 94.5% and 96.8%, respectively. The RBANS total scale index score improved significantly in the FMI (5.46 ± 7.50, P = 0.004) and HMI (5.50 ± 8.14, P = 0.004) groups compared to the control group (-0.74 ± 11.51). The FMI and HMI are feasible and there are indicators of efficacy.

The old guard: Age-related changes in microglia and their consequences

Among all major organs, the brain is one of the most susceptible to the inexorable effects of aging. Throughout the last decades, several studies in human cohorts and animal models have revealed a plethora of age-related changes in the brain, including reduced neurogenesis, oxidative damage, mitochondrial dysfunction and cell senescence. As the main immune effectors and first responders of the nervous tissue, microglia are at the center of these events. These cells experience irrevocable changes as a result from cumulative exposure to environmental triggers, such as stress, infection and metabolic dysregulation. The age-related immunosenescent phenotype acquired by microglia is characterized by profound modifications in their transcriptomic profile, secretome, morphology and phagocytic activity, which compromise both their housekeeping and defensive functions. As a result, aged microglia are no longer capable of establishing effective immune responses and sustaining normal synaptic activity, directly contributing to age-associated cognitive decline and neurodegeneration. This review discusses how lifestyle and environmental factors drive microglia dysfunction at the molecular and functional level, also highlighting possible interventions to reverse aging-associated damage to the nervous and immune systems.

Psychobiological mechanisms underlying the mood benefits of meditation: A narrative review

Psychological stressors can lead to distress and result in autonomic arousal and activation of a stress response. Ongoing or persistent stress can disrupt the stress response feedback mechanisms and result in elevated cortisol and pro-inflammatory cytokines which can cause damage to brain regions involved in the regulation of mood and emotion. We propose that the magnitude of the stress response experienced in response to psychological stressors depends on a number of modifiable psychological processes including an individual’s level of self-compassion, dispositional mindfulness, tendency to ruminate and attentional bias. We further propose that the stress response elected by psychological stressors can be meditated by influencing these modifiable psychological processes, and that meditation practices can decrease stress and improve mood by decreasing stress reactivity on a psychological, physiological and neurobiological level. We explore this in a narrative review.

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Meditation decreases blood pressure, heart rate, cortisol and cytokine levels.

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Meditation increases self-compassion, dispositional mindfulness and meta-cognition.

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Meditation improves attention and memory.

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Meditation results in brain changes in regions related to emotion regulation.

Mindfulness and Other Simple Neuroscience-Based Proposals to Promote the Learning Performance and Mental Health of Students during the COVID-19 Pandemic

The COVID-19 pandemic has had a negative impact on education. The restrictions imposed have undoubtedly led to impairment of the psychological well-being of both teachers and students, and of the way they experience interpersonal relationships. As reported previously in the literature, adverse effects such as loneliness, anxiety, and stress have resulted in a decrease in the cognitive performance of school and higher education students. Therefore, the objective of this work is to present a general overview of the reported adverse effects of the COVID-19 pandemic which may potentially influence the learning performance of students. Some neuroscientific findings related to memory and cognition, such as neuroplasticity and long-term potentiation, are also shown. We also discuss the positive effects of the practice of mindfulness, as well as other simple recommendations based on neuroscientific findings such as restful sleep, physical activity, and nutrition, which can act on memory and cognition. Finally, we propose some practical recommendations on how to achieve more effective student learning in the context of the pandemic. The aim of this review is to provide some assistance in this changing and uncertain situation in which we all find ourselves, and we hope that some of the information could serve as a starting point for hypotheses to be tested in educational research and their association with neuroscience.

Circadian fluctuations in glucocorticoid level predict perceptual discrimination sensitivity

Slow neurobiological rhythms, such as the circadian secretion of glucocorticoid (GC) hormones, modulate a variety of body functions. Whether and how endocrine fluctuations also exert an influence on perceptual abilities is largely uncharted. Here, we show that phasic increases in GC availability prove beneficial to auditory discrimination. In an age-varying sample of N = 68 healthy human participants, we characterize the covariation of saliva cortisol with perceptual sensitivity in an auditory pitch discrimination task at five time points across the sleep-wake cycle. First, momentary saliva cortisol levels were captured well by the time relative to wake-up and overall sleep duration. Second, within individuals, higher cortisol levels just prior to behavioral testing predicted better pitch discrimination ability, expressed as a steepened psychometric curve. This effect of GCs held under a set of statistical controls. Our results pave the way for more in-depth studies on neuroendocrinological determinants of sensory encoding and perception.

Ambient air pollutants are associated with morning serum cortisol in overweight and obese Latino youth in Los Angeles

BACKGROUND

Hypothalamic-pituitary-adrenal (HPA)-axis dysfunction has been associated with a variety of mental health and cardio-metabolic disorders. While causal models of HPA-axis dysregulation have been largely focused on either pre-existing health conditions or psychosocial stress factors, recent evidence suggests a possible role for central nervous system activation via air pollutants, such as nitrogen dioxide (NO2), ozone (O3) and particulate matter (PM). Therefore, in an observational study of Latino youth, we investigated if monthly ambient NO2, O3, and PM with aerodynamic diameter ≤ 2.5 (PM2.5) exposure were associated with morning serum cortisol levels.

METHODS

In this cross-sectional study, morning serum cortisol level was assessed after a supervised overnight fast in 203 overweight and obese Latino children and adolescents (female/male: 88/115; mean age: 11.1 ± 1.7 years; pre-pubertal/pubertal/post-pubertal: 85/101/17; BMI z-score: 2.1 ± 0.4). Cumulative concentrations of NO2, O3 and PM2.5 were spatially interpolated at the residential addresses based on measurements from community monitors up to 12 months prior to testing. Single and multi-pollutant linear effects models were used to test the cumulative monthly lag effects of NO2, O3, and PM2.5 on morning serum cortisol levels after adjusting for age, sex, seasonality, social position, pubertal status, and body fat percent by DEXA.

RESULTS

Single and multi-pollutant models showed that higher O3 exposure (derived from maximum 8-h exposure windows) in the prior 1-7 months was associated with higher serum morning cortisol (p < 0.05) and longer term PM2.5 exposure (4-10 months) was associated with lower serum morning cortisol levels (p < 0.05). Stratification by pubertal status showed associations in pre-pubertal children compared to pubertal and post-pubertal children. Single, but not multi-pollutant, models showed that higher NO2 over the 4-10 month exposure period associated with lower morning serum cortisol (p < 0.05).

CONCLUSIONS

Chronic ambient NO2, O3 and PM2.5 differentially associate with HPA-axis dysfunction, a mechanism that may serve as an explanatory pathway in the relationship between ambient air pollution and metabolic health of youth living in polluted urban environments. Further research that uncovers how ambient air pollutants may differentially contribute to HPA-axis dysfunction are warranted.

Sex-related Differences in Stress Reactivity and Cingulum White Matter

The prefrontal cortex and limbic system are important components of the neural circuit that underlies stress and anxiety. These brain regions are connected by white matter tracts that support neural communication including the cingulum, uncinate fasciculus, and the fornix/stria-terminalis. Determining the relationship between stress reactivity and these white matter tracts may provide new insight into factors that underlie stress susceptibility and resilience. Therefore, the present study investigated sex differences in the relationship between stress reactivity and generalized fractional anisotropy (GFA) of the white matter tracts that link the prefrontal cortex and limbic system. Diffusion weighted images were collected and deterministic tractography was completed in 104 young adults (55 men, 49 women; mean age = 18.87 SEM = 0.08). Participants also completed self-report questionnaires (e.g., Trait Anxiety) and donated saliva (later assayed for cortisol) before, during, and after the Trier Social Stress Test. Results revealed that stress reactivity (area under the curve increase in cortisol) and GFA of the cingulum bundle varied by sex. Specifically, men demonstrated greater cortisol reactivity and greater GFA within the cingulum than women. Further, an interaction between sex, stress reactivity, and cingulum GFA was observed in which men demonstrated a positive relationship while women demonstrated a negative relationship between GFA and cortisol reactivity. Finally, trait anxiety was positively associated with the GFA of the fornix/stria terminalis - the white matter pathways that connect the hippocampus/amygdala to the hypothalamus. These findings advance our understanding of factors that underlie individual differences in stress reactivity.

Therapeutic implications of hypothalamic-pituitaryadrenal-axis modulation in Alzheimer's disease: A narrative review of pharmacological and lifestyle interventions

With disease-modifying treatments for Alzheimer's disease (AD) still elusive, the search for alternative intervention strategies has intensified. Growing evidence suggests that dysfunction in hypothalamic-pituitaryadrenal-axis (HPAA) activity may contribute to the development of AD pathology. The HPAA, may therefore offer a novel target for therapeutic action. This review summarises and critically evaluates animal and human studies investigating the effects of pharmacological and non-pharmacological intervention on HPAA modulation alongside cognitive performance. The interventions discussed include glucocorticoid receptor antagonists and 11β-hydroxysteroid dehydrogenase inhibitors as well as lifestyle treatments such as physical activity, diet, sleep and contemplative practices. Pharmacological HPAA modulators improve pathology and cognitive deficit in animal AD models, but human pharmacological trials are yet to provide definitive support for such benefits. Lifestyle interventions may offer promising strategies for HPAA modification and cognitive health, but several methodological caveats across these studies were identified. Directions for future research in AD studies are proposed.

Promoting Successful Cognitive Aging: A Ten-Year Update

A decade has passed since we published a comprehensive review in this journal addressing the topic of promoting successful cognitive aging, making this a good time to take stock of the field. Because there have been limited large-scale, randomized controlled trials, especially following individuals from middle age to late life, some experts have questioned whether recommendations can be legitimately offered about reducing the risk of cognitive decline and dementia. Despite uncertainties, clinicians often need to at least make provisional recommendations to patients based on the highest quality data available. Converging lines of evidence from epidemiological/cohort studies, animal/basic science studies, human proof-of-concept studies, and human intervention studies can provide guidance, highlighting strategies for enhancing cognitive reserve and preventing loss of cognitive capacity. Many of the suggestions made in 2010 have been supported by additional research. Importantly, there is a growing consensus among major health organizations about recommendations to mitigate cognitive decline and promote healthy cognitive aging. Regular physical activity and treatment of cardiovascular risk factors have been supported by all of these organizations. Most organizations have also embraced cognitively stimulating activities, a heart-healthy diet, smoking cessation, and countering metabolic syndrome. Other behaviors like regular social engagement, limiting alcohol use, stress management, getting adequate sleep, avoiding anticholinergic medications, addressing sensory deficits, and protecting the brain against physical and toxic damage also have been endorsed, although less consistently. In this update, we review the evidence for each of these recommendations and offer practical advice about behavior-change techniques to help patients adopt brain-healthy behaviors.

Mesenchymal Stem Cell Transplantation for the Treatment of Cognitive Frailty

As life expectancy increases, frailty and cognitive impairment have become major factors influencing healthy aging in elderly individuals. Frailty is a complicated clinical condition characterized by decreased physiological reserve and multisystem abnormalities. Cognitive frailty is a subtype of frailty that has aroused widespread concern among the scientific community and public health organizations. We herein review the pathogenesis of cognitive frailty, such as chronic inflammatory response, immunological hypofunction, imbalanced oxidative stress, reduced regenerative function, endocrine dysfunction, and energy metabolism disorder. Although existing interventions show some therapeutic effects, they do not meet the current clinical needs. To date, studies using stem cell technology for treating age-related diseases have achieved remarkable success. This suggests the possibility of applying stem cell treatment to cognitive frailty. We analyzed stem cell-based strategies for targeting anti-inflammation, antioxidation, regeneration, and immunoregulation using mesenchymal stem cells, as well as potential therapeutic targets for cognitive frailty. Based on this investigation, we propose a highly effective and low-cost stem cell-based replacement strategy. However, there is a lack of comprehensive research on the prospect of stem cell transplantation for improving cognitive frailty. In this review, we aim to provide the scientific background and a theoretical basis for testing cell therapy in future research.

Prediction of salivary cortisol level by electroencephalography features

Change in cortisol affects brain EEG signals. So, the identification of the significant EEG features which are sensitized to cortisol concentration was the aim of the present study. From 468 participated healthy subjects, the salivary samples were taken to test the cortisol concentration and EEG signal recording was done simultaneously. Then, the subjects were categorized into three classes based on the salivary cortisol concentration (<5, 5-15 and >15 nmol/l). Some linear and nonlinear features extracted and finally, in order to investigate the relationship between cortisol level and EEG features, the following steps were taken on features in sequence: Genetic Algorithm, Neighboring Component Analysis, polyfit, artificial neural network and support vector machine classification. Two classifications were considered as following: state 1 categorized the subjects into three groups (three classes) and the second state put them into two groups (group 1: class 1 and 3, group 2: class 2). The best classification was done using ANN in the second state with the accuracy=94.1% while it was 92.7% in the first state. EEG features carefully predicted the cortisol level. This result is applicable to design the intelligence brain computer machines to control stress and brain performance.

Psychophysiological Responses in People Living with Dementia after an Art Gallery Intervention: An Exploratory Study

The use of existing public spaces by people living with dementia, such as museums and art galleries, are becoming popular due to their ability to facilitate programs which promote social engagement and inclusion. However, few studies have investigated physiological outcomes of art gallery-based programs. Using a quasi-experimental design, the present study aimed to investigate the levels of salivary biomarkers of cortisol and interleukin-6, quality of life (QoL), depressive symptoms, cognition, and wellbeing, after attending the National Gallery of Australia (NGA) Art and Dementia program. Twenty-eight people living with dementia, each supported by a carer or family member, were recruited for a six-week program and were followed up at twelve weeks. In total, 25 participants (17 female; mean age 84.6±7.27 years) completed the study, and 22 provided viable saliva samples. The waking to evening salivary cortisol ratio was higher post-intervention (p = 0.033), and returned to baseline levels at follow-up (p = 1.00), indicating a more dynamic salivary cortisol rhythm in response to the six-week program. Interleukin-6 levels remained unchanged (p = 0.664). No improvements in QoL (DEMQOL-Carer) were observed between baseline and post-intervention (p = 0.076). However, self-reported depressive symptoms decreased post-intervention compared with baseline (p = 0.015), and memory (immediate recall) (p = 0.009) and verbal fluency (p = 0.027) improved between the same timepoints. The NGA Art and Dementia program appears to have quantifiable benefits, including improved hypothalamic-pituitary-adrenal axis function, justifying a need for longer controlled trial inclusive of physiological outcomes.

Oral dysfunctions and cognitive impairment/dementia

With global increases in the aging population, the number of patients with dementia is greatly increasing, which has become a big social problem. Many studies have shown strong associations between oral disorders and systemic disorders, such as diabetes, arthritis, sepsis, aspiration pneumonia, arteriosclerosis, bacterial endocarditis, and other cardiovascular diseases. Similarly, numerous cross-sectional studies showed that patients with dementia usually have poor oral conditions and tooth loss. These have long been considered as a result of difficulty with oral care due to impaired cognitive function, memory, and physical ability in patients with dementia. Indeed, even in patients with mild cognitive impairment, oral care becomes insufficient owing to decreases in spontaneity of grooming and finger dexterity. However, recent studies have shown that tooth loss and occlusal dysfunction may affect brain function and trigger the onset of dementia found in neurodegenerative diseases including Alzheimer's disease. In this review, we highlight the relationships among aging, oral dysfunction, and the development of dementia. Increasing evidence suggests that oral dysfunction is not only a result of dementia in the elderly people, but could also be a causative factor for the onset of dementia.

Suggestibility and confabulation among individuals with Fetal Alcohol Spectrum Disorder: A review for criminal justice, forensic mental health, and legal interviewers

Fetal Alcohol Spectrum Disorders (FASD) are conditions arising from prenatal alcohol exposure which results in a range of neurodevelopmental deficits in areas including cognition, memory, language, executive functioning, emotional regulation, and adaptive functioning. Deficits in various neurodevelopmental areas can range from mild to severe, depending on many factors including the quantity and timing of alcohol exposure during the prenatal development period. During interviews in criminal justice, forensic mental health, and legal contexts (e.g., criminal investigations, cross examination, victim interviews, interviews for lawsuits, forensic evaluations, pre-sentence investigations), deficits associated with FASD may elevate the risk of suggestibility and confabulation. These issues can result in negative jurisprudence-related outcomes, including impulsive Miranda rights waivers, incorrect assumptions of competency, inaccurate or incomplete information gathering, misinterpretation of intent, witness reliability issues, court ordered treatment completion problems, probation and parole violations, false confessions, and false accusations. The aim of the present article is to explain the context in which these issues can arise and provide criminal justice, forensic mental health, and legal professionals with key guidelines that can assist in minimizing suggestibility and confabulation when interviewing persons with FASD. We hope that the suggestions and strategies presented in this article will reduce potential obstructions of justice and enhance the quality of information obtained from individuals impacted by FASD. A brief discussion is also provided to identify additional research and training opportunities needed to clarify "best practices" for professionals tasked with evaluating the challenges facing this unique population.

Crosstalk of gut microbiota and serum/hippocampus metabolites in neurobehavioral impairments induced by zinc oxide nanoparticles

The gut microbiome can be readily influenced by external factors, such as nanomaterials. However, the role of the microbiota-gut-brain axis in nanomaterials-induced neurotoxicity remains largely unknown. In this study, young mice aged 4 weeks were treated with either a vehicle solution or 26 mg kg-1 zinc oxide nanoparticles (ZnONPs) by intragastric administration for 30 days. The neurobehavioral alterations were assessed by the Morris water maze and open field test. Gut microbiota and the metabolites in both blood and hippocampus were detected using 16S rRNA sequencing and liquid chromatography-mass spectrometry metabolomics, respectively. The results demonstrated that oral exposure to ZnONPs resulted in neurobehavioral impairments in young mice, mainly manifested by spatial learning and memory deficits, and the inhibition of locomotor activity. Intriguingly, ZnONPs caused a marked disturbance of the gut microbial composition, but did not alter the α-diversity of the microbiota. The correlation analysis further revealed that neurobehavioral impairments induced by ZnONPs were closely associated with a perturbation in the gut microbiota composition that were specific to changes of neurobehavior-related genes (such as Bdnf and Dlg4), and correlated with serum and hippocampal metabolites. We also identified a unique metabolite [DG(15:0/0:0/22:4n6)] that linked relationships among the gut microbiota, metabolites and neurobehavior-related genes. Taken together, our results illustrated that oral exposure to ZnONPs not only altered the gut microbiome community, but also substantially disturbed the metabolic profiles leading to neurobehavioral impairments via the microbiota-gut-brain axis. These findings will provide a novel view for understanding the neurotoxicity of ZnONPs, and are helpful for identifying potential prevention and treatment strategies.

Exercise-Induced Elevated BDNF Level Does Not Prevent Cognitive Impairment Due to Acute Exposure to Moderate Hypoxia in Well-Trained Athletes

Exposure to acute hypoxia causes a detrimental effect on the brain which is also manifested by a decrease in the ability to perform psychomotor tasks. Conversely, brain-derived neurotrophic factor (BDNF), whose levels are elevated in response to exercise, is a well-known factor in improving cognitive function. Therefore, the aim of our study was to investigate whether the exercise under hypoxic conditions affects psychomotor performance. For this purpose, 11 healthy young athletes performed a graded cycloergometer exercise test to volitional exhaustion under normoxia and acute mild hypoxia (FiO₂ = 14.7%). Before, immediately after exercise and after a period of recovery, choice reaction time (CRT) and number of correct reactions (NCR) in relation to changes in serum BDNF were examined. Additionally, other selected factors which may modify BDNF production, i.e., cortisol (C), nitrite, catecholamines (adrenalin-A, noradrenaline-NA, dopamine-DA, serotonin-5-HT) and endothelin-1 (ET-1), were also measured. Exercise in hypoxic conditions extended CRT by 13.8% (p < 0.01) and decreased NCR (by 11.5%) compared to rest (p < 0.05). During maximal workload, NCR was lower by 9% in hypoxia compared to normoxia (p < 0.05). BDNF increased immediately after exercise in normoxia (by 29.3%; p < 0.01), as well as in hypoxia (by 50.0%; p < 0.001). There were no differences in BDNF between normoxia and hypoxia. Considering the fact that similar levels of BDNF were seen in both conditions but cognitive performance was suppressed in hypoxia, acute elevation of BDNF did not compensate for hypoxia-induced cognition impairment. Moreover, neither potentially negative effects of C nor positive effects of A, DA and NO on the brain were observed in our study.

Does Visual Speed of Processing Training Improve Health-Related Quality of Life in Assisted and Independent Living Communities?: A Randomized Controlled Trial

BACKGROUND AND OBJECTIVES

Visual speed of processing training had clinically and statistically significant beneficial effects on health-related quality of life among 2,802 healthy community-dwelling adults aged 65-94 years at 2 and 5 years post-training in the Advanced Cognitive Training for Independent and Vital Elderly randomized controlled trial. We examined whether that effect would be found among older adults in assisted and independent living communities.

RESEARCH DESIGN AND METHODS

We conducted a two-arm, parallel randomized controlled trial stratified by assisted versus independent settings in 31 senior living communities and enrolled 351 adults aged 55-102 years. The targeted intervention dose was 10 hr at baseline with 4-hr boosters at 5 and 11 months. The intervention group received computerized visual speed of processing training, while the attention control group solved computerized crossword puzzles. The health-related quality of life outcomes were the Short-Form 36-item Health Survey's mental and physical component T scores. Linear mixed-effect models were used.

RESULTS

Visual speed of processing, assisted living, and their interaction had no clinically or statistically significant effects on the physical component T scores. However, visual speed of processing (p = .022), assisted living (p = .022), and their interaction (p = .007) had clinically and statistically significant effects on the mental component T scores. The estimated marginal means revealed a small effect-sized positive 2.2 point visual speed of processing training effect in the independent living communities, but a clinically important harmful -4.2 point visual speed of processing training effect in the assisted living communities.

DISCUSSION AND IMPLICATIONS

Given the medium-sized harmful effect of visual speed of processing training among those in the assisted living communities, caution is advised when using these two visual speed of processing training modalities in assisted living communities until further research verifies or refutes our findings and the underlying etiological pathways.

Hydrolyzed Chicken Extract (ProBeptigen®) on Cognitive Function in Healthy Middle-Aged People: A Randomized Double-Blind Trial

Cognitive decline is an important issue of global public health. Cognitive aging might begin at middle adulthood, the period particularly vulnerable to stress in lifespan. Essence of chicken (EOC) has consistently demonstrated its beneficial effects on various cognitive domains as nutritional supplementation. This study primarily aimed to examine the cognitive enhancement effects of ProBeptigen^® (previously named CMI-168), hydrolyzed peptides extracted from EOC, in healthy middle-aged people under mild stress. Ninety healthy subjects were randomly assigned into the ProBeptigen^® or placebo group for eight weeks. Neurocognitive assessment, event-related potentials (ERPs), and blood tests were conducted before, during, and after the treatment. The ProBeptigen^® group outperformed placebo group on Logical Memory subtests of Wechsler Memory Scale-third edition (WMS-III) and Spatial Working Memory task in the Cambridge Neuropsychological Test Automated Battery (CANTAB). The anti-inflammatory effects of ProBeptigen^® in humans were also confirmed, with progressively declining high-sensitivity C-reactive protein (hs-CRP) levels. Regular dietary supplementation of ProBeptigen^® is suggested to improve verbal short- and long-term memory as well as spatial working memory, and reduce inflammation in middle-aged healthy individuals with stress. The effects of ProBeptigen^® on cognition warrant further investigation. (NCT03612752)

Food Insecurity and Cognitive Function in Middle to Older Adulthood: A Systematic Review

Food insecurity (FI) may limit cognitive functioning during aging. The goal of this systematic review was to summarize existing evidence linking FI and general or specific cognitive functions in middle and older adulthood. A systematic search of human studies published between 1 January 2000 and 30 April 2018 was conducted in PubMed, PsycINFO, and CAB Direct. Four independent reviewers assessed the eligibility of identified articles and conducted data extraction and data quality assessment. Ten studies were included in the review, including 1 cluster-randomized controlled trial, 2 longitudinal studies, and 7 cross-sectional studies. Three studies reported the association between early-life FI experience and a global cognitive function measure. Nine studies reported later-life FI experience in relation to global or specific cognitive functions. The results suggest an adverse association between FI experienced in early or later life and global cognitive function; and between later-life FI and executive function and memory. Findings from the review are preliminary because of sparse data, heterogeneity across study populations, exposure and outcome assessments, and potential risk of bias across studies. Future studies are recommended to better understand the role of FI in cognitive function, with the goal of identifying possible critical windows for correction of FI in vulnerable subpopulations to prevent neurocognitive deficit in adulthood.

Understanding the Physiological Links Between Physical Frailty and Cognitive Decline

Declines in both physical and cognitive function are associated with increasing age. Understanding the physiological link between physical frailty and cognitive decline may allow us to develop interventions that prevent and treat both conditions. Although there is significant epidemiological evidence linking physical frailty to cognitive decline, a complete understanding of the underpinning biological basis of the two disorders remains fragmented. This narrative review discusses insights into the potential roles of chronic inflammation, impaired hypothalamic-pituitary axis stress response, imbalanced energy metabolism, mitochondrial dysfunction, oxidative stress, and neuroendocrine dysfunction linking physical frailty with cognitive decline. We highlight the importance of easier identification of strategic approaches delaying the progression and onset of physical frailty and cognitive decline as well as preventing disability in the older population.

Sex and Gender Driven Modifiers of Alzheimer's: The Role for Estrogenic Control Across Age, Race, Medical, and Lifestyle Risks

Research indicates that after advanced age, the major risk factor for late-onset Alzheimer’s disease (AD) is female sex. Out of every three AD patients, two are females with postmenopausal women contributing to over 60% of all those affected. Sex- and gender-related differences in AD have been widely researched and several emerging lines of evidence point to different vulnerabilities that contribute to dementia risk. Among those being considered, it is becoming widely accepted that gonadal steroids contribute to the gender disparity in AD, as evidenced by the “estrogen hypothesis.” This posits that sex hormones, 17β-estradiol in particular, exert a neuroprotective effect by shielding females’ brains from disease development. This theory is further supported by recent findings that the onset of menopause is associated with the emergence of AD-related brain changes in women in contrast to men of the same age. In this review, we discuss genetic, medical, societal, and lifestyle risk factors known to increase AD risk differently between the genders, with a focus on the role of hormonal changes, particularly declines in 17β-estradiol during the menopause transition (MT) as key underlying mechanisms.

Pharmacological signatures of the reduced incidence and the progression of cognitive decline in ageing populations suggest the protective role of beneficial polypharmacy

Preventive treatments for dementia are warranted. Here we show that utilization of certain combinations of prescription medications and supplements correlates with reduced rates of cognitive decline. More than 1,900 FDA-approved agents and supplements were collapsed into 53 mechanism-based groups and traced in electronic medical records (EMRs) for >50,000 patients. These mechanistic groups were aligned with the data presented in more than 300 clinical trials, then regression model was built to fit the signals from EMRs to clinical trial performance. While EMR signals of each single agents correlated with clinical performance relatively weakly, the signals produced by combinations of active compounds were highly correlated with the clinical trial performance (R = 0.93, p = 3.8 x10^-8). Higher ranking pharmacological modalities were traced in patient profiles as their combinations, producing protective complexity estimates reflecting degrees of exposure to beneficial polypharmacy. For each age strata, the higher was the protective complexity score, the lower was the prevalence of dementia, with maximized life-long effects for the highest regression score /diversity compositions. The connection was less strong in individuals already diagnosed with cognitive impairment. Confounder analysis confirmed an independent effect of protective complexity in multivariate context. A sub-cohort with lifelong odds of dementia decreased > 5-folds was identified; this sub-cohort should be studied in further details, including controlled clinical trials. In short, our study systematically explored combinatorial preventive treatment regimens for age-associated multi-morbidity, with an emphasis on neurodegeneration, and provided extensive evidence for their feasibility.

Circulating IGFBP-2: a novel biomarker for incident dementia

OBJECTIVE

To determine the association between plasma insulin-like growth factor binding protein 2 (IGFBP-2) and cognitive outcomes.

METHODS

We measured plasma IGFBP-2 levels in 1596 (53% women, mean age 68.7 [SD 5.7] years) dementia-free Framingham Offspring cohort participants between 1998 and 2001. Multivariable Cox proportional hazards models related plasma IGFBP-2 to subsequent risk of incident dementia and Alzheimer's disease. MRI brain measures and cognitive performance were included as secondary outcomes.

RESULTS

During a median follow-up of 11.8 (Q1, Q3: 7.1, 13.3) years, 131 participants developed incident dementia, of whom 98 were diagnosed with Alzheimer's disease. The highest tertile of IGFBP-2, compared to the lowest tertile, was associated with an increased risk of incident all-cause dementia (hazard ratio [HR] 2.89, 95% CI 1.63-5.13) and Alzheimer's disease (HR 3.63, 95% CI 1.76-7.50) in multivariable analysis. Higher circulating IGFBP2 levels were also cross-sectionally associated with poorer performance on tests of abstract reasoning but not with MRI-based outcomes. After adding plasma IGFBP-2 levels to a conventional dementia prediction model, 32% of individuals with dementia were correctly assigned a higher predicted risk, while 8% of individuals without dementia were correctly assigned a lower predicted risk (overall net reclassification improvement index, 0.40, 95% CI 0.22-0.59).

INTERPRETATION

Elevated circulating IGFBP-2 levels were associated with an increased risk of both all-cause dementia and Alzheimer's disease. Addition of IGFBP2 plasma levels to a model of traditional risk factors significantly improved dementia risk classification. Manipulation of insulin-like growth factor signaling via IGFBP-2 may be a promising therapeutic target for dementia.

An anti-CRF antibody suppresses the HPA axis and reverses stress-induced phenotypes

A high-affinity monoclonal antibody (CTRND05) targeting corticotropin-releasing factor (CRF) blocks stress-induced corticosterone increases, counteracts effects of chronic variable stress, and induces other phenotypes consistent with suppression of the HPA axis.

Hypothalamic–pituitary–adrenal (HPA) axis dysfunction contributes to numerous human diseases and disorders. We developed a high-affinity monoclonal antibody, CTRND05, targeting corticotropin-releasing factor (CRF). In mice, CTRND05 blocks stress-induced corticosterone increases, counteracts effects of chronic variable stress, and induces other phenotypes consistent with suppression of the HPA axis. CTRND05 induces skeletal muscle hypertrophy and increases lean body mass, effects not previously reported with small-molecule HPA-targeting pharmacologic agents. Multiorgan transcriptomics demonstrates broad HPA axis target engagement through altering levels of known HPA-responsive transcripts such as Fkbp5 and Myostatin and reveals novel HPA-responsive pathways such as the Apelin-Apelin receptor system. These studies demonstrate the therapeutic potential of CTRND05 as a suppressor of the HPA axis and serve as an exemplar of a potentially broader approach to target neuropeptides with immunotherapies, as both pharmacologic tools and novel therapeutics.

Age-Accelerated Reduction in Cortical Surface Area in United States Service Members and Veterans with Mild Traumatic Brain Injury and Post-Traumatic Stress Disorder

Despite the prevalence of combat-related mild traumatic brain injury (mTBI) and relatively high incidence of concurrent post-traumatic stress disorder (PTSD), the joint effect of these conditions on the brain is not well understood. Further, few studies in the mTBI or PTSD populations focus on cortical surface area measures, despite known disruptions to cytoarchitecture of the cortex. This study examines the effects of comorbid mTBI and PTSD on age-related surface area changes across the cortex, as compared with a group with mTBI only. While a direct comparison of PTSD versus non-PTSD groups showed little difference on surface area measures, several regions showed a decline in surface area, with increasing age and a significant PTSD-by-age interaction effect, indicating an age-dependent decrease in surface area in those with both mTBI and PTSD. The findings suggest an apparent age-accelerated shrinking of the cortical surface area in some regions when mTBI and PTSD are present, a pattern that was not consistently found in those with mTBI only. Among the several cortical regions with significant age-by-group interactions were bilateral posterior cingulate cortex (left: p = 0.03; right: p = 0.02), isthmus of the cingulate (left: p = 0.016; right: p = 0.001), and lateral orbitofrontal cortex (left: p = 0.038; right: p = 0.02). It is possible that these findings are related to a larger pattern of premature neurodegeneration and age-acceleration noted in those with long-term PTSD.

High Cortisol and the Risk of Dementia and Alzheimer's Disease: A Review of the Literature

Introduction: Cortisol effects on the brain are exerted through two distinct receptors, inducing complex and even opposite effects on the cerebral structures implicated in the various cognitive functions. High cortisol may also have deleterious effects on the brain structures and contribute to neurodegeneration, in particular Alzheimer’s disease (AD), via different mechanisms.

Objective: To examine the interrelationships between cortisol, cognitive impairment and AD.

Methods: Review of the literature.

Results: Clinical studies found that elevated cortisol was associated with poorer overall cognitive functioning, as well as with poorer episodic memory, executive functioning, language, spatial memory, processing speed, and social cognition; while in animals, glucocorticoid administration resulted in cognitive impairment and abnormal behavior. In cognitively healthy subjects, higher cortisol levels have been associated with an increased risk of cognitive decline and AD. Subjects with dementia and Mild Cognitive Impairment (MCI) due to AD have been found to have higher CSF cortisol levels than cognitively healthy controls. Elevated CSF cortisol may also be associated with a more rapid cognitive decline in MCI due to AD. Elevated cortisol levels have been also found in delirium. High cortisol may mediate the impact of stressful life events, high neuroticism, depression, sleep disturbances, as well as cardiovascular risk factors on cognitive performance, neurodegeneration, and cognitive decline. High cortisol may also exert neurotoxic effects on the hippocampus, and promote oxidative stress and amyloid β peptide toxicity. Further possible underlying mechanisms include the interactions of cortisol with inflammatory mediators, neurotransmitters, and growth factors.

Conclusion: Elevated cortisol levels may exert detrimental effects on cognition and contribute to AD pathology. Further studies are needed to investigate cortisol-reducing and glucocorticoidreceptor modulating interventions to prevent cognitive decline.