Bridging animal and human models of exercise-induced brain plasticity

Stress-Related Dysfunction of Adult Hippocampal Neurogenesis-An Attempt for Understanding Resilience?

Newborn neurons in the adult hippocampus are regulated by many intrinsic and extrinsic cues. It is well accepted that elevated glucocorticoid levels lead to downregulation of adult neurogenesis, which this review discusses as one reason why psychiatric diseases, such as major depression, develop after long-term stress exposure. In reverse, adult neurogenesis has been suggested to protect against stress-induced major depression, and hence, could serve as a resilience mechanism. In this review, we will summarize current knowledge about the functional relation of adult neurogenesis and stress in health and disease. A special focus will lie on the mechanisms underlying the cascades of events from prolonged high glucocorticoid concentrations to reduced numbers of newborn neurons. In addition to neurotransmitter and neurotrophic factor dysregulation, these mechanisms include immunomodulatory pathways, as well as microbiota changes influencing the gut-brain axis. Finally, we discuss recent findings delineating the role of adult neurogenesis in stress resilience.

Training Executive, Attention, and Motor Skills (TEAMS): a Preliminary Randomized Clinical Trial of Preschool Youth with ADHD

This preliminary randomized controlled trial compared Training Executive, Attention and Motor Skills (TEAMS), a played-based intervention for preschool children with attention-deficit/hyperactivity disorder (ADHD), to an active comparison intervention consisting of parent education and support (ClinicalTrials.gov Identifier: NCT01462032). The primary aims were to gauge preliminary efficacy and assist in further development of TEAMS. Four- and 5-year-old children with ADHD were randomly assigned to receive TEAMS (N = 26) or the comparison intervention (N = 26) with blinded assessments by parents, teachers and clinicians ascertained pretreatment, post-treatment, and 1- and 3-months post-treatment. Changes in ADHD severity, impairment, parenting factors, and neuropsychological functioning over time as a function of treatment condition were assessed using the PROC MIXED procedure in SAS. Across most measures, significant main effects for Time emerged; both treatments were associated with reduced ADHD symptoms that persisted for three months post-treatment. There were no significant Treatment effects or Time x Treatment interactions on symptom and impairment measures, suggesting that the magnitude of improvement did not differ between the two interventions. However, significant correlations emerged between the magnitude of behavioral change, as assessed by parents and clinicians, and the amount of time families engaged in TEAMS-related activities during treatment. Across a wide array of parenting and neuropsychological measures, there were few significant group differences over time. TEAMS and other psychosocial interventions appear to provide similar levels of benefit. Play-based interventions like TEAMS represent a potentially viable alternative/addition to current ADHD treatments, particularly for young children, but more research and further development of techniques are necessary.

Cannabis Use and Brain Volume in Adolescent and Young Adult Cannabis Users: Effects Moderated by Sex and Aerobic Fitness

OBJECTIVES

Studies examining the impact of adolescent and young adult cannabis use on structural outcomes have been heterogeneous. One already-identified moderator is sex, while a novel potential moderator is extent of aerobic fitness. Here, we sought to investigate the associations of cannabis use, sex, and aerobic fitness levels on brain volume. Second, we explored brain-behavior relationships to interpret these findings.

METHODS

Seventy-four adolescents and young adults (36 cannabis users and 38 controls) underwent 3 weeks of monitored cannabis abstinence, aerobic fitness testing, structural neuroimaging, and neuropsychological testing. Linear regressions examined cannabis use and its interaction with sex and aerobic fitness on whole-brain cortical volume and subcortical regions of interests.

RESULTS

No main-effect differences between cannabis users and nonusers were observed; however, cannabis-by-sex interactions identified differences in frontal, temporal, and paracentral volumes. Female cannabis users generally exhibited greater volume while male users exhibited less volume compared to same-sex controls. Positive associations between aerobic fitness and frontal, parietal, cerebellum, and caudate volumes were observed. Cannabis-by-fitness interaction was linked with left superior temporal volume. Preliminary brain-behavior correlations revealed that abnormal volumes were not advantageous in either male or female cannabis users.

CONCLUSIONS

Aerobic fitness was linked with greater brain volume and sex moderated the effect of cannabis use on volume; preliminary brain-behavior correlations revealed that differences in cannabis users were not linked with advantageous cognitive performance. Implications of sex-specific subtleties and mechanisms of aerobic fitness require large-scale investigation. Furthermore, present findings and prior literature on aerobic exercise warrant examinations of aerobic fitness interventions that aimed at improving neurocognitive health in substance-using youth.

Association of Lifestyle Activities with Functional Brain Connectivity and Relationship to Cognitive Decline among Older Adults

This study examines the relationship of engagement in different lifestyle activities to connectivity in large-scale functional brain networks, and whether network connectivity modifies cognitive decline, independent of brain amyloid levels. Participants (N = 153, mean age = 69 years, including N = 126 with amyloid imaging) were cognitively normal when they completed resting-state functional magnetic resonance imaging, a lifestyle activity questionnaire, and cognitive testing. They were followed with annual cognitive tests up to 5 years (mean = 3.3 years). Linear regressions showed positive relationships between cognitive activity engagement and connectivity within the dorsal attention network, and between physical activity levels and connectivity within the default-mode, limbic, and frontoparietal control networks, and global within-network connectivity. Additionally, higher cognitive and physical activity levels were independently associated with higher network modularity, a measure of functional network specialization. These associations were largely independent of APOE4 genotype, amyloid burden, global brain atrophy, vascular risk, and level of cognitive reserve. Moreover, higher connectivity in the dorsal attention, default-mode, and limbic networks, and greater global connectivity and modularity were associated with reduced cognitive decline, independent of APOE4 genotype and amyloid burden. These findings suggest that changes in functional brain connectivity may be one mechanism by which lifestyle activity engagement reduces cognitive decline.

Physical Fitness Plays a Crucial Mediator Role in Relationships Among Personal, Social, and Lifestyle Factors With Adolescents' Cognitive Performance in a Structural Equation Model. The Cogni-Action Project

Background: The beneficial relationship between physical fitness and cognitive performance is affected and modulated by a wide diversity of factors that seem to be more sensitive during the development stage, particularly during early adolescence. This study aimed to examine the role of physical fitness considering the multivariate association between age, health-related quality of life (HRQOL), school vulnerability index (SVI), body mass index z-score (BMIz), physical activity, and sleep problems with the cognitive performance in boys and girls. Method: Participants were 1,196 adolescents aged 10-14 years (50.7% of boys) from Chile. Three physical fitness components and eight cognitive tasks were measured. BMIz was determined using growth references by age and sex, whereas questionaries were used to assess sleep problems, physical activity, and HRQOL. SVI was established according to the score given by the Chilean Government to educational establishments. We performed a structural equation model (SEM) to test multivariate associations among study' variables by sex. Results: Fitness was positively associated with boys' and girls' cognitive performance (β = 0.23 and β = 0.17; p = 0.001, respectively). Moreover, fitness presented a significant mediator role in the relationships between BMIz, SVI, and physical activity with cognitive performance (indirect effect). Additionally, SVI showed a negative association both direct and indirect effect in all three fitness components and all cognitive tasks, being this relationship stronger in girls than in boys. Conclusion: Our findings suggest that physical fitness and all its components play a crucial mediator role in the associations between several factors associated with adolescents' cognitive performance. Thereby, educational and health strategies should prioritise improving physical fitness through physical activity. They also should address other factors such as school vulnerability, obesity, and the early gender gap in a comprehensive approach boosting cognitive performance among early adolescents. Trial registration: Research Registry (ID: researchregistry5791).

Proteasome stress in skeletal muscle mounts a long-range protective response that delays retinal and brain aging

Neurodegeneration in the central nervous system (CNS) is a defining feature of organismal aging that is influenced by peripheral tissues. Clinical observations indicate that skeletal muscle influences CNS aging, but the underlying muscle-to-brain signaling remains unexplored. In Drosophila, we find that moderate perturbation of the proteasome in skeletal muscle induces compensatory preservation of CNS proteostasis during aging. Such long-range stress signaling depends on muscle-secreted Amyrel amylase. Mimicking stress-induced Amyrel upregulation in muscle reduces age-related accumulation of poly-ubiquitinated proteins in the brain and retina via chaperones. Preservation of proteostasis stems from the disaccharide maltose, which is produced via Amyrel amylase activity. Correspondingly, RNAi for SLC45 maltose transporters reduces expression of Amyrel-induced chaperones and worsens brain proteostasis during aging. Moreover, maltose preserves proteostasis and neuronal activity in human brain organoids challenged by thermal stress. Thus, proteasome stress in skeletal muscle hinders retinal and brain aging by mounting an adaptive response via amylase/maltose.

Aerobic Exercise Induces Alternative Splicing of Neurexins in Frontal Cortex

Aerobic exercise (AE) is known to produce beneficial effects on brain health by improving plasticity, connectivity, and cognitive functions, but the underlying molecular mechanisms are still limited. Neurexins (Nrxns) are a family of presynaptic cell adhesion molecules that are important in synapsis formation and maturation. In vertebrates, three-neurexin genes (NRXN1, NRXN2, and NRXN3) have been identified, each encoding for α and β neurexins, from two independent promoters. Moreover, each Nrxns gene (1-3) has several alternative exons and produces many splice variants that bind to a large variety of postsynaptic ligands, playing a role in trans-synaptic specification, strength, and plasticity. In this study, we investigated the impact of a continuous progressive (CP) AE program on alternative splicing (AS) of Nrxns on two brain regions: frontal cortex (FC) and hippocampus. We showed that exercise promoted Nrxns1-3 AS at splice site 4 (SS4) both in α and β isoforms, inducing a switch from exon-excluded isoforms (SS4-) to exon-included isoforms (SS4+) in FC but not in hippocampus. Additionally, we showed that the same AE program enhanced the expression level of other genes correlated with synaptic function and plasticity only in FC. Altogether, our findings demonstrated the positive effect of CP AE on FC in inducing molecular changes underlying synaptic plasticity and suggested that FC is possibly a more sensitive structure than hippocampus to show molecular changes.

Effects of Marathon Running on Cognition and Retinal Vascularization: A Longitudinal Observational Study

INTRODUCTION

Physical activity has beneficial effects on both cardiovascular and neurocognitive parameters, and these 2 modalities are known to interact at rest. However, findings on their interaction during exercise are inconclusive.

PURPOSE

Therefore, this longitudinal study aimed to investigate the effects of different forms of exercise (training period, marathon race, recovery period) on both parameters and their interaction.

METHODS

We included 100 marathon runners (MA) (mean [SD] age: 43.6 [10.0] years, 80 male) and 46 age- and sex-matched sedentary controls (SC, for baseline comparison). Over the 6-month study period with 6 visits (12 and 2 weeks before the marathon; immediately, 24 hours, 72 hours and 12 weeks after the marathon), we assessed cognitive parameters by evaluating 1-to 3-back d prime, the d2 task, and the Trail Making Test A (TMTA) and B (TMTB); retinal vessel parameters by assessing arteriolar-to-venular ratio (AVR), central retinal arteriolar and venular equivalents (CRAE/CRVE).

RESULTS

In the long-term analysis, 3-back d prime correlated positively with AVR (P = 0.024, B = 1.86,SE = 0.824) and negatively with CRVE (P = 0.05,B = -0.006,SE = 0.003) and TMTB correlated negatively with CRAE (P = 0.025,B = -0.155,SE = 0.069), even after correcting for age and systolic blood pressure as possible confounders. Acute effects were inconsistent with maximal cognitive improvement 24 hours after the marathon. AVR was significantly smaller in SC compared to MA.

CONCLUSION

Chronic exercise seems to prime the central nervous system for acute, intensive bouts of exercise. Our findings indicate a possible relationship between cognitive performance in high-demand tasks and retinal vasculature and support the idea of a neuroplastic effect of exercise.

Effects of Aerobic Exercise Training on Systemic Biomarkers and Cognition in Late Middle-Aged Adults at Risk for Alzheimer's Disease

Increasing evidence indicates that physical activity and exercise training may delay or prevent the onset of Alzheimer's disease (AD). However, systemic biomarkers that can measure exercise effects on brain function and that link to relevant metabolic responses are lacking. To begin to address this issue, we utilized blood samples of 23 asymptomatic late middle-aged adults, with familial and genetic risk for AD (mean age 65 years old, 50% female) who underwent 26 weeks of supervised treadmill training. Systemic biomarkers implicated in learning and memory, including the myokine Cathepsin B (CTSB), brain-derived neurotrophic factor (BDNF), and klotho, as well as metabolomics were evaluated. Here we show that aerobic exercise training increases plasma CTSB and that changes in CTSB, but not BDNF or klotho, correlate with cognitive performance. BDNF levels decreased with exercise training. Klotho levels were unchanged by training, but closely associated with change in VO2peak. Metabolomic analysis revealed increased levels of polyunsaturated free fatty acids (PUFAs), reductions in ceramides, sphingo- and phospholipids, as well as changes in gut microbiome metabolites and redox homeostasis, with exercise. Multiple metabolites (~30%) correlated with changes in BDNF, but not CSTB or klotho. The positive association between CTSB and cognition, and the modulation of lipid metabolites implicated in dementia, support the beneficial effects of exercise training on brain function. Overall, our analyses indicate metabolic regulation of exercise-induced plasma BDNF changes and provide evidence that CTSB is a marker of cognitive changes in late middle-aged adults at risk for dementia.

Neurocognitive Plasticity Is Associated with Cardiorespiratory Fitness Following Physical Exercise in Older Adults with Amnestic Mild Cognitive Impairment

BACKGROUND

Aerobic training has been shown to promote structural and functional neurocognitive plasticity in cognitively intact older adults. However, little is known about the neuroplastic potential of aerobic exercise in individuals at risk of Alzheimer's disease (AD) and dementia.

OBJECTIVE

We aimed to explore the effect of aerobic exercise intervention and cardiorespiratory fitness improvement on brain and cognitive functions in older adults with amnestic mild cognitive impairment (aMCI).

METHODS

27 participants with aMCI were randomized to either aerobic training (n = 13) or balance and toning (BAT) control group (n = 14) for a 16-week intervention. Pre- and post-assessments included functional MRI experiments of brain activation during associative memory encoding and neural synchronization during complex information processing, cognitive evaluation using neuropsychological tests, and cardiorespiratory fitness assessment.

RESULTS

The aerobic group demonstrated increased frontal activity during memory encoding and increased neural synchronization in higher-order cognitive regions such as the frontal cortex and temporo-parietal junction (TPJ) following the intervention. In contrast, the BAT control group demonstrated decreased brain activity during memory encoding, primarily in occipital, temporal, and parietal areas. Increases in cardiorespiratory fitness were associated with increases in brain activationin both the left inferior frontal and precentral gyri. Furthermore, changes in cardiorespiratory fitness were also correlated with changes in performance on several neuropsychological tests.

CONCLUSION

Aerobic exercise training may result in functional plasticity of high-order cognitive areas, especially, frontal regions, among older adults at risk of AD and dementia. Furthermore, cardiorespiratory fitness may be an important mediating factor of the observed changes in neurocognitive functions.

The aging brain: sleep, the circadian clock and exercise

Aging is a multifactorial process likely stemming from damage accumulation and/or a decline in maintenance and repair mechanisms in the organisms that eventually determine their lifespan. In our review, we focus on the morphological and functional alterations that the aging brain undergoes affecting sleep and the circadian clock in both human and rodent models. Although both species share mammalian features, differences have been identified on several experimental levels, which we outline in this review. Additionally, we delineate some challenges on the preferred analysis and we suggest that a uniform route is followed so that findings can be smoothly compared. We conclude by discussing potential interventions and highlight the influence of physical exercise as a beneficial lifestyle intervention, and its effect on healthy aging and longevity. We emphasize that even moderate age-matched exercise is able to ameliorate several aging characteristics as far as sleep and circadian rhythms are concerned, independent of the species studied.

Educational and Social Exergaming: A Perspective on Physical, Social, and Educational Benefits and Pitfalls of Exergaming at Home During the COVID-19 Pandemic and Afterwards

Physical inactivity and coronavirus disease 2019 (COVID-19) signify two pandemics with negative physical, mental, and economic consequences. Younger and older people have not reached the recommended physical activity level for years. Societal restrictions due to COVID-19 additionally reduce opportunities for physical activity, and they increase social isolation. Here, we outline how playing exergames with others (social exergaming) at home could foster physical and mental health and promote communication and discussions on exergaming. Accordingly, we highlight the educational and social benefits of exergaming at home and delineate the concept of Educational and Social Exergaming (EASE). We outline specific benefits and pitfalls of exergaming regarding its physical and nonphysical effects, including educational values of discussing exergaming experiences and related topics. Moreover, we discuss the relevance of practical guidelines for educational and social exergaming at home as well as prospects for future research. Overall, educational and social exergaming could alleviate several detrimental effects of both pandemics on the health and well-being of people of all ages.

Exercise Training-Related Changes in Cortical Gray Matter Diffusivity and Cognitive Function in Mild Cognitive Impairment and Healthy Older Adults

Individuals with Mild Cognitive Impairment (MCI) are at an elevated risk of dementia and exhibit deficits in cognition and cortical gray matter (GM) volume, thickness, and microstructure. Meanwhile, exercise training appears to preserve brain function and macrostructure may help delay or prevent the onset of dementia in individuals with MCI. Yet, our understanding of the neurophysiological effects of exercise training in individuals with MCI remains limited. Recent work suggests that the measures of gray matter microstructure using diffusion imaging may be sensitive to early cognitive and neurophysiological changes in the aging brain. Therefore, this study is aimed to determine the effects of exercise training in cognition and cortical gray matter microstructure in individuals with MCI vs. cognitively healthy older adults. Fifteen MCI participants and 17 cognitively intact controls (HC) volunteered for a 12-week supervised walking intervention. Following the intervention, MCI and HC saw improvements in cardiorespiratory fitness, performance on Trial 1 of the Rey Auditory Verbal Learning Test (RAVLT), a measure of verbal memory, and the Controlled Oral Word Association Test (COWAT), a measure of verbal fluency. After controlling for age, a voxel-wise analysis of cortical gray matter diffusivity showed individuals with MCI exhibited greater increases in mean diffusivity (MD) in the left insular cortex than HC. This increase in MD was positively associated with improvements in COWAT performance. Additionally, after controlling for age, the voxel-wise analysis indicated a main effect of Time with both groups experiencing an increase in left insular and left and right cerebellar MD. Increases in left insular diffusivity were similarly found to be positively associated with improvements in COWAT performance in both groups, while increases in cerebellar MD were related to gains in episodic memory performance. These findings suggest that exercise training may be related to improvements in neural circuits that govern verbal fluency performance in older adults through the microstructural remodeling of cortical gray matter. Furthermore, changes in left insular cortex microstructure may be particularly relevant to improvements in verbal fluency among individuals diagnosed with MCI.

Physical exercise improves quality of life, depressive symptoms, and cognition across chronic brain disorders: a transdiagnostic systematic review and meta-analysis of randomized controlled trials

We performed a meta-analysis to synthesize evidence on the efficacy and safety of physical exercise as an add-on therapeutic intervention for quality of life (QoL), depressive symptoms and cognition across six chronic brain disorders: Alzheimer's disease, Huntington's disease, multiple sclerosis, Parkinson's disease, schizophrenia and unipolar depression. 122 studies ( = k) (n = 7231) were included. Exercise was superior to treatment as usual in improving QoL (k = 64, n = 4334, ES = 0.40, p < 0.0001), depressive symptoms (k = 60, n = 2909, ES = 0.78, p < 0.0001), the cognitive domains attention and working memory (k = 21, n = 1313, ES = 0.24, p < 0.009), executive functioning (k = 14, n = 977, ES = 0.15, p = 0.013), memory (k = 12, n = 994, ES = 0.12, p = 0.038) and psychomotor speed (k = 16, n = 896, ES = 0.23, p = 0.003). Meta-regression showed a dose-response effect for exercise time (min/week) on depressive symptoms (β = 0.007, p = 0.012). 69% of the studies that reported on safety, found no complications. Exercise is an efficacious and safe add-on therapeutic intervention showing a medium-sized effect on QoL and a large effect on mood in patients with chronic brain disorders, with a positive dose-response correlation. Exercise also improved several cognitive domains with small but significant effects.

The effect of a one-year vigorous physical activity intervention on fitness, cognitive performance and mental health in young adolescents: the Fit to Study cluster randomised controlled trial

Background

Physical activity (PA) may positively stimulate the brain, cognition and mental health during adolescence, a period of dynamic neurobiological development. High-intensity interval training (HIIT) or vigorous PA interventions are time-efficient, scalable and can be easily implemented in existing school curricula, yet their effects on cognitive, academic and mental health outcomes are unclear. The primary aim of the Fit to Study trial was to investigate whether a pragmatic and scalable HIIT-style VPA intervention delivered during school physical education (PE) could improve attainment in maths. The primary outcome has previously been reported and was null. Here, we report the effect of the intervention on prespecified secondary outcomes, including cardiorespiratory fitness, cognitive performance, and mental health in young adolescents.

Methods

The Fit to Study cluster randomised controlled trial included Year 8 pupils (n = 18,261, aged 12–13) from 104 secondary state schools in South/Mid-England. Schools were randomised into an intervention condition (n = 52), in which PE teachers delivered an additional 10 min of VPA per PE lesson for one academic year (2017–2018), or into a “PE as usual” control condition. Secondary outcomes included assessments of cardiorespiratory fitness (20-m shuttle run), cognitive performance (executive functions, relational memory and processing speed) and mental health (Strength and Difficulties Questionnaire and self-esteem measures). The primary intention-to-treat (ITT) analysis used linear models and structural equation models with cluster-robust standard errors to test for intervention effects. A complier-average causal effect (CACE) was estimated using a two-stage least squares procedure.

Results

The HIIT-style VPA intervention did not significantly improve cardiorespiratory fitness, cognitive performance (executive functions, relational memory or processed speed), or mental health (all p > 0.05). Subgroup analyses showed no significant moderation of intervention effects by sex, socioeconomic status or baseline fitness levels. Changes in cardiorespiratory fitness were not significantly related to changes in cognitive or mental health outcomes. The trial was marked by high drop-out and low intervention compliance. Findings from the CACE analysis were in line with those from the ITT analysis.

Conclusion

The one-academic year HIIT-style VPA intervention delivered during regular school PE did not significantly improve fitness, cognitive performance or mental health, but these findings should be interpreted with caution given low implementation fidelity and high drop-out. Well-controlled, large-scale, school-based trials that examine the effectiveness of HIIT-style interventions to enhance cognitive and mental health outcomes are warranted.

Trial registration

ISRCTN registry, 15,730,512. Trial protocol and analysis plan for primary outcome prospectively registered on 30th March 2017.

ClinicalTrials.gov, NCT03286725. Secondary measures (focus of current manuscript) retrospectively registered on 18 September 2017.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12966-021-01113-y.

Differential Effects of Physical and Social Enriched Environment on Angiogenesis in Male Rats After Cerebral Ischemia/Reperfusion Injury

Different housing conditions, including housing space and the physiological and social environment, may affect rodent behavior. Here, we examined the effects of different housing conditions on post-stroke angiogenesis and functional recovery to clarify the ambiguity about environmental enrichment and its components. Male rats in the model groups underwent right middle cerebral artery occlusion (MCAO) followed by reperfusion. The MCAO rats were divided into four groups: the physical enrichment (PE) group, the social enrichment (SE) group, the combined physical and social enrichment (PSE) group and the ischemia/reperfusion + standard conditioning (IS) group. The rats in the sham surgery (SS) group were housed under standard conditions. In a set of behavioral tests, including the modified Neurological Severity Score (mNSS), rotarod test, and adhesive removal test, we demonstrated that the animals in the enriched condition groups exhibited significantly improved neurological functions compared to those in the standard housing group. Smaller infarction volumes were observed in the animals of the PSE group by MRI detection. The enriched conditions increased the microvessel density (MVD) in the ischemic boundary zone, as revealed by CD31 immunofluorescent staining. The immunochemical and q-PCR results further showed that environmental enrichment increased the expression levels of angiogenic factors after ischemia/reperfusion injury. Our data suggest that all three enrichment conditions promoted enhanced angiogenesis and functional recovery after ischemia/reperfusion injury compared to the standard housing, while only exposure to the combination of both physical and social enrichment yielded optimal benefits.

The Combined Effects of Obesity and Cardiorespiratory Fitness Are Associated with Response Inhibition: An ERP Study

Obesity and cardiorespiratory fitness exhibit negative and positive impacts, respectively, on executive function. Nevertheless, the combined effects of these two factors on executive function remain unclear. This study investigated the combined effects of obesity and cardiorespiratory fitness on response inhibition of executive function from both behavioral and neuroelectric perspectives. Ninety-six young adults aged between 18 and 25 years were recruited and assigned into four groups: the high cardiorespiratory fitness with normal weight (NH), high cardiorespiratory fitness with obesity (OH), low cardiorespiratory fitness with normal weight (NL), and low cardiorespiratory fitness with obesity (OL) groups. The stop-signal task and its induced P3 component of event-related potentials was utilized to index response inhibition. The participants with higher cardiorespiratory fitness (i.e., the NH and OH groups) demonstrated better behavioral performance (i.e., shorter response times and higher accuracy levels), as well as shorter stop-signal response times and larger P3 amplitudes than their counterparts with low cardiorespiratory fitness (i.e., the NL and OL groups). The study provides first-hand evidence of the substantial effects of cardiorespiratory fitness on the response inhibition, including evidence that the detrimental effects of obesity might be overcome by high cardiorespiratory fitness.

Physical activity and its association with cognitive function in middle- and older-aged Chinese: Evidence from China Health and Retirement Longitudinal Study, 2015

BACKGROUND

Despite the known benefits of physical activity (PA) on cognitive function, the specific dimensions of PA that are associated with cognitive function require further research in China. We aimed to explore the patterns of PA and elucidate the association between cognitive function and different levels of PA in middle aged and elderly Chinese individuals.

METHODS

A total of 8,023 participants aged ≥45 years were selected from the China Health and Retirement Longitudinal Study. The PA intensity was categorized as: vigorous (VPA), moderate (MPA), and light (LPA). The associations of frequency and duration of PA at different intensities with cognitive function were examined using the multivariable linear model, including all respondents and urban-rural subgroups.

RESULTS

Compared with those who had no VPA, those who spent 6-7 days/week (β = -0.59, 95% CI: -1.10, -0.09) or more than 240 min/each time on VPA had poorer cognitive function among rural respondents, whereas cognitive function was only associated with the duration in urban respondents. Compared with those who had no MPA, the rural respondents who spent 1-5 days/week (β = 0.66, 95% CI: 0.12, 1.20) or 6-7days/week, or spent < 2 hours each time had better cognitive function. For LPA, frequency and duration were both positively associated with cognitive function, and were observed in both rural and urban sub-groups.

CONCLUSIONS

The association between cognitive function and PA depended largely on the intensity and area. Cultural context and geographical differences should be considered when designing intervention policies.Highlights The prevalence of PA increased as the intensity decreased and was higher in rural respondents than in urban respondents.Cognitive function was related to the intensity, frequency, and duration of PA. However, the magnitude and direction of the association depended mainly on the intensity and geographical area.VPA was negatively correlated with cognitive function, and the association was significant only in rural respondents. However, MPA and LPA were positively correlated with cognitive function, while the association between LPA and cognitive function was significant in both rural and urban respondents.

Identifying animal complex cognition requires natural complexity

The search for human cognitive uniqueness often relied on low ecological tests with subjects experiencing unnatural ontogeny. Recently, neuroscience demonstrated the significance of a rich environment on the development of brain structures and cognitive abilities. This stresses the importance to consider the prior knowledge that subjects bring in any experiment. Second, recent developments in multivariate statistics control precisely for a number of factors and their interactions. Making controls in natural observations equivalent and sometimes superior to captive experimental studies without the drawbacks of the latter methods. Thus, we can now investigate complex cognition by accounting for many different factors, as required when solving tasks in nature. Combining both progresses allows us to move toward an “experience-specific cognition”, recognizing that cognition varies extensively in nature as individuals adapt to the precise challenges they experience in life. Such cognitive specialization makes cross-species comparisons more complex, while potentially identifying human cognitive uniqueness.

Is High-Intensity Interval Training Suitable to Promote Neuroplasticity and Cognitive Functions after Stroke?

Stroke-induced cognitive impairments affect the long-term quality of life. High-intensity interval training (HIIT) is now considered a promising strategy to enhance cognitive functions. This review is designed to examine the role of HIIT in promoting neuroplasticity processes and/or cognitive functions after stroke. The various methodological limitations related to the clinical relevance of studies on the exercise recommendations in individuals with stroke are first discussed. Then, the relevance of HIIT in improving neurotrophic factors expression, neurogenesis and synaptic plasticity is debated in both stroke and healthy individuals (humans and rodents). Moreover, HIIT may have a preventive role on stroke severity, as found in rodents. The potential role of HIIT in stroke rehabilitation is reinforced by findings showing its powerful neurogenic effect that might potentiate cognitive benefits induced by cognitive tasks. In addition, the clinical role of neuroplasticity observed in each hemisphere needs to be clarified by coupling more frequently to cellular/molecular measurements and behavioral testing.

Visual search under physical effort is faster but more vulnerable to distractor interference

Cognition and action are often intertwined in everyday life. It is thus pivotal to understand how cognitive processes operate with concurrent actions. The present study aims to assess how simple physical effort operationalized as isometric muscle contractions affects visual attention and inhibitory control. In a dual-task paradigm, participants performed a singleton search task and a handgrip task concurrently. In the search task, the target was a shape singleton among distractors with a homogeneous but different shape. A salient-but-irrelevant distractor with a unique color (i.e., color singleton) appeared on half of the trials (Singleton distractor present condition), and its presence often captures spatial attention. Critically, the visual search task was performed by the participants with concurrent hand grip exertion, at 5% or 40% of their maximum strength (low vs. high physical load), on a hand dynamometer. We found that visual search under physical effort is faster, but more vulnerable to distractor interference, potentially due to arousal and reduced inhibitory control, respectively. The two effects further manifest in different aspects of RT distributions that can be captured by different components of the ex-Gaussian model using hierarchical Bayesian method. Together, these results provide behavioral evidence and a novel model for two dissociable cognitive mechanisms underlying the effects of simple muscle exertion on the ongoing visual search process on a moment-by-moment basis.

High-intensity interval training and active video gaming improve neurocognition in schizophrenia: a randomized controlled trial

There is a need for treatments targeting neurocognitive dysfunctions in schizophrenia. The aim of this study was to investigate the neurocognitive effect of aerobic high-intensity interval training (HIIT). A comparison group performed sport simulating active video gaming (AVG). We anticipated that HIIT would improve neurocognition beyond any effect of AVG, due to engagement in higher intensity cardiorespiratory demands. Recent research on the beneficial neurocognitive effect of AVG challenges this expectation but added new relevance to comparing the two interventions. This is an observer-blinded randomized controlled trial. Eighty-two outpatients diagnosed with schizophrenia were allocated to HIIT (n = 43) or AVG (n = 39). Both groups received two supervised sessions per week for 12 weeks. The attrition rate was 31%, and 65% of the participants were defined as protocol compliant study completers. Intention-to-treat analyses showed significant improvements in the neurocognitive composite score from baseline to post-intervention and from baseline to 4 months follow-up in the total sample. The same pattern of results was found in several subdomains. Contrary to our hypothesis, we found no interaction effects of time and group, indicating equal effects in both groups. Separate within-group analysis unexpectedly showed trends of differential effects in the learning domain, as HIIT showed post-intervention improvement in verbal but not visual learning, while AVG showed improvement in visual but not verbal learning. HIIT and AVG improve neurocognition equally, suggesting that both interventions may be applied to target neurocognition in schizophrenia. Future research should investigate trends towards possible differential effects of exercise modes on neurocognitive subdomains. NCT02205684, 31.07.14.

The immune response and immune evasion characteristics in SARS-CoV, MERS-CoV, and SARS-CoV-2: Vaccine design strategies

The worldwide outbreak of SARS-CoV-2, severe acute respiratory syndrome coronavirus 2 as a novel human coronavirus, was the worrying news at the beginning of 2020. Since its emergence complicated more than 870,000 individuals and led to more than 43,000 deaths worldwide. Considering to the potential threat of a pandemic and transmission severity of it, there is an urgent need to evaluate and realize this new virus's structure and behavior and the immunopathology of this disease to find potential therapeutic protocols and to design and develop effective vaccines. This disease is able to agitate the response of the immune system in the infected patients, so ARDS, as a common consequence of immunopathological events for infections with Middle East respiratory syndrome coronavirus (MERS-CoV), SARS-CoV, and SARS-CoV-2, could be the main reason for death. Here, we summarized the immune response and immune evasion characteristics in SARS-CoV, MERS-CoV, and SARS-CoV-2 and therapeutic and prophylactic strategies with a focus on vaccine development and its challenges.

Voluntary exercise ameliorates synaptic pruning deficits in sleep-deprived adolescent mice

Adolescence is a critical period for brain development and adequate sleep during this period is essential for physical function and mental health. Emerging evidence has detailed the neurological impacts of sleep insufficiency on adolescents, as was unveiled by our previous study, microglia, one of the crucial contributors to synaptic pruning, is functionally disrupted by lack of sleep. Here, we provided evidence featuring the protective effect and the underlying mechanisms of voluntary exercise (VE) on microglial functions in an adolescent 72 h sleep deprivation (SD) model. We identified that the aberrant hippocampal neuronal activity and impaired short-term memory performance in sleep-deprived mice were prevented by 11 days of VE. VE significantly normalized the SD-induced dendritic spine increment and maintained the microglial phagocytic ability in sleep-deprived mice. Moreover, we found that the amendment of the noradrenergic signal in the central nervous system may explain the preventative effects of VE on the abnormalities of microglial and neuronal functions caused by SD. These data suggested that VE may confer protection to the microglia-mediated synaptic pruning in the sleep-deprived adolescent brains. Therefore, physical exercise could be a beneficial health practice for the adolescents that copes the adverse influence of inevitable sleep insufficiency.

High-intensity interval training is superior to moderate intensity training on aerobic capacity in rats: Impact on hippocampal plasticity markers

The use of endurance regimens could be improved by defining their respective effectiveness on aerobic fitness and brain health that remains controversial. We aimed at comparing work-matched high-intensity interval training (HIIT) with moderate-intensity continuous training (MICT) on aerobic performance and muscular plasticity markers in healthy rats. Cognitive functions and brain plasticity markers were also investigated following the 8-week training. Rats performed the incremental exercise test and behavioural tests before and after training at day 1 (D1), D15, D29 and D57. Key cerebral markers were assessed by Western blot and quantitative polymerase chain reaction to provide information on brain function related to angiogenesis, aerobic metabolism and neurotrophin activity at D59. Muscular protein levels involved in angiogenesis and aerobic metabolism were measured in both triceps brachii and soleus muscles. HIIT induced superior improvement of aerobic fitness compared to MICT, as indicated by enhancement of speed associated with lactate threshold (SLT) and maximal speed (Smax). In the triceps brachii muscle, markers of angiogenesis and aerobic activity were upregulated as well as myokines involved in neuroplasticity. Moreover, levels of key brain plasticity markers increased in the hippocampus after 8 weeks of HIIT, without improving cognitive functions. These findings might contribute to define physical exercise guidelines for maintaining brain health by highlighting the promising role of HIIT when using SLT for distinguishing low running speed from high running speed. Further studies are required to confirm these brain effects by exploring synaptic plasticity and neurogenesis mechanisms when exercise intensity is standardized and individualized.

Physically active learning in preschoolers: Improved self-regulation, comparable quantity estimation

BACKGROUND

Providing physical activity during the school day may mitigate increasingly sedentary lifestyles among children. Young children may be susceptible to interference during learning and consolidation when performing physical activity concurrently with academic instruction.

METHODS

Preschoolers (N = 72, mean age 5.1 ± 0.8 years, 50% female) completed a quantity estimation task before, following, and one week after engaging in either a 20-min physically active or sedentary lesson. Physical activity intensity and volume were measured using heart rate and pedometer step counts, respectively. Off-task behavior was recorded prior to and following the lesson.

RESULTS

Children exhibited similar learning and retention, but an added benefit of physically active lessons was a 1900% step increase and a 58% reduction in off-task behavior.

CONCLUSION

Providing physically active lessons instead of sitting for extended periods of time in early childhood classrooms reduces sedentary behavior and improves self-regulation while not interfering with educational outcomes.

Cerebral Hemodynamic and Neurotrophic Factor Responses Are Dependent on the Type of Exercise

This study examined acute cerebral hemodynamic and circulating neurotrophic factor responses to moderate intensity continuous exercise (MICT), guideline-based high intensity interval exercise (HIIT), and sprint interval exercise (SIT). We hypothesized that the pattern of middle cerebral artery velocity (MCAv) response would differ between interval and continuous exercise, with SIT inducing the smallest increase from rest, while increases in neurotrophic factors would be intensity-dependent. In a randomized crossover design, 24 healthy adults (nine females) performed three exercise protocols: (i) MICT (30 min), (ii) HIIT (4 × 4 min at 85% HRmax), and (iii) SIT (4 × 30 s supramaximal). MCAv significantly increased from rest across MICT (Δ13.1 ± 8.5 cm⋅s-1, p < 0.001) and all bouts of HIIT (Δ15.2 ± 9.8 cm⋅s-1, p < 0.001), but only for the initial bout of SIT (Δ17.3 ± 11.6 cm⋅s-1, p < 0.001). Immediately following each interval bout, MCAv increased (i.e., rebounded) for the SIT (9-14% above rest, p ≤ 0.04), but not HIIT protocol. SIT alone induced significant elevations from rest to end-exercise in vascular endothelial growth factor (VEGF; Δ28 ± 36%, p = 0.017) and brain-derived neurotrophic factor (BDNF, Δ149% ± 162%, p < 0.001) and there were greater increases in lactate than in either other protocol (>5-fold greater in SIT, p < 0.001), alongside a small significant reduction at the end of active recovery in insulin-like growth factor 1 (IGF-1, Δ22 ± 21%, p = 0.002). In conclusion, while the nature of the response may differ, both guideline-based and sprint-based interval exercise have the potential to induce significant changes in factors linked to improved cerebrovascular and brain health.

Chinese nutraceuticals and physical activity; their role in neurodegenerative tauopathies

The onset of neurodegenerative disease has not only been a major cause of scientific worry, but of economic burden to the health system. This condition has been further attributed to mis-stability, deletion or mutation of tau protein, causing the onset of Corticobasal degeneration, Pick's diseases, Progressive supranuclear palsy, Argyrophilic grains disease, Alzheimer's diseases etc. as scientifically renowned. This is mainly related to dysregulation of translational machinery, upregulation of proinflammatory cytokines and inhibition of several essential cascades such as ERK signaling cascade, GSK3β, CREB, and PKA/PKB (Akt) signaling cascades that enhances protein processing, normal protein folding, cognitive function, and microtubule associated tau stability. Administration of some nutrients and/or bioactive compounds has a high tendency to impede tau mediated inflammation at neuronal level. Furthermore, prevention and neutralization of protein misfolding through modulation of microtubule tau stability and prevention of protein misfolding is by virtue few of the numerous beneficial effects of physical activity. Of utmost important in this study is the exploration of promising bioactivities of nutraceuticals found in china and the ameliorating potential of physical activity on tauopathies, while highlighting animal and in vitro studies that have been investigated for comprehensive understanding of its potential and an insight into the effects on human highly probable to tau mediated neurodegeneration.

Voluntary exercise ameliorates the good limb training effect in a mouse model of stroke

Stroke is the leading cause of long-term disability in the United States, making research on rehabilitation imperative. Stroke rehabilitation typically focuses on recovery of the impaired limb, although this process is tedious. Compensatory use of the intact limb after stroke is more efficient, but it is known to negatively impact the impaired limb. Exercise may help with this problem; research has shown that exercise promotes neuronal growth and prevents cell death. This study used a mouse model to investigate if post-stroke exercise could prevent deterioration of the function of the impaired limb despite compensatory training of the intact limb. Results showed that mice that exercised, in combination with intact limb training, demonstrated improved functional outcome compared to mice that received no training or compensatory limb training only. These findings suggest that exercise can prevent the deterioration of impaired limb functional outcome that is typically seen with intact limb use.

Physical fitness, hippocampal functional connectivity and academic performance in children with overweight/obesity: The ActiveBrains project

OBJECTIVES

Physical fitness is a modifiable factor associated with enhanced brain health during childhood. To our knowledge, the present study is the first to examine: (i) whether physical fitness components (i.e., cardiorespiratory, motor and muscular fitness) are associated with resting state functional connectivity of hippocampal seeds to different cortical regions in children with overweight/obesity, and (ii) whether resting state hippocampal functional connectivity is coupled with better academic performance.

PATIENTS AND METHODS

In this cross-sectional study, a total of 99 children with overweight/obesity aged 8-11 years were recruited from Granada, Spain (November 2014 to February 2016). The physical fitness components were assessed following the ALPHA health-related fitness test battery. T1-weighted and resting-state fMRI images were acquired with a 3.0 Tesla Siemens Magnetom Tim Trio system. Academic performance was assessed by the Woodcock-Muñoz standardized test. Hippocampal seed-based procedures with post-hoc regression analyses were performed.

RESULTS

In the fully adjusted models, cardiorespiratory fitness was independently associated with greater hippocampal connectivity between anterior hippocampus and frontal regions (β ranging from 0.423 to 0.424, p < 0.001). Motor fitness was independently associated with diminished hippocampal connectivity between posterior hippocampus and frontal regions (β ranging from -0.583 to -0.694, p < 0.001). However, muscular fitness was not independently associated with hippocampal functional connectivity. Positive resting state hippocampal functional connectivity was related to better written expression (β ranging from 0.209 to 0.245; p < 0.05).

CONCLUSIONS

Physical fitness components may associate with functional connectivity between hippocampal subregions and frontal regions, independent of hippocampal volume, in children with overweight/obesity. Particularly, cardiorespiratory fitness may enhance anterior hippocampal functional connectivity and motor fitness may diminish posterior hippocampal functional connectivity. In addition, resting state hippocampal functional connectivity may relate to better written expression.

Exercise alters LPS-induced glial activation in the mouse brain

Experimental and epidemiological evidence suggest that modifiable lifestyle factors, including physical exercise, can build structural and cognitive reserve in the brain, increasing resilience to injury and insult. Accordingly, exercise can reduce the increased expression of proinflammatory cytokines in the brain associated with ageing or experimentally induced neuroinflammation. However, the cellular mechanisms by which exercise exerts this effect are unknown, including the effects of exercise on classic or alternative activation of astrocytes and microglia. In the present study, we assess the effects of nine consecutive days of treadmill running on the glial cell response to a single systemic injection of lipopolysaccharide (LPS) and, in parallel, the effects on spatial learning and memory. We show that prior exercise protects against LPS-induced impairment of performance in the object displacement task concomitant with attenuation of IL-1β, TNFα and IL-10 mRNA expression in the hippocampus. Assessment of isolated astrocytes and microglia revealed that LPS induced a proinflammatory response in these cells that was not observed in cells prepared from the brains of mice who had undergone prior exercise. The results suggest that exercise modulates neuroinflammation by reducing the proinflammatory microglial response, suggesting a mechanism by which exercise may be neuroprotective.

A dynamic microeconomic analysis of the impact of physical activity on cognition among older people

This microeconomic study explores the dynamic relationship between physical activity and cognition, using longitudinal data from 6 waves of the Survey of Health, Ageing and Retirement in Europe (SHARE) between 2004 and 2017. Physical activity has drawn significant attention as a potentially successful action for protecting brain health and cognition in the aging population, but the empirical evidence in observational studies is inconclusive to date. We add to the literature by estimating the effect of physical activity on cognition, tackling many sources of bias, which have previously not been addressed consistently. The challenge in estimating the effect of physical activity on cognition is the dynamics of cognition and the endogeneity of physical activity caused by unobserved heterogeneity, reverse causality and measurement error. To address this endogeneity and at the same time control for lagged cognition, we propose a system - generalized method of moments (GMM) estimator, using lagged levels and differences of the endogenous explanatory variables as instruments, while transforming out the fixed effects. We find that being moderately & vigorously physically active at least once a week increases memory status by 0.282 and 0.552 standard deviations for men and women respectively. We find different effects for varying physical activity intensity.

Sensor-measured sedentariness and physical activity are differentially related to fluid and crystallized abilities in aging

Aerobic exercise and physical activity (PA) are known to benefit cognition in adulthood. However, a typical older adult spends most of the day sedentary or in light PA, behaviors that are typically poorly captured by questionnaires. To better understand the associations between time spent in different intensities of lifestyle PA and cognition, we measured average time spent daily in sedentariness, light, and moderate to vigorous PA using hip-worn sensors (ActiGraph accelerometers). We studied baseline data from 228 cognitively normal adults (Age 60-80) who took part in a clinical trial (clinical study identifier: NCT01472744). Fluid (processing speed, memory, and reasoning) and crystallized abilities (vocabulary knowledge) were assessed with the Virginia Cognitive Aging Battery. Adjusting for age, sex, and several modifiable socioeconomic, physical and functional health factors, time spent daily in moderate to vigorous PA was positively related with fluid abilities (perceptual speed and reasoning). Furthermore, we found that those spending more time sedentary performed better on vocabulary knowledge and reasoning tasks. In contrast, time spent in light PA was not related to either fluid or crystallized abilities. Our results add to the previous literature by providing the first sensor-based evidence that crystallized and fluid abilities in older age may be associated with engagement in different intensities of daily activity. Moreover, our findings suggest that the behavior of moderate to vigorous PA is at least as important in relation to cognition as the desirable long-term physiological effects of higher intensity PA and exercise. (PsycInfo Database Record (c) 2020 APA, all rights reserved).

Does Aerobic and Resistance Exercise Influence Episodic Memory through Unique Mechanisms?

Aerobic and resistance exercise (acute and chronic) independently and collectively induce beneficial responses in the brain that may influence memory function, including an increase in cerebral blood flow, neurogenesis, neuroelectrical alterations, and protein production. However, whether aerobic and resistance exercise improve memory via similar or distinct mechanisms has yet to be fully explained. Here, we review the unique influence of aerobic and resistance exercise on neural modulation, proteins, receptors, and ultimately, episodic memory. Resistance training may optimize neural communication, information processing and memory encoding by affecting the allocation of attentional resources. Moreover, resistance exercise can reduce inflammatory markers associated with neural communication while increasing peripheral and central BDNF (brain-derived neurotrophic factor) production. Aerobic training increases hippocampal levels of BDNF and TrkB (Tropomyosin receptor kinase B), protein kinases and glutamatergic proteins. Likewise, both aerobic and anaerobic exercise can increase CREB (cAMP response element-binding protein) phosphorylation. Thus, we suggest that aerobic and resistance exercise may influence episodic memory via similar and, potentially, distinct mechanisms.

Mild Physical Activity Does Not Improve Spatial Learning in a Virtual Environment

It is well-established that physical exercise in humans improves cognitive functions, such as executive functions, pattern separation, and working memory. It is yet unknown, however, whether spatial learning, long known to be affected by exercise in rodents, is also affected in humans. In order to address this question, we recruited 20 healthy young male adults (18-30 years old) divided into exercise and control groups (n = 10 in each group). The exercise group performed three sessions per week of mild-intensity aerobic exercise for 12 weeks, while the control group was instructed not to engage in any physical activity. Both groups performed maximal oxygen uptake (VO_2max) tests to assess their cardiovascular fitness at baseline and every 4 weeks through the 12 weeks of the training program. The effects of mild aerobic exercise were tested on performance in two different virtual reality (VR)-based spatial learning tasks: (1) virtual Morris water maze (VMWM) and (2) virtual Radial arm water maze (VRAWM). Subjects were tested in both tasks at baseline prior to the training program and at the end of 12 weeks training program. While the mild-intensity aerobic exercise did not affect subjects' VO_2max parameters, mean time to anaerobic threshold increased for the exercise group compared with control. No effect was observed, however, on performance in the VMWM or VRAWM between the two groups. Based on these results, we suggest that mild-intensity aerobic exercise does not improve spatial learning and memory in young, healthy adults.

Examination of cortically projecting cholinergic neurons following exercise and environmental intervention in a rodent model of fetal alcohol spectrum disorders

BACKGROUND

Up to 1 in 5 infants in the United States are exposed to alcohol prenatally, resulting in neurodevelopmental deficits categorized as fetal alcohol spectrum disorders (FASD). Choline supplementation ameliorates some deficits, suggesting that alcohol exposure (AE) perturbs cholinergic neurotransmission and development. Behavioral interventions, which upregulate cholinergic neurotransmission, rescue cognitive deficits in rodent models of FASD.

METHODS

We investigated the impacts of two interventions (either wheel-running (WR) or "super intervention," WR plus exposure to a complex environment) on cholinergic neuronal morphology in the nucleus basalis of Meynert (NBM), the source of cortical cholinergic input, and prefrontal cortex (PFC) in a rodent model of FASD. One third of the total 47 male pups received intragastric intubation of ethanol in milk substitute during postnatal days (PD) 4-9. Another third served as sham-intubated procedural controls while the final third served as suckle controls. Rats from each group were exposed to either intervention during PD 30-72. Choline acetyltransferase (ChAT⁺ ) and acetylcholinesterase staining were used to quantify cholinergic neuron number, soma volume, and axon number.

RESULTS

Our data indicate a main effect of postnatal treatment on ChAT⁺ neuron number in NBM in adulthood. Post hoc analysis demonstrates that ChAT⁺ neuron number is reduced in AE compared to suckle control rodents (p < .01).

CONCLUSIONS

We examined the cytoarchitectonics of cholinergic neurons in NBM and PFC in adulthood following early postnatal AE and two interventions. We show that AE reduces ChAT⁺ neuron number in NBM, and this is not mitigated by either intervention.

COVID-19-The largest isolation study in history: the value of shared learnings from spaceflight analogs

The world is currently experiencing the largest isolation experiment in history. In an attempt to slow down the spread of the COVID-19 pandemic numerous countries across the world have been shutting down economies, education, and public life. Governments have mandated strict regulations of quarantine and social distancing in an unprecedented manner. The effects of these measures on brain, behavior, neuro-humoral and immunological responses in humans are largely unknown. Life science research for space exploration has a long history in using high-fidelity spaceflight analogs to better understand the effect of prolonged isolation and confinement on genes, molecules, cells, neural circuits, and physiological systems to behavior. We here propose to leverage the extensive experience and data from these studies and build a bridge between spaceflight research and clinical settings to foster transdisciplinary approaches to characterize the neurobehavioral effects on the immune system and vice versa. These approaches are expected to develop innovative and efficient health screening tools, diagnostic systems, and treatments to mitigate health risks associated with isolation and confinement on Earth and during future exploratory spaceflight missions.

Exercise Intervention in Treatment of Neuropsychological Diseases: A Review

Faced with a constant inundation of information and increasing pressures brought by the continuous development of modern civilization, people are increasingly faced with mental health challenges that are only now being actively researched. Mental illness is caused by brain dysfunction due to internal and external pathogenic factors that destroy the integrity of the human brain and alter its function. Regular participation in physical exercise can stimulate the cerebral cortex and simultaneously increase the supply of oxygen and nutrients, helping to preserve or restore normal functioning of the nervous system. In conjunction with other systems of the body, the nervous system constitutes the neuro-humoral regulation system responsible for maintaining the stable state of the human body. This paper is a systematic review of studies investigating the effects of exercise intervention on several common neuropsychological diseases, including depression, anxiety disorder, autism, and attention-deficit/hyperactivity disorder. Furthermore, we discuss possible physiological mechanisms underlying exercise-induced benefits and study limitations that must be addressed by future research. In many cases, drug therapy is ineffective and brings unwanted side effects. Based on the literature, we conclude that exercise intervention plays a positive role and that certain standards must be established in the field to make physical activity consistently effective.

Applying available knowledge and resources to alleviate familial and sporadic neurodegenerative disorders

Here I present the scientific rationale and implementation strategies for elimination of early-onset neurodegenerative disorders (EONDD) from future generations, and for risk reduction and treatments for the more common late-onset neurodegenerative disorders (LONDD). Young adults with a family history of an EONDD should be educated on the genetics and familial burden of EONDD. They can then be genotyped and, if positive for the mutation, counseled as to how they can ensure that none of their children will be affected by choosing either adoption or in vitro fertilization and preimplantation genetic testing. LONDD risk reduction will require education of physicians and patients on the benefits of regular intermittent bioenergetic and cognitive challenges (exercise, intermittent fasting, intellectual challenges and social engagement) for brain health, and on specific risk-reduction regimens. Regulations will be required to counteract the disease-promoting mercenary practices of the processed food and pharmaceutical industries. Clinical trials of pharmacological interventions should shift to small trials of agents that substantially mimic mechanisms of action of exercise and intermittent fasting to bolster neuronal bioenergetics and stress resistance.

Intrinsic Connectivity Changes Mediate the Beneficial Effect of Cardiovascular Exercise on Sustained Visual Attention

Cardiovascular exercise (CE) is an evidence-based healthy lifestyle strategy. Yet, little is known about its effects on brain and cognition in young adults. Furthermore, evidence supporting a causal path linking CE to human cognitive performance via neuroplasticity is currently lacking. To understand the brain networks that mediate the CE-cognition relationship, we conducted a longitudinal, controlled trial with healthy human participants to compare the effects of a 2-week CE intervention against a non-CE control group on cognitive performance. Concomitantly, we used structural and functional magnetic resonance imaging to investigate the neural mechanisms mediating between CE and cognition. On the behavioral level, we found that CE improved sustained attention, but not processing speed or short-term memory. Using graph theoretical measures and statistical mediation analysis, we found that a localized increase in eigenvector centrality in the left middle frontal gyrus, probably reflecting changes within an attention-related network, conveyed the effect of CE on cognition. Finally, we found CE-induced changes in white matter microstructure that correlated with intrinsic connectivity changes (intermodal correlation). These results suggest that CE is a promising intervention strategy to improve sustained attention via brain plasticity in young, healthy adults.

Postweaning Enriched Environment Enhances Cognitive Function and Brain-Derived Neurotrophic Factor Signaling in the Hippocampus in Maternally Separated Rats

Adverse environments during early life may lead to different neurophysiological and behavioral consequences, including depression and learning and memory deficits that persist into adulthood. Previously, we demonstrated that exposure to an enriched environment during adolescence mitigates the cognitive impairment observed after maternal separation in a task-specific manner. However, underlying neural mechanisms are still not fully understood. The current study examines the effects of neonatal maternal separation (MS) and postweaning environmental enrichment (EE) on spatial learning and memory performance in a short version of the Barnes Maze, active and passive behaviors in the forced swim test, and on TrkB/BDNF receptor expression in the hippocampus. Our results revealed that MS impaired acquisition learning and that enriched rats performed better than non-enriched rats in acquisition trials, regardless of early conditions. During the probe, enriched-housed rats demonstrated better performance than those reared in standard conditions. No significant differences between groups were found in the forced swim test. Both MS and EE increase full-length TrkB expression, and the combination of MS and EE treatment caused the highest levels of this protein expression. Similarly, truncated TrkB expression was higher in the MS/EE group. Animal facility rearing (AFR) non-enriched groups present the lowest activation of phosphorylated Erk, a canonical downstream kinase of TrkB signaling. Taken together, our results demonstrate the importance of enriched environment as an intervention to ameliorate the effects of maternal separation on spatial learning and memory. TrkB/BDNF signaling could mediate neuroplastic changes related to learning and memory during exposure to enriched environment.

Cardiovascular fitness and structural brain integrity: an update on current evidence

An aging global population and accompanying increases in the prevalence of age-related disorders are leading to greater financial, social, and health burdens. Aging-related dementias are one such category of age-related disorders that are associated with progressive loss of physical and cognitive integrity. One proposed preventative measure against risk of aging-related dementia is improving cardiovascular fitness, which may help reverse or buffer age-related brain atrophy associated with worse aging-related outcomes and cognitive decline. However, research into the beneficial potential of cardiovascular fitness has suffered from extreme heterogeneity in study design methodology leading to a lack of cohesion in the field and undermining any potential causal evidence that may exist. In addition, cardiovascular fitness and exercise are often conflated, leading to a lack of clarity in results. Here, I review recent literature on cardiovascular fitness, brain structure, and aging with the following goals: (a) to disentangle and lay out recent findings specific to aging, cardiovascular fitness, and brain structure, and (b) to ascertain the extent to which causal evidence actually exists. I suggest that, while there is some preliminary evidence for a link between cardiovascular fitness and brain structure in older adults, more research is still needed before definitive causal conclusions can be drawn. I conclude with a discussion of existing gaps in the field and suggestions for how they may be addressed by future research.

Differential impact of stress and environmental enrichment on corticolimbic circuits

Stress exposure can produce profound changes in physiology and behavior that can impair health and well-being. Of note, stress exposure is linked to anxiety disorders and depression in humans. The widespread impact of these disorders warrants investigation into treatments to mitigate the harmful effects of stress. Pharmacological treatments fail to help many with these disorders, so recent work has focused on non-pharmacological alternatives. One of the most promising of these alternatives is environmental enrichment (EE). In rodents, EE includes social, physical, and cognitive stimulation for the animal, in the form of larger cages, running wheels, and toys. EE successfully reduces the maladaptive effects of various stressors, both as treatment and prophylaxis. While we know that EE can have beneficial effects under stress conditions, the morphological and molecular mechanisms underlying these behavioral effects are still not well understood. EE is known to alter neurogenesis, dendrite development, and expression of neurotrophic growth factors, effects that vary by type of enrichment, age, and sex. To add to this complexity, EE has differential effects in different brain regions. Understanding how EE exerts its protective effects on morphological and molecular levels could hold the key to developing more targeted pharmacological treatments. In this review, we summarize the literature on the morphological and molecular consequences of EE and stress in key emotional regulatory pathways in the brain, the hippocampus, prefrontal cortex, and amygdala. The similarities and differences among these regions provide some insight into stress-EE interaction that may be exploited in future efforts toward prevention of, and intervention in, stress-related diseases.

The Effects of High-intensity Functional Training (HIFT) on Spatial Learning, Visual Pattern Separation and Attention Span in Adolescents

Aerobic, anaerobic, and strength exercises are known to improve various cognitive functions, such as executive functions, pattern separation, and working memory. High-intensity functional training (HIFT) is a form of physical activity that can be modified to any fitness level and elicits greater muscle recruitment than repetitive aerobic exercises, thereby improving cardiovascular endurance, strength, and flexibility. HIFT emphasizes functional, multi-joint movements via high-intensity interval training (HIIT) and muscle-strengthening exercises. It is yet unknown, however, whether HIFT affects cognitive functions in adolescents. To address this question, we subjected adolescents to 3 × 20 min training sessions/week of HIFT for 3 months. The effects of HIFT were tested on performance in: (1) virtual reality (VR)-based spatial learning task; (2) computerized visual pattern separation; and (3) attention span. The control group performed a typical physical class three times per week. The effects on cognition were tested at baseline and following 3 months of HIFT. Three months into the intervention, the HIFT group achieved higher scores in the spatial learning task, pattern separation task, and in the attention span test, compared with controls. These data suggest that HIFT can potentially translate into improving school performance in adolescents.

Aerobic exercise delays retinal ganglion cell death after optic nerve injury

Aerobic exercise has been shown to play a crucial role in preventing neurological diseases and improving cognitive function. In the present study, we investigated the effect of treadmill training on retinal ganglion cells (RGCs) following optic nerve transection in adult rats. We exercised the rats on a treadmill for 5 d/week (30 min/d at a rate of 9 m/min) or placed control rats on static treadmills. After 3 weeks of exercise, the left optic nerve of each rat was transected. After the surgery, the rat was exercised for another week. The percentages of surviving RGCs in the axotomized eyes of inactive rats were 67% and 39% at 5 and 7 days postaxotomy, respectively. However, exercised rats had significant more RGCs at 5 (74% survival) and 7 days (48% survival) after axotomy. Moreover, retinal brain-derived neurotrophic factor (BDNF) protein levels were significantly upregulated in response to exercise compared with those in the axotomized eyes of inactive rats. Blocking BNDF signaling during exercise by intraperitoneal injections of ANA-12, a BDNF tropomyosin receptor kinase (TrkB) receptor antagonist, reduced the number of RGCs in exercised rats to the level of RGCs in the inactive rats, effectively abolishing the protection of RGCs afforded by exercise. The results suggest that treadmill training effectively rescues RGCs from neurodegeneration following optic nerve transection by upregulating the expression of BDNF.

Exercise for Older Adults Improves the Quality of Life in Parkinson's Disease and Potentially Enhances the Immune Response to COVID-19

Parkinson's disease (PD) is a progressive neurodegenerative disorder brought about due to dopaminergic neuronal cell loss in the midbrain substantia nigra pars compacta region. PD presents most commonly in older adults and is a disorder of both motor and nonmotor dysfunction. The novel SARS-CoV-2 virus is responsible for the recent COVID-19 pandemic, and older individuals, those with preexisting medical conditions, or both have an increased risk of developing COVID-19 with more severe outcomes. People-with-Parkinson's (PwP) of advanced age can have both immune and autonomic nervous problems that potentially lead to pre-existing pulmonary dysfunction and higher infection risk, increasing the probability of contracting COVID-19. A lifestyle change involving moderate-intensity exercise has the potential to protect against SARS-CoV-2 through strengthening the immune system. In addition to a potential protective measure against SARS-CoV-2, exercise has been shown to improve quality-of-life (QoL) in PD patients. Recent studies provide evidence of exercise as both neuroprotective and neuroplastic. This article is a literature review investigating the role exercise plays in modifying the immune system, improving health outcomes in PwP, and potentially acting as a protective measure against SARS-Cov-2 infection. We conclude that exercise, when correctly performed, improves QoL and outcomes in PwP, and that the enhanced immune response from moderate-intensity exercise could potentially offer additional protection against COVID-19.