Exercise-induced cognitive plasticity, implications for mild cognitive impairment and Alzheimer's disease

Moderate aerobic training enhances the effectiveness of insulin therapy through hypothalamic IGF1 signaling in rat model of Alzheimer's disease

Alzheimer's disease (AD) is a neurological condition that is connected with a decline in a person's memory as well as their cognitive ability. One of the key topics of AD research has been the exploration of metabolic causes. We investigated the effects of treadmill exercise and intranasal insulin on learning and memory impairment and the expression of IGF1, BDNF, and GLUT4 in hypothalamus. The animals were put into 9 groups at random. In this study, we examined the impact of insulin on spatial memory in male Wistar rats and analyzed the effects of a 4-week pretreatment of moderate treadmill exercise and insulin on the mechanisms of improved hypothalamic glucose metabolism through changes in gene and protein expression of IGF1, BDNF, and GLUT4. We discovered that rat given Aβ25-35 had impaired spatial learning and memory, which was accompanied by higher levels of Aβ plaque burden in the hippocampus and lower levels of IGF1, BDNF, and GLUT4 mRNA and protein expression in the hypothalamus. Additionally, the administration of exercise training and intranasal insulin results in the enhancement of spatial learning and memory impairments, the reduction of plaque burden in the hippocampus, and the enhancement of the expression of IGF1, BDNF, and GLUT4 in the hypothalamus of rats that were treated with Aβ25-35. Our results show that the improvement of learning and spatial memory due to the improvement of metabolism and upregulation of the IGF1, BDNF, and GLUT4 pathways can be affected by pretreatment exercise and intranasal insulin.

Overexpression of α-Klotho isoforms promotes distinct Effects on BDNF-Induced Alterations in Dendritic Morphology

α-Klotho (α-Kl) is a modulator of aging, neuroprotection, and cognition. Transcription of the Klotho gene produces two splice variants-a membrane protein (mKl), which can be cleaved and released into the extracellular milieu, and a truncated secreted form (sKl). Despite mounting evidence supporting a role for α-Kl in brain function, the specific roles of α-Kl isoforms in neuronal development remain elusive. Here, we examined α-Kl protein levels in rat brain and observed region-specific expression in the adult that differs between isoforms. In the developing hippocampus, levels of isoforms decrease after the third postnatal week, marking the end of the critical period for development. We overexpressed α-Kl isoforms in primary cultures of rat cortical neurons and evaluated effects on brain-derived neurotrophic factor (BDNF) signaling. Overexpression of either isoform attenuated BDNF-mediated signaling and reduced intracellular Ca2+ levels, with mKl promoting a greater effect. mKl or sKl overexpression in hippocampal neurons resulted in a partially overlapping reduction in secondary dendrite branching. Moreover, mKl overexpression increased primary dendrite number. BDNF treatment of neurons overexpressing sKl resulted in a dendrite branching phenotype similar to control neurons. In neurons overexpressing mKl, BDNF treatment restored branching of secondary and higher order dendrites close, but not distal, to the soma. Taken together, the data presented support the idea that sKl and mKl play distinct roles in neuronal development, and specifically, in dendrite morphogenesis.

14-Week exercise training modifies the DNA methylation levels at gene sites in non-Alzheimer's disease women aged 50 to 70 years

Exercise training emerges as a key strategy in lifestyle modification, capable of reducing the risk of developing Alzheimer's disease (AD) due to risk factors such as age, family history, genetics and low level of education associated with AD. We aim to analyze the effect of a 14-week combined exercise training (CT) on the methylation of genes associated with AD in non-alzheimer's disease women. CT sessions lasted 60 min, occurring three times a week for 14 weeks. Forty non-Alzheimer's disease women aged 50 to 70 years (60.7 ± 4.1 years) with a mean height of 1.6 ± 0.1 m, mean weight of 73.12 ± 9.0 kg and a mean body mass index of 29.69 ± 3.5 kg/m2, underwent two physical assessments: pre and post the 14 weeks. DNA methylation assays utilized the EPIC Infinium Methylation BeadChip from Illumina. We observed that 14 weeks of CT led to reductions in systolic (p = 0.001) and diastolic (p = 0.017) blood pressure and improved motor skills post-intervention. Among 25 genes linked to AD, CT induced differentially methylated sites in 12 genes, predominantly showing hypomethylated sites (negative β values). Interestingly, despite hypomethylated sites, some genes exhibited hypermethylated sites (positive β values), such as ABCA7, BDNF, and WWOX. A 14-week CT regimen was adequate to induce differential methylation in 12 CE-related genes in healthy older women, alongside improvements in motor skills and blood pressure. In conclusion, this study suggest that combined training can be a strategy to improve physical fitness in older individuals, especially able to induce methylation alterations in genes sites related to development of AD. It is important to highlight that training should act as protective factor in older adults.

Fractal Phototherapy in Maximizing Retina and Brain Plasticity

The neuroplasticity potential is reduced with aging and impairs during neurodegenerative diseases and brain and visual system injuries. This limits the brain's capacity to repair the structure and dynamics of its activity after lesions. Maximization of neuroplasticity is necessary to provide the maximal CNS response to therapeutic intervention and adaptive reorganization of neuronal networks in patients with degenerative pathology and traumatic injury to restore the functional activity of the brain and retina.Considering the fractal geometry and dynamics of the healthy brain and the loss of fractality in neurodegenerative pathology, we suggest that the application of self-similar visual signals with a fractal temporal structure in the stimulation therapy can reactivate the adaptive neuroplasticity and enhance the effectiveness of neurorehabilitation. This proposition was tested in the recent studies. Patients with glaucoma had a statistically significant positive effect of fractal photic therapy on light sensitivity and the perimetric MD index, which shows that methods of fractal stimulation can be a novel nonpharmacological approach to neuroprotective therapy and neurorehabilitation. In healthy rabbits, it was demonstrated that a long-term course of photostimulation with fractal signals does not harm the electroretinogram (ERG) and retina structure. Rabbits with modeled retinal atrophy showed better dynamics of the ERG restoration during daily stimulation therapy for a week in comparison with the controls. Positive changes in the retinal function can indirectly suggest the activation of its adaptive plasticity and the high potential of stimulation therapy with fractal visual stimuli in a nonpharmacological neurorehabilitation, which requires further study.

Neuroprotective potential of sevoflurane against isoflurane induced cognitive dysfunction in rats via anti-inflammatory and antioxidant effect

PURPOSE

Intravenous anesthetics have excellent analgesic activity without inducing the side effect in the respiratory system. The aim and objective of the current experimental study was to access the neuroprotective effect of sevoflurane against isoflurane induced cognitive dysfunction in rats.

METHODS

Isoflurane was used for induction the neurodysfunction in the rats, and rats received the oral administration of sevoflurane (2.5, 5 and 10 mg/kg). Morris water test was carried out for the estimation of cognitive function. Neurochemical parameters, antioxidant parameters and pro-inflammatory cytokines were also estimated.

RESULTS

Sevoflurane significantly (P < 0.001) altered the neurochemical parameters such as anti-choline acetyltransferase, acetylcholine esterase, acetylcholine, protein carbonyl, choline brain-derived neurotrophic factor, and amyloid β; antioxidant parameters such as glutathione, superoxide dismutase, and malondialdehyde; pro-inflammatory cytokines include interleukin (IL-2, IL-10, IL-4, IL-6, IL-10, IL-1β), and tumor necrosis factor-α. Sevoflurane significantly reduced the activity of caspase-3.

CONCLUSIONS

Sevoflurane exhibited the neuroprotection against the cognitive dysfunction in rats via anti-inflammatory and antioxidant mechanism.

Repositioning of Anti-Diabetic Drugs against Dementia: Insight from Molecular Perspectives to Clinical Trials

Insulin resistance as a hallmark of type 2 DM (T2DM) plays a role in dementia by promoting pathological lesions or enhancing the vulnerability of the brain. Numerous studies related to insulin/insulin-like growth factor 1 (IGF-1) signaling are linked with various types of dementia. Brain insulin resistance in dementia is linked to disturbances in Aβ production and clearance, Tau hyperphosphorylation, microglial activation causing increased neuroinflammation, and the breakdown of tight junctions in the blood-brain barrier (BBB). These mechanisms have been studied primarily in Alzheimer's disease (AD), but research on other forms of dementia like vascular dementia (VaD), Lewy body dementia (LBD), and frontotemporal dementia (FTD) has also explored overlapping mechanisms. Researchers are currently trying to repurpose anti-diabetic drugs to treat dementia, which are dominated by insulin sensitizers and insulin substrates. Although it seems promising and feasible, none of the trials have succeeded in ameliorating cognitive decline in late-onset dementia. We highlight the possibility of repositioning anti-diabetic drugs as a strategy for dementia therapy by reflecting on current and previous clinical trials. We also describe the molecular perspectives of various types of dementia through the insulin/IGF-1 signaling pathway.

The influence of exercise interventions on cognitive functions in patients with amnestic mild cognitive impairment: A systematic review and meta-analysis

Introduction

Patients with amnestic mild cognitive impairment (aMCI) are more likely to develop dementia compared to patients with non-aMCI (naMCI). Among the mixed samples of aMCI and naMCI, exercise interventions are effective for patients with MCI to improve cognitive functions. However, the influence of exercise interventions on patients with aMCI is still unclear.

Objective

The objective of this systematic review and meta-analysis is to evaluate the influence of exercise interventions on cognitive functions in patients with aMCI.

Methods

Four literature databases (PubMed, Web of Science, EBSCO, and Cochrane Library) and three Chinese databases (China National Knowledge Infrastructure, Wanfang, and China Science and Technology Journal Database) were searched from their inception to August 31, 2022. Based on the preliminary search of seven databases and their cited references, a total of 2,290 records were identified. Finally, 10 studies with a total of 28 data points involving 575 participants with aMCI were included in this meta-analysis. If the measurements of outcomes were different among studies, the effect size was synthesized using the standardized mean difference (SMD) with a 95% confidence interval (CI). If the measurements were the same, the weight mean difference (WMD) with a 95% CI was used to integrate the effect size.

Data synthesis

The results showed that exercise interventions had no significant effects on improving several specific domains of cognitive functions including working memory (WMD = -0.05; 95% CI = -0.74 to 0.63; p = 0.88; I ² = 78%) and attention (SMD = 0.20; 95% CI = -0.31 to 0.72; p = 0.44; I ² = 60%). Additionally, exercise interventions had a significant effect on global cognitive function (SMD = 0.70; 95% CI = 0.50-0.90; p < 0.00001; I ² = 29%) and some specific cognitive domains including immediate recall (SMD = 0.55; 95% CI = 0.28-0.81; p < 0.0001; I ² = 0%), delayed recall (SMD = 0.66; 95% CI = 0.45-0.87; p < 0.00001; I ² = 37%), and executive function (SMD = 0.38; 95% CI = 0.16-0.60; p= 0.0006; I ² = 4%). Furthermore, subgroup analysis based on the intervention forms indicated that multi-component interventions (SMD = 0.44; 95% CI = 0.11-0.77; p = 0.009; I ² = 0%) appeared to be less effective than the single-component intervention (SMD = 0.85; 95% CI = 0.60-1.10; p < 0.00001; I ² = 10%) in terms of boosting global cognitive function.

Conclusion

This meta-analysis suggests that the exercise can help patients with aMCI improve global cognitive function. And exercise interventions have positive influence on enhancing several specific cognitive domains such as immediate recall, delayed recall, and executive function.Systematic review registration: http://www.crd.york.ac.uk/PROSPERO, identifier: CRD42022354235.

Exercise to Improve Postural Stability in Older Adults with Alzheimer's Disease: A Systematic Review of Randomized Control Trials

In this systematic review, we aim to synthesize published evidence on the effects of exercise in improving postural stability among older adults with Alzheimer's Disease (AD). A systematic electronic literature search was undertaken in Pedro, Cochrane, MEDLINE, ProQuest, Science direct and Clinical trial databases involving human participants published from year 2000-2022. This search was updated in June 2022. The studies chosen were based on predetermined criteria. Data relating to the contents and parameters of exercise in persons with AD were gathered and analyzed. A total of 8 experimental studies met the inclusion criteria. Overall, the selected studies were of a medium quality. In these studies, information and physical exercises were used to improve postural stability in older adults with AD. The findings of the review suggest that performing combined strength, balance and executive function training can improve postural stability. However, we are unable to conclude the specific dose for specific type of exercise. More high-quality studies are required pertaining to exercise prescription for older adults with AD. Mostly, information and physical exercise were delivered via face-to-face sessions conducted by health professionals. The structure of exercises summarized in this review may be beneficial for older adults with AD to improve postural stability and as a result reduce falls.

An integrated intervention of computerized cognitive training and physical exercise in virtual reality for people with Alzheimer's disease: The jDome study protocol

Introduction

Alzheimer's disease is a neurodegenerative syndrome characterized by cognitive deficits, loss of daily functions, and mental and behavioral disorders, which cause stress and negatively affect the quality of life. Studies in the field suggest that combining cognitive training with physical activity can reduce the risk of developing the disease and, once neurodegeneration has begun, it slows its progress. In particular, virtual reality and augmented reality administer cognitive stimulation while providing a link to autobiographical memory through reminiscence, enabling the improvement of the person's quality of life. The present protocol aims to evaluate the effectiveness of cognitive and physical treatments, integrated with the addition of virtual reality and reminiscence elements, using the Brainer software, in which people will find cognitive training, and the jDome® BikeAround™ system, which will allow participants to pedal along a personalized path projected on a schematic, using an exercise bike connected to the system.

Methods and analysis

For this study, 78 patients with mild Alzheimer's dementia were recruited and divided into the Experimental Group (EG) and Control Group (CG). Sixteen treatment sessions of 60 min each were conducted for both groups (2 training sessions per week, for 8 weeks), including 1 patient at a time. The EG received cognitive treatment with Brainer and physical training with jDome, while the CG received cognitive treatment with Brainer and physical training with a classic bicycle. The evaluation mainly focused on the assessment of the person's cognitive status. Other analyses were conducted on the quality of life, mood, behavioral disorders, and physical function, which were considered secondary outcomes.

Discussions

The ultimate goal of the present study is to test the effectiveness of a treatment for people with mild Alzheimer's focused on the integration of cognitive training and aerobic physical activity, using an exercise bike, with the addition of virtual reality and reminiscence elements.

Ethics and dissemination

The study was approved by the Ethics Committee of the IRCCS INRCA. It was recorded in ClinicalTrials.gov on 2 June 2022 with the number NCT05402423. The study findings will be used for publication in peer-reviewed scientific journals and presentations in scientific meetings.

The Effects of High-Intensity Functional Training on Cognition in Older Adults with Cognitive Impairment: A Systematic Review

(1) Background: High-Intensity Functional Training (HIFT) is a new exercise modality that emphasizes multi-joint functional movements adaptable to any fitness level and promotes greater muscle recruitment. Previous studies have evaluated the positive effects of HIFT on mental and cognitive health but have not evaluated it in older people. This study aims to conduct a systematic review of randomized controlled trials assessing the effects of HIFT on general cognition in older adults with cognitive impairment. (2) Methods: Following the PRISMA 2020 guideline, articles that did a high-intensity functional physical exercise intervention on cognitive performance in older adults with mild to moderate cognitive impairment (MMSE > 10) or dementia, aged 55 years or older, published between 2011 and 2021 in five different electronic databases: PubMed, Web of Science, Scopus, CINAHL, and Cochrane plus were included. (3) Results: 7 articles were included, all having general cognition as their primary outcome. All assessed general cognition using the Mini-Mental State Examination, the ADAS-Cog, or both. All studies had at least one HIFT experimental group with a frequency of 2 sessions per week and a variable duration between protocols of 12, 13, 16, and 26 weeks. Two articles showed that a progressive HIFT program improves general cognition, four articles showed no significant changes within or between groups and one article concluded that a HIFT intervention does not slow cognitive decline. (4) Conclusions: Evidence exists of the benefits of HIFT on general cognition in older adults with cognitive impairment, assessed using the MMSE, the ADAS-cog, or both. Two articles that showed improvement in cognitive function used progressive HIFT with 80% RM at 6, 12, and 1 weeks; however, in the other articles, due to the heterogeneity of intervention protocols, measurement time points, and control group activities, mixed results were evidenced

The effect of combined cognitive intervention and physical exercise on cognitive function in older adults with mild cognitive impairment: a meta-analysis of randomized controlled trials

BACKGROUND

The state of mild cognitive impairment (MCI) provides an optimal window for preventing progression to dementia. Combined cognitive intervention and physical exercise may yield additive and synergistic effects on cognition in older adults with MCI.

OBJECTIVES

The purpose of this study was to assess the efficacy of a combined intervention to improve cognition in older adults with MCI by comparing a control group that underwent only cognitive intervention, a control group that underwent only physical exercise, and a control group that did not undergo cognitive intervention or physical exercise.

DESIGN

Meta-analysis of randomized controlled trials (RCTs).

DATA SOURCES

The online databases of PubMed, Web of Science, Embase, the Cochrane Library, PsycINFO, and CINAHL were systematically searched.

REVIEW METHODS

The outcomes were global cognition, memory, and executive function/attention. A sensitivity analysis was conducted when the I² statistic was > 50%.

RESULTS

A total of 16 studies were included. The results showed that the combined intervention had positive effects on global cognition compared to the effects of the other control group [SMD = 0.27, 95% CI (0.09, 0.44), p = 0.003]. Regarding memory, the combined intervention had positive effects compared to the effects observed in the single physical exercise group [SMD = 0.25, 95% CI (0.07, 0.44), p = 0.006] and the other control group [SMD = 0.29, 95% CI (0.12, 0.47), p = 0.001]. For executive function/attention, the combined intervention had also positive effects compared to the effects of the single cognitive intervention group [SMD = 0.28, 95% CI (0.09, 0.47), p = 0.004], the single physical exercise group [SMD = 0.32, 95% CI (0.16, 0.49), p = 0.0002], and the other control group [SMD = 0.23, 95% CI (0.05, 0.41), p = 0.01].

CONCLUSIONS

The combined intervention resulted in cognitive benefits in older adults with MCI and exhibited limited superiority over the single cognitive intervention and the single physical exercise on cognitive subdomains.

Human muscle stem cells are refractory to aging

Age-related loss of muscle mass and strength is widely attributed to limitation in the capacity of muscle resident satellite cells to perform their myogenic function. This idea contains two notions that have not been comprehensively evaluated by experiment. First, it entails the idea that we damage and lose substantial amounts of muscle in the course of our normal daily activities. Second, it suggests that mechanisms of muscle repair are in some way exhausted, thus limiting muscle regeneration. A third potential option is that the aged environment becomes inimical to the conduct of muscle regeneration. In the present study, we used our established model of human muscle xenografting to test whether muscle samples taken from cadavers, of a range of ages, maintained their myogenic potential after being transplanted into immunodeficient mice. We find no measurable difference in regeneration across the range of ages investigated up to 78 years of age. Moreover, we report that satellite cells maintained their myogenic capacity even when muscles were grafted 11 days postmortem in our model. We conclude that the loss of muscle mass with increasing age is not attributable to any intrinsic loss of myogenicity and is most likely a reflection of progressive and detrimental changes in the muscle microenvironment such as to disfavor the myogenic function of these cells.

Body adaptation to Dance: A Gerontological Perspective

A number of studies have investigated the effectiveness of dance in older adults in the context of healthy aging. Analysing results across studies is important to understand whether dance in older adults is an effective adjunctive intervention for the healthy aging. To summarize the current research results about the effectiveness of dance in older adults in the context of healthy aging, and to identify key areas for future research. The search was conducted in Web of Science, PubMed and Google Scholar databases, using the following search string and Boolean logic (‘AND’, ‘OR’) locating studies published between database inception and September 2018: Dance OR contemporary dance OR ballroom dance OR Latin dance OR standard dance OR hip-hop dance OR tango AND Cardiovascular OR circulation AND Emotion OR well-being OR blood pressure OR disease OR thrombosis OR vascular OR glucose OR blood OR cardiac OR mental OR heart rate. Two reviewers independently extracted studies data. Eight suitable publications were included. The results showed that dance promote improvements in cognitive parameters when compared to other types of exercise or no-exercise. Significant effects were found on some physiological parameters, even after a short intervention period. Dance proved to be able to assist older adults in the context of healthy aging. The improvements in the cognitive, physiological and motor control parameters are very relevant for this population, due to the impact in a better quality of life.

The pleiotropic neuroprotective effects of resveratrol in cognitive decline and Alzheimer's disease pathology: From antioxidant to epigenetic therapy

While the elderly segment of the population continues growing in importance, neurodegenerative diseases increase exponentially. Lifestyle factors such as nutrition, exercise, and education, among others, influence ageing progression, throughout life. Notably, the Central Nervous System (CNS) can benefit from nutritional strategies and dietary interventions that prevent signs of senescence, such as cognitive decline or neurodegenerative diseases such as Alzheimer's disease and Parkinson's Disease. The dietary polyphenol Resveratrol (RV) possesses antioxidant and cytoprotective effects, producing neuroprotection in several organisms. The oxidative stress (OS) occurs because of Reactive oxygen species (ROS) accumulation that has been proposed to explain the cause of the ageing. One of the most harmful effects of ROS in the cell is DNA damage. Nevertheless, there is also evidence demonstrating that OS can produce other molecular changes such as mitochondrial dysfunction, inflammation, apoptosis, and epigenetic modifications, among others. Interestingly, the dietary polyphenol RV is a potent antioxidant and possesses pleiotropic actions, exerting its activity through various molecular pathways. In addition, recent evidence has shown that RV mediates epigenetic changes involved in ageing and the function of the CNS that persists across generations. Furthermore, it has been demonstrated that RV interacts with gut microbiota, showing modifications in bacterial composition associated with beneficial effects. In this review, we give a comprehensive overview of the main mechanisms of action of RV in different experimental models, including clinical trials and discuss how the interconnection of these molecular events could explain the neuroprotective effects induced by RV.

Potential Genetic Contributions of the Central Nervous System to a Predisposition to Elite Athletic Traits: State-of-the-Art and Future Perspectives

Recent remarkable advances in genetic technologies have allowed for the identification of genetic factors potentially related to a predisposition to elite athletic performance. Most of these genetic variants seem to be implicated in musculoskeletal and cardiopulmonary functions. Conversely, it remains unclear whether functions of the central nervous system (CNS) genetically contribute to elite athletic traits, although the CNS plays critical roles in exercise performance. Accumulating evidence has highlighted the emerging implications of CNS-related genes in the modulation of brain activities, including mental performance and motor-related traits, thereby potentially contributing to high levels of exercise performance. In this review, recent advances are summarized, and future research directions are discussed in regard to CNS-related genes with potential roles in a predisposition to elite athletic traits.

Interval aerobic training improves bioenergetics state and mitochondrial dynamics of different brain regions in restraint stressed rats

Evidence has validated the prophylactic effects of exercising on different aspects of health. On the opposite side, immobilization may lead to various destructive effects causing neurodegeneration. Here, we investigated the association between exercising and mitochondrial quality for preventing the destructive effects of restraint stress in different rat brain regions. Twenty-four male Wistar rats, were randomized into four groups (n = 6), exercise, stress, exercise + stress, and control. The exercise procedure consisted of running on a rodent treadmill for 8 weeks, and rats in the stress group were immobilized for 6 h. Rats were then euthanized by decapitation and tricarboxylic acid (TCA) cycle enzyme activity, antioxidant levels, and mitochondrial biogenesis factors were assessed in the frontal, hippocampus, parietal and temporal regions using spectrophotometer and western blot technique. Based on our results, increased activity of TCA cycle enzymes in the exercised and exercise-stressed groups was detected, except for malate dehydrogenase which was decreased in exercise-stressed group, and fumarase that did not change. Furthermore, the level of antioxidant agents (superoxide dismutase and reduced glutathione), mitochondrial biogenesis factors (peroxisome proliferator-activated receptor gamma coactivator 1-alpha and mitochondrial transcription factor A), and dynamics markers (Mitofusin 2, dynamic related protein 1, PTEN induced putative kinase-1, and parkin) increased in both mentioned groups. Interestingly our results also revealed that the majority of the mitochondrial factors increased in the frontal and parietal lobes, which may be in relation with the location of motor and sensory areas. Exercise can be used as a prophylactic approach against bioenergetics and mitochondrial dysfunction.

A randomized trial of physical activity for cognitive functioning in breast cancer survivors: Rationale and study design of I Can! Improving Cognition After Cancer

INTRODUCTION

Difficulties with cognition are extremely common among breast cancer survivors and can significantly impact quality of life, daily functioning, and ability to return to work. One promising intervention is increasing physical activity, as it has been effective in improving cognition in non-cancer populations. Few physical activity intervention trials with cognition outcomes have included cancer survivors. This project builds upon our previous work indicating that increased physical activity can improve objectively measured processing speed and self-reported cognition among breast cancer survivors.

METHODS

The I Can! study will examine whether a physical activity intervention improves cognition among 250 post-treatment breast cancer survivors (Stages I-III, <5 years post-treatment) who are reporting cognitive difficulties. This 2-arm randomized controlled trial comparing a 6-month physical activity intervention (Exercise Group) to a health & wellness attention-comparison condition (Health & Wellness Group) will examine intervention effects on cognition (at 3 and 6 months) and maintenance of effects at 12 months. The primary aim is to investigate the impact of exercise on objectively measured processing speed and self-reported cognition. Secondary aims are to investigate maintenance of cognitive changes and examine candidate biological mechanisms and psychological mediators.

CONCLUSION

The I Can! study will contribute to the scientific, public health, and survivorship intervention literature by providing new information on the impact of physical activity for cognitive impairment in breast cancer survivors. Findings from this study will inform guidelines for physical activity to improve the lives of millions of breast cancer survivors.

Effects of physical activities on dementia-related biomarkers: A systematic review of randomized controlled trials

INTRODUCTION

Physical activities (PA) may lead to improved cognition in mild cognitive impairment (MCI), Alzheimer's disease (AD), and dementia. The mechanisms mediating potential PA effects are unknown. Assessment of PA effects on relevant biomarkers may provide insights into mechanisms underlying potential PA effects on cognition.

METHODS

We systematically reviewed randomized controlled trials (RCTs) that studied PA effects on biomarkers in MCI, AD, and dementia populations. We examined whether biological mechanisms were hypothesized to explain associations among PA, biomarkers, and cognitive functions. We used the PubMed database and searched for RCTs with PA until October 31, 2019.

RESULTS

Of 653 studies examining changes in biomarkers in PA trials, 18 studies met inclusion criteria for the present review. Some studies found favorable effects of PA on neurotrophic and inflammatory biomarkers. AD pathological markers were rarely investigated, with inconclusive results. Most studies were relatively small in sample size, of limited duration, and not all studies compared the changes in biomarkers between the control and experimental groups.

DISCUSSION

There is only limited use of potentially informative biomarkers in PA trials for MCI, AD, and dementia. Most studies did not examine the role of biomarkers to study associations between PA and cognitive functions in their analyses. Several potential biomarkers remain uninvestigated. Careful use of biomarkers may clarify mechanisms underlying PA effects on cognition. Our review serves as a useful resource for developing future PA RCTs aimed at improving cognitive functions in MCI, AD, and dementias.

Role for Physical Fitness in the Association between Age and Cognitive Function in Older Adults: A Mediation Analysis of the SABE Colombia Study

Objectives. We investigated the association between physical fitness and cognitive status. Further, we examined whether physical fitness mediates the association between cognitive functioning and aging. Design. Cross-sectional study. Setting. Urban and rural Colombian older adults. Methods. 4416 participants from the SABE study were included in the current analysis. Physical fitness was assessed with the handgrip test and the usual gait speed test. Cognitive status was evaluated through the Folstein Mini-Mental State Examination. A parallel mediation path was used to test the possible mediator role of physical fitness between aging and cognitive functioning. Results. Older adults with lower handgrip strength (HGS) were more likely to have mild-cognitive status than older adults with healthy HGS (OR = 1.53, 95% CI = 1.15; 2.02). In addition, older adults with a slower gait speed were more likely to have mild cognitive impairment (OR = 2.05, 95% CI = 1.54; 2.78). Age had an inverse relationship with cognitive function (β = −0.110, 95% CI = −0.130; −0.100) and it was also inversely associated with HGS (β = −0.003, 95% CI = −0.005; −0.002) and gait speed (β = −0.010, 95% CI = −0.011; −0.009). The indirect effects, which indicate that the effect of age on cognitive function is transmitted through mediators, showed that both gait speed (β = −0.028, 95% CI = −0.036; −0.020) and HGS (β = −0.014, 95% CI = −0.024; −0.005) were independent mediators of the detrimental effect of aging on cognitive function. Conclusions. Physical fitness mediates the effects of aging on cognitive functioning. Our findings suggest that physical activity can be a key factor to prevent cognitive deterioration during aging process.

Preventing dementia? Interventional approaches in mild cognitive impairment

Mild cognitive impairment (MCI) is defined as an intermediate state between normal cognitive aging and dementia. It describes a status of the subjective impression of cognitive decline and objectively detectible memory impairment beyond normal age-related changes. Activities of daily living are not affected. As the population ages, there is a growing need for early, proactive programs that can delay the consequences of dementia and improve the well-being of people with MCI and their caregivers. Various forms and approaches of intervention for older people with MCI have been suggested to delay cognitive decline. Pharmacological as well as non-pharmacological approaches (cognitive, physiological, nutritional supplementation, electric stimulation, psychosocial therapeutic) and multicomponent interventions have been proposed. Interventional approaches in MCI from 2009 to April 2019 concerning the cognitive performance are presented in this review.

Influence of Cardiorespiratory Fitness on Risk of Dementia and Dementia Mortality: A Systematic Review and Meta-Analysis of Prospective Cohort Studies

The purpose of this meta-analysis was to investigate the influence of cardiorespiratory fitness (CF) levels on dementia risk and dementia mortality. MEDLINE and EMBASE databases were used to search for eligible studies from January 1990 to September 2019. To be included, the study was required to be a prospective cohort study that provided CF measurements and indicated relative risk and confidence intervals for the associations between CF and dementia risk and mortality. A total of six studies were selected for this meta-analysis. Low-level CF was associated with nearly three times greater risk of dementia (2.93, 95% confidence interval [1.31, 6.57]; p < .05) compared with a high-level CF. Enhanced CF levels decreased the risk of dementia, and an increase of one metabolic equivalent of task in the CF level reduced the risk of dementia and dementia mortality. Maintaining more than 12 metabolic equivalents of task of CF level was required to substantially decrease dementia risk and dementia mortality.

Roles of β-Endorphin in Stress, Behavior, Neuroinflammation, and Brain Energy Metabolism

β-Endorphins are peptides that exert a wide variety of effects throughout the body. Produced through the cleavage pro-opiomelanocortin (POMC), β-endorphins are the primarily agonist of mu opioid receptors, which can be found throughout the body, brain, and cells of the immune system that regulate a diverse set of systems. As an agonist of the body's opioid receptors, β-endorphins are most noted for their potent analgesic effects, but they also have their involvement in reward-centric and homeostasis-restoring behaviors, among other effects. These effects have implicated the peptide in psychiatric and neurodegenerative disorders, making it a research target of interest. This review briefly summarizes the basics of endorphin function, goes over the behaviors and regulatory pathways it governs, and examines the variability of β-endorphin levels observed between normal and disease/disorder affected individuals.

Understanding the Neurophysiological and Molecular Mechanisms of Exercise-Induced Neuroplasticity in Cortical and Descending Motor Pathways: Where Do We Stand?

Exercise is a promising, cost-effective intervention to augment successful aging and neurorehabilitation. Decline of gray and white matter accompanies physiological aging and contributes to motor deficits in older adults. Exercise is believed to reduce atrophy within the motor system and induce neuroplasticity which, in turn, helps preserve motor function during aging and promote re-learning of motor skills, for example after stroke. To fully exploit the benefits of exercise, it is crucial to gain a greater understanding of the neurophysiological and molecular mechanisms underlying exercise-induced brain changes that prime neuroplasticity and thus contribute to postponing, slowing, and ameliorating age- and disease-related impairments in motor function. This knowledge will allow us to develop more effective, personalized exercise protocols that meet individual needs, thereby increasing the utility of exercise strategies in clinical and non-clinical settings. Here, we review findings from studies that investigated neurophysiological and molecular changes associated with acute or long-term exercise in healthy, young adults and in healthy, postmenopausal women.

Physical Activity for Executive Function and Activities of Daily Living in AD Patients: A Systematic Review and Meta-Analysis

Objectives: The present study aimed to systematically analyze the effects of physical activity on executive function, working memory, cognitive flexibility, and activities of daily living (ADLs) in Alzheimer's disease (AD) patients and to provide a scientific evidence-based exercise prescription.

Methods: Both Chinese and English databases (PubMed, Web of Science, the Cochrane Library, EMBASE, VIP Database for Chinese Technical Periodicals, China National Knowledge Infrastructure, and Wanfang) were used as sources of data to search for randomized controlled trials (RCTs) published between January 1980 and December 2019 relating to the effects of physical activity on executive function, working memory, cognitive flexibility, and ADL issues in AD patients. Sixteen eligible RCTs were ultimately included in the meta-analysis.

Results: Physical activity had significant benefits on executive function [standard mean difference (SMD) = 0.42, 95% confidence interval (CI) 0.22–0.62, p < 0.05], working memory (SMD = 0.28, 95% CI 0.11–0.45, p < 0.05), cognitive flexibility (SMD = 0.23, 95% CI −0.02 to 0.47, p < 0.01), and ADLs (SMD = 0.68, 95% CI 0.19–1.16, p < 0.05) among AD patients. Subgroup analysis indicated that, for executive function issues, more than 60 min per session for 16 weeks of moderate-to-high-intensity dual-task exercises or multimodal exercise had a greater effect on AD patients. For working memory and cognitive flexibility issues, 60–90 min of moderate-intensity dual-task exercises 1–4 times/week was more effective. For ADL issues, 30–90 min of multimodal exercise at 60–79% of maximal heart rate (MHR) 3–4 times/week had a greater effect on AD patients.

Conclusions: Physical activity was found to lead to significant improvements in executive function, working memory, cognitive flexibility, and ADLs in AD patients and can be used as an effective method for clinical exercise intervention in these patients. However, more objective, scientific, and effective RCTs are needed to confirm this conclusion.

Comparative Cognitive Effects of Choreographed Exercise and Multimodal Physical Therapy in Older Adults with Amnestic Mild Cognitive Impairment: Randomized Clinical Trial

Background:

Recent research on mild cognitive impairment (MCI) has primarily focused on searching for measures to prevent or delay the progression of MCI to dementia. Physical exercise has shown to be effective in the prevention of age-related cognitive decline in elderly adults with MCI. However, the most effective type and dose of exercise for the improvement of cognition are yet to be determined.

Objective:

To compare the cognitive effects of choreographed exercise (Choreography group) with a multimodal physical therapy program (Physical Therapy group) in elderly adults with amnestic MCI, a population with an increased risk of developing dementia.

Methods:

We conducted a randomized clinical trial with two parallel groups under allocation concealment and assessor blinding. Participants were allocated into Choreography or Physical Therapy group and performed exercises twice per week in 60-minute sessions during 12 weeks.

Results:

Thirty-six participants with amnestic MCI, ages 65 to 85, were assessed at baseline and after 12 weeks of intervention, by comprehensive validated neuropsychological and physical assessments. A Repeated measures General Lineal Model showed statistically significant differences in cognitive and physical outcomes. Both groups significantly improved in visual delayed recall. The Choreography group exhibited significantly more benefits on verbal recognition memory than the Physical Therapy group.

Conclusion:

Greater cognitive benefits were achieved in the choreographic intervention than in the multimodal physical therapy, mainly in those functions more related to the risk of conversion to dementia. Additional studies are needed to confirm whether the observed effects are related to delayed onset of Alzheimer’s disease in elderly adults with amnestic MCI.

Relationship Between Step Counts and Cerebral Small Vessel Disease in Japanese Men

BACKGROUND AND PURPOSE

Cerebral small vessel disease (CSVD) is a common subclinical feature of the aging brain. Steps per day may contribute to its prevention. We herein investigated the association between step counts and CSVD in a healthy Japanese male population.

METHODS

We analyzed data from 680 men who were free of stroke and participated in this observational study. Seven-day step counts were assessed at baseline (2006-2008) using a pedometer. CSVD was assessed at follow-ups (2012-2015) based on deep and subcortical white matter hyperintensities (WMHs), periventricular hyperintensities, lacunar infarcts, and cerebral microbleeds on magnetic resonance imaging. Using a logistic regression analysis, we computed the adjusted odds ratios, with 95% CIs, of prevalent CSVD according to quartiles of step counts (reference: Q1). We also investigated the association between step counts and WMH volumes using a quantile regression.

RESULTS

Steps per day were significantly associated with lower odds ratios, with the lowest at Q3 (8175-10 614 steps/day), of higher (versus low or no burden) deep and subcortical WMHs (odds ratio, 0.52 [95% CI, 0.30-0.89]), periventricular hyperintensities (0.50 [95% CI, 0.29-0.86]), and lacunar infarcts (0.52 [95% CI, 0.30-0.91]) compared with Q1 (≤6060 steps/day) but not cerebral microbleeds. An inverse linear association was observed between step counts and WMH volumes. These associations were independent of age and smoking and drinking status and remained consistent when adjusted for vascular risk factors.

CONCLUSIONS

We found a J-shaped relationship between step counts and prevalent CSVD in healthy Japanese men, with the lowest risk being observed among participants with ≈8000 to 10 000 steps/day. Higher steps were also associated with lower WMH volumes.

Current Cognition Tests, Potential Virtual Reality Applications, and Serious Games in Cognitive Assessment and Non-Pharmacological Therapy for Neurocognitive Disorders

As the global population ages, the incidence of major neurocognitive disorders (major NCDs), such as the most common geriatric major NCD, Alzheimer's disease (AD), has grown. Thus, the need for more definitive cognitive assessment or even effective non-pharmacological intervention for age-related NCDs is becoming more and more pressing given that no definitive diagnostics or efficacious therapeutics are currently unavailable for them. We evaluate the current state of the art of cognitive assessment for major NCDs, and then briefly glance ahead at potential application of virtual reality (VR) technologies in major NCD assessment and in cognition training of visuospatial reasoning in a 3D environment, as well as in the alleviation of depression and other symptoms of cognitive disorders. We believe that VR-based technologies have tremendous potentials in cognitive assessment and non-pharmacological therapy for major NCDs.

The Reversal of Memory Deficits in an Alzheimer's Disease Model Using Physical and Cognitive Exercise

Alzheimer’s disease (AD) is the leading cause of dementia in the world, accounting for 50–75% of cases. Currently, there is limited treatment for AD. The current pharmacological therapy minimizes symptom progression but does not reverse brain damage. Studies focused on nonpharmacological treatment for AD have been developed to act on brain plasticity and minimize the neurotoxicity caused by the amyloid-beta (Aβ) peptide. Using a neurotoxicity model induced by Aβ in rats, the present study shows that physical (PE) and cognitive exercise (CE) reverse recognition memory deficits (with a prominent effect of long-term object recognition memory), decrease hippocampal lipid peroxidation, restore the acetylcholinesterase activity altered by Aβ neurotoxicity, and seems to reverse, at least partially, hippocampal tissue disorganization.

The effectiveness of dance interventions on cognition in patients with mild cognitive impairment: A meta-analysis of randomized controlled trials

This meta-analysis of randomized controlled trials (published or unpublished RCTs in English) examined the effectiveness of dance interventions compared to waitlist/active controls on cognitive functions in patients with mild cognitive impairment (MCI). Literature search was conducted on MEDLINE, EMBASE, CINAHL and related databases through 3 August 2019. Risk of bias was assessed with the PEDro scale regarding randomization, allocation concealment, group comparability, blinding, attrition and selective reporting. Five included RCTs (N = 358) used Latin, ballroom and aerobic dances (frequency: 1-3 session/week; intensity: light to moderate; time: 25-60 min/session; type: aerobic). Results show that dance interventions improve global cognition (SMD [95 % CI] = 0.48 [0.21, 0.74]), attention (SMD [95 % CI] = 0.33 [0.12, 0.54]), immediate (SMD [95 % CI] = 0.54 [0.38, 0.71]) and delayed recall (SMD [95 % CI] = 0.33 [0.01, 0.64]), and visuospatial ability (SMD [95 % CI] = 0.16 [0.01, 0.32]). Study limitations include a small number of RCTs and high heterogeneity in some cognitive domains. In summary, dance interventions improve some cognitive domains in MCI. (PROSPERO registration: CRD42019145418).

Exercise and dementia prevention

Ageing, genetic, medical and lifestyle factors contribute to the risk of Alzheimer’s disease and other dementias. Around a third of dementia cases are attributable to modifiable risk factors such as physical inactivity, smoking and hypertension. With the rising prevalence and lack of neuroprotective drugs, there is renewed focus on dementia prevention strategies across the lifespan. Neurologists encounter many people with risk factors for dementia and are frequently asked whether lifestyle changes may help. Exercise has emerged as a key intervention for influencing cognition positively, including reducing the risk of age-related cognitive decline and dementia. This article focuses on the current evidence for physical inactivity as a modifiable dementia risk factor and aims to support neurologists when discussing risk reduction.

Pathways of Prevention: A Scoping Review of Dietary and Exercise Interventions for Neurocognition

Alzheimer's disease and related dementias (ADRD) represent an increasingly urgent public health concern, with an increasing number of baby boomers now at risk. Due to a lack of efficacious therapies among symptomatic older adults, an increasing emphasis has been placed on preventive measures that can curb or even prevent ADRD development among middle-aged adults. Lifestyle modification using aerobic exercise and dietary modification represents one of the primary treatment modalities used to mitigate ADRD risk, with an increasing number of trials demonstrating that exercise and dietary change, individually and together, improve neurocognitive performance among middle-aged and older adults. Despite several optimistic findings, examination of treatment changes across lifestyle interventions reveals a variable pattern of improvements, with large individual differences across trials. The present review attempts to synthesize available literature linking lifestyle modification to neurocognitive changes, outline putative mechanisms of treatment improvement, and discuss discrepant trial findings. In addition, previous mechanistic assumptions linking lifestyle to neurocognition are discussed, with a focus on potential solutions to improve our understanding of individual neurocognitive differences in response to lifestyle modification. Specific recommendations include integration of contemporary causal inference approaches for analyzing parallel mechanistic pathways and treatment-exposure interactions. Methodological recommendations include trial multiphase optimization strategy (MOST) design approaches that leverage individual differences for improved treatment outcomes.

An Investigation of Limbs Exercise as a Treatment in Improving the Psychomotor Speed in Older Adults with Mild Cognitive Impairment

Objectives: This study investigated the effects of therapeutic structured limb exercises intended to improve psychomotor speed in older adults with mild cognitive impairment (MCI). Methods: Forty-four patients with mild cognitive impairment who met the inclusion criteria were selected and assigned randomly to either an experimental group (22 patients) or a control group (22 patients). The numbers of participants were selected based on the calculated sample effect size (N = 38). The study involved a 10-week intervention, in which participants completed structured limb exercises during 60-min training sessions delivered three times per week. Forty-one subjects completed the experimental programme. Scores in the Finger Tapping Test (FTT), Purdue Pegboard Test (PPT) and Montreal Cognitive Assessment (MoCA), along with electroencephalography (EEG) data, were collected before, during and after the intervention. The experimental and control groups were compared using repeated measures analysis of variance. Results: The patients with MCI in the experimental group achieved significantly improved scores in the FTT, the PPT and all dimensions of the MoCA. Moreover, these patients exhibited significant increases in the alpha and beta EEG wave power values in all brain areas of MCI patients, indicating that limb exercise training positively influenced their brain functions. Conclusions: The results conclude that a structured therapeutic limb exercise intervention can effectively improve psychomotor speed in patients with MCI and mitigate declines in cognitive function. This training intervention appears to be effective as a treatment for community-dwelling patients with MCI.

Mediators of a Physical Activity Intervention on Cognition in Breast Cancer Survivors: Evidence From a Randomized Controlled Trial

Background

Emerging research suggests that increasing physical activity can help improve cognition among breast cancer survivors. However, little is known about the mechanism through which physical activity impacts cancer survivors’ cognition.

Objective

The objective of this secondary analysis examined physical and psychological function potentially linking physical activity with changes in cognition among breast cancer survivors in a randomized controlled trial where the exercise arm had greater improvements in cognition than the control arm.

Methods

A total of 87 sedentary breast cancer survivors were randomized to a 12-week physical activity intervention (n=43) or control condition (n=44). Objectively measured processing speed (National Institutes of Health Toolbox Oral Symbol Digit), self-reported cognition (patient-reported outcomes measurement information system [PROMIS] cognitive abilities), PROMIS measures of physical and psychological function (depression, anxiety, fatigue, and physical functioning), and plasma biomarkers (brain-derived neurotrophic factor, homeostatic model assessment 2 of insulin resistance, and C-reactive protein [CRP]) were collected at baseline and 12 weeks. Linear mixed-effects models tested intervention effects on changes in physical and psychological function variables and biomarkers. Bootstrapping was used to assess mediation. Exploratory analyses examined self-reported cognitive abilities and processing speed as mediators of the intervention effect on physical functioning.

Results

Participants in the exercise arm had significantly greater improvements in physical functioning (beta=1.23; 95% CI 2.42 to 0.03; P=.049) and reductions in anxiety (beta=−1.50; 95% CI −0.07 to −2.94; P=.04) than those in the control arm. Anxiety significantly mediated the intervention effect on cognitive abilities (bootstrap 95% CI −1.96 to −0.06), whereas physical functioning did not (bootstrap 95% CI −1.12 to 0.10). Neither anxiety (bootstrap 95% CI −1.18 to 0.74) nor physical functioning (bootstrap 95% CI −2.34 to 0.15) mediated the intervention effect on processing speed. Of the biomarkers, only CRP had greater changes in the exercise arm than the control arm (beta=.253; 95% CI −0.04 to 0.57; P=.09), but CRP was not associated with cognition; therefore, none of the biomarker measures mediated the intervention effect on cognition. Neither cognitive abilities (bootstrap 95% CI −0.06 to 0.68) nor processing speed (bootstrap 95% CI −0.15 to 0.63) mediated the intervention effect on physical function.

Conclusions

Physical activity interventions may improve self-reported cognition by decreasing anxiety. If supported by larger studies, reducing anxiety may be an important target for improving self-reported cognition among cancer survivors.

Trial Registration

ClinicalTrials.gov NCT02332876; https://clinicaltrials.gov/ct2/show/NCT02332876

Exercise, spinogenesis and cognitive functions

Exercise training improves mental and cognitive functions by enhancing neurogenesis and neuroprotection. Recent studies suggest the facilitation of spinogenesis across different brain regions including hippocampus and cerebral cortex by physical activity. In this article we will summarize major findings for exercise effects on synaptogenesis and spinogenesis, in order to provide mechanisms for exercise intervention of both psychiatric diseases and neurodegenerative disorders. We will also revisit major findings for molecular mechanism governing exercise-related spinogenesis, and will discuss the screening for novel factors, or exerkines, whose levels are correlated with endurance training and affect neural plasticity. We believe that further studies focusing on the molecular mechanism of exercise-mediate spinogenesis should benefit the optimization of exercise therapy in clinics and the evaluation of treatment efficiency using specific biomarkers.

Microglia Express Insulin-Like Growth Factor-1 in the Hippocampus of Aged APPswe/PS1ΔE9 Transgenic Mice

Insulin-like growth factor-1 (IGF-1) is a pleiotropic molecule with neurotrophic and immunomodulatory functions. Knowing the capacity of chronically activated microglia to produce IGF-1 may therefore show essential to promote beneficial microglial functions in Alzheimer's disease (AD). Here, we investigated the expression of IGF-1 mRNA and IGF-1 along with the expression of tumor necrosis factor (TNF) mRNA, and the amyloid-β (Aβ) plaque load in the hippocampus of 3- to 24-month-old APPswe/PS1ΔE9 transgenic (Tg) and wild-type (WT) mice. As IGF-1, in particular, is implicated in neurogenesis we also monitored the proliferation of cells in the subgranular zone (sgz) of the dentate gyrus. We found that the Aβ plaque load reached its maximum in aged 21- and 24-month-old APPswe/PS1ΔE9 Tg mice, and that microglial reactivity and hippocampal IGF-1 and TNF mRNA levels were significantly elevated in aged APPswe/PS1ΔE9 Tg mice. The sgz cell proliferation decreased with age, regardless of genotype and increased IGF-1/TNF mRNA levels. Interestingly, IGF-1 mRNA was expressed in subsets of sgz cells, likely neuroblasts, and neurons in both genotypes, regardless of age, as well as in glial-like cells. By double in situ hybridization these were shown to be IGF1 mRNA+ CD11b mRNA+ cells, i.e., IGF-1 mRNA-expressing microglia. Quantification showed a 2-fold increase in the number of microglia and IGF-1 mRNA-expressing microglia in the molecular layer of the dentate gyrus in aged APPswe/PS1ΔE9 Tg mice. Double-immunofluorescence showed that IGF-1 was expressed in a subset of Aβ plaque-associated CD11b+ microglia and in several subsets of neurons. Exposure of primary murine microglia and BV2 cells to Aβ42 did not affect IGF-1 mRNA expression. IGF-1 mRNA levels remained constant in WT mice with aging, unlike TNF mRNA levels which increased with aging. In conclusion, our results suggest that the increased IGF-1 mRNA levels can be ascribed to a larger number of IGF-1 mRNA-expressing microglia in the aged APPswe/PS1ΔE9 Tg mice. The finding that subsets of microglia retain the capacity to express IGF-1 mRNA and IGF-1 in the aged APPswe/PS1ΔE9 Tg mice is encouraging, considering the beneficial therapeutic potential of modulating microglial production of IGF-1 in AD.

Effects of 12-Week Resistance Exercise on Electroencephalogram Patterns and Cognitive Function in the Elderly With Mild Cognitive Impairment: A Randomized Controlled Trial

OBJECTIVE

To investigate the effects of a 12-week resistance exercise program with an elastic band on electroencephalogram (EEG) patterns and cognitive function in elderly patients with mild cognitive impairment (MCI).

DESIGN

Randomized controlled trial.

SETTING

Community center.

PARTICIPANTS

Twenty-two subjects with MCI and 25 healthy volunteer subjects were randomly assigned to 1 of 4 groups: subjects with MCI who undertook the exercise program (MCI-EX; n = 10), an MCI control group (MCI-Con; n = 12), a healthy volunteer exercise group (NG-EX; n = 12), and a healthy volunteer control group (NG-Con; n = 13).

INTERVENTION

The exercise group engaged in a 15-repetition maximum (15RM; 65% of 1RM) resistance exercise program for 12 weeks.

MAIN OUTCOME MEASURES

Electroencephalograms, neuropsychological tests, and Senior Fitness Test.

RESULTS

The 12-week 15RM (65% of 1RM) resistance exercise program significantly improved variables related to the physical fitness of the elderly subjects. Furthermore, for the EEG test, the MCI and NG groups showed significant differences at baseline in relative beta waves on electrodes Fp1 (P < 0.05) and F3 (P < 0.05), as well as in relative beta2 waves on F3 (P < 0.05). In addition, after the 12-week exercise intervention, differences in a region that benefits from exercise were observed between (1) the MCI-EX group in the relative theta power on F3 (P < 0.05) and the relative alpha power on T3 (P < 0.05) and in (2) the NG-EX group in the relative theta power on P3 (P < 0.05) and P4 (P < 0.01). In addition, only the score of the digit span backward in the MCI-EX group changed significantly (P < 0.05).

CONCLUSIONS

The 12-week resistance exercise with an elastic band had a positive effect on EEG patterns in elderly subjects with MCI, along with providing physical benefits and slight changes in cognitive function in MCI-EX group.

SIGNIFICANCE

A 15RM resistance exercise program can be an effective treatment for delaying cognitive decline and improving physical fitness.

Chronic physical exercise increases a neurogenesis marker within hippocampus

Background:Aerobic and anaerobic physical exercises conducted in both acute and chronic are really essential in keeping the body especially brain healthy. Physical exercise plays an important role in molecular system and is beneficial for the brain by enhancing neurogenesis which is mediated by the increase of BDNF level. This study aimed to evaluate the effect of physical exercise to the BDNF level of hippocampus tissues in Wistar rats.Methods: Thirty male rats were divided into five groups i.e. control group, acute aerobic physical exercise group, acute anaerobic physical exercise group, chronic aerobic physical exercise group, and chronic anaerobic physical exercise group. Physical exercises were conducted on animal treadmill. The level of hippocampus BDNF was determined using ELISA. The data were analyzed using independent t-test.Results: BDNF average levels of chronic aerobic and anaerobic physical exercises were higher than those of acute ones (152.86±1.62 pg/ml and 122.22±1.53 pg/ml vs 59.38±6.10 pg/ml and 54.05±3.35 pg/ml). There were significant differences in the BDNF average levels of hippocampus tissues between aerobic and anaerobic groups, in both acute and chronic exercise.Conclusion: The chronic physical exercises, both aerobic or anaerobic, are increasing higher the level of BDNF in brain tissue.

The Enhanced Interactive Physical and Cognitive Exercise System (iPACESTM v2.0): Pilot Clinical Trial of an In-Home iPad-Based Neuro-Exergame for Mild Cognitive Impairment (MCI)

Given increasing longevity worldwide, older adults and caregivers are seeking ways to curb cognitive decline especially for those with mild cognitive impairment (MCI, now mild neurocognitive disorder, mNCD, Diagnostic and Statistical Manual of Mental Disorders, 5th ed. (DSM-V). This quasi-experimental, within-subjects pilot clinical trial was designed to replicate and extend the study of cognitive benefits for MCI by improving upon our prior interactive Physical and Cognitive Exercise Study (iPACESTM v1.0) by increasing the usability of the neuro-exergame and exploring possible underlying neurobiological mechanisms. Older adults were enrolled in a three-month, in-home trial of a portable neuro-exergame (iPACES™ v2.0) where participants pedaled and steered along a virtual bike path (Memory Lane™). Neuropsychological function was assessed at baseline after component familiarization intervals (e.g., two weeks of exercise-only, game-only, etc.) and after three months of interactive neuro-exergame intervention. Fourteen participants were enrolled in the study and seven completed the final evaluation. Intent-to-treat analyses were conducted with imputed missing data (total n = 14). Significant improvement in executive function (Stroop) was found (d = 0.68, p = 0.02) only. Changes in salivary biomarkers (cortisol and insulin-like growth factor 1; IGF-1) were significantly associated with improved cognition. Further research is needed, but pilot data suggest that a portable in-home neuro-exergame may be an additional, practical tool to fight back against cognitive decline and dementia.

Klotho protein in neurodegenerative disorders

The Klotho protein is a recently discovered protein and its overexpression is associated with life extension. Klotho deficiency or silencing of the Klotho gene in mice leads to an accelerated aging and short life, whereas overexpression of Klotho in mice extends lifespan. Klotho participates in many metabolic pathways and is highly expressed in the kidneys, the choroid plexus and neurons. It plays a key role in the calcium-phosphate metabolism, remyelination, and cognitive processes. The present paper is a short review of the literature on the role of Klotho in neurodegenerative disorders, with special attention paid to multiple sclerosis. The neuroprotective function of Klotho is also reported. It is also important to consider potential clinical applications of Klotho that might be useful in the treatment of many diseases.

Physical exercise, IGF-1 and cognition A systematic review of experimental studies in the elderly

One of hypothetical mechanisms related to cognition is exercise-induced IGF-1.

Randomized controlled trial of increasing physical activity on objectively measured and self-reported cognitive functioning among breast cancer survivors: The memory & motion study

BACKGROUND

Increasing physical activity can improve cognition in healthy and cognitively impaired adults; however, the benefits for cancer survivors are unknown. The current study examined a 12-week physical activity intervention, compared with a control condition, on objective and self-reported cognition among breast cancer survivors.

METHODS

Sedentary breast cancer survivors were randomized to an exercise arm (n = 43) or a control arm (n = 44). At baseline and at 12 weeks, objective cognition was measured with the National Institutes of Health Cognitive Toolbox, and self-reported cognition using the Patient-Reported Outcomes Measurement Information System scales. Linear mixed-effects regression models tested intervention effects for changes in cognition scores.

RESULTS

On average, participants (n = 87) were aged 57 years (standard deviation, 10.4 years) and were 2.5 years (standard deviation, 1.3 years) post surgery. Scores on the Oral Symbol Digit subscale (a measure of processing speed) evidenced differential improvement in the exercise arm versus the control arm (b = 2.01; P < .05). The between-group differences in improvement on self-reported cognition were not statistically significant but were suggestive of potential group differences. Time since surgery moderated the correlation, and participants who were ≤2 years post surgery had a significantly greater improvement in Oral Symbol Digit score (exercise vs control (b = 4.00; P < .01), but no significant improvement was observed in patients who were >2 years postsurgery (b = -1.19; P = .40). A significant dose response was observed with greater increased physical activity associated with objective and self-reported cognition in the exercise arm.

CONCLUSIONS

The exercise intervention significantly improved processing speed, but only among those who had been diagnosed with breast cancer within the past 2 years. Slowed processing speed can have substantial implications for independent functioning, supporting the potential importance of early implementation of an exercise intervention among patients with breast cancer. Cancer 2018;124:192-202. © 2017 American Cancer Society.

The Effects of a Multicomponent Dyadic Intervention With Physical Exercise on the Cognitive Functioning of People With Dementia: A Randomized Controlled Trial

The objective was to evaluate the effects of a multicomponent dyadic intervention on the cognitive functioning of people with dementia living at home in a randomized controlled trial. People with dementia and their family caregivers (n = 111) were randomly assigned to 8 home-based sessions including physical exercise and support or a minimal intervention consisting of monthly written information bulletins and monthly phone calls. Memory, executive functioning (EF), and attention were assessed at baseline, and after 3 (postmeasurement) and 6 months (follow-up). Data were analyzed by using generalized estimating equations (GEE). A small, significant effect was found on attention. No effects were found on memory and EF. Finding only a small significant effect might be explained by the ineffectiveness of the intervention, but also by moderate treatment adherence or a lack of room for improvement because half of the people with dementia were already receiving care in a day care facility.

Biological effects of dosing aerobic exercise and neuromuscular electrical stimulation in rats

Aerobic exercise (AE) and non-aerobic neuromuscular electric stimulation (NMES) are common interventions used in physical therapy. We explored the dose-dependency (low, medium, high) of these interventions on biochemical factors, such as brain derived neurotrophic growth factor (BDNF), vascular endothelial growth factor-A (VEGF-A), insulin-like growth factor-1 (IGF-1) and Klotho, in the blood and brain of normal rats, as well as a treadmill-based maximum capacity test (MCT). A medium dose of AE produced the most improvement in MCT with dose-dependent changes in Klotho in the blood. A dose-dependent increase of BDNF was evident following completion of an NMES protocol, but there was no improvement in MCT performance. Gene expression in the hippocampus was increased after both AE and NMES, with IGF-1 being a signaling molecule that correlated with MCT performance in the AE conditions, but also highly correlated with VEGF-A and Klotho. Blood Klotho levels can serve as a biomarker of therapeutic dosing of AE, whereas IGF-1 is a key molecule coupled to gene expression of other molecules in the hippocampus. This approach provides a translatable paradigm to investigate the mode and mechanism of action of interventions employed in physical therapy that can improve our understanding of how these factors change under pathological conditions.

The Moderating Role of Insulin-Like Growth Factor 1 in the Relationship Between Cognitive and Aerobic Endurance Change

BACKGROUND

Improvements in cognition often accompany fitness improvements in older adults, and research suggests insulin-like growth factor 1 (IGF-1) may influence this association. No prior work has examined this in mild cognitive impairment (MCI). We predicted that IGF-1 would moderate the relationship between cognition and aerobic endurance improvement, such that greater baseline IGF-1 would accompany a stronger relationship between cognition and aerobic endurance change.

METHOD

Twenty-seven individuals with MCI completed assessments of aerobic endurance (2-minute step test [2MST]) and global cognition (Modified Mini-Mental State [3MS]) before and after a 6-month period of twice-weekly exercise. Serum IGF-1 levels were assessed at baseline via fasted blood draw. The Johnson-Neyman technique determined whether baseline IGF-1 levels moderated the relationship between changes in aerobic endurance (Δ2MST) and cognition (Δ3MS).

RESULTS

A significant interaction was found; however, Δ2MST was inversely associated with Δ3MS in individuals with above-average serum IGF-1 levels; this relationship was strengthened as IGF-1 increased and was not seen when IGF-1 was below average.

CONCLUSION

The relationship between cognitive and aerobic endurance change varies as a function of IGF-1 in persons with MCI. Additional work is needed to clarify the mechanisms of these findings.