The beneficial effects of physical exercise in the brain and related pathophysiological mechanisms in neurodegenerative diseases

Strengthening the Case for Cluster Set Resistance Training in Aged and Clinical Settings: Emerging Evidence, Proposed Benefits and Suggestions

Resistance training (RT) is a fundamental component of exercise prescription aimed at improving overall health and function. RT techniques such as cluster set (CS) configurations, characterized by additional short intra-set or inter-repetition rest intervals, have been shown to maintain acute muscular force, velocity, and 'power' outputs across a RT session, and facilitate positive longer-term neuromuscular adaptations. However, to date CS have mainly been explored from a human performance perspective despite potential for application in health and clinical exercise settings. Therefore, this current opinion piece aims to highlight emerging evidence and provide a rationale for why CS may be an advantageous RT technique for older adults, and across several neurological, neuromuscular, cardiovascular and pulmonary settings. Specifically, CS may minimize acute fatigue and adverse physiologic responses, improve patient tolerance of RT and promote functional adaptations (i.e., force, velocity, and power). Moreover, we propose that CS may be a particularly useful exercise rehabilitation technique where injury or illness, persistent fatigue, weakness and dysfunction exist. We further suggest that CS offer an alternative RT strategy that can be easily implemented alongside existing exercise/rehabilitation programs requiring no extra cost, minimal upskilling and/or time commitment for the patient and professional. In light of the emerging evidence and likely efficacy in clinical exercise practice, future research should move toward further direct investigation of CS-based RT in a variety of adverse health conditions and across the lifespan given the already demonstrated benefits in healthy populations.

Physical exercise modulates the astrocytes polarization, promotes myelin debris clearance and remyelination in chronic cerebral hypoperfusion rats

AIMS

White matter damage is the main pathological feature of chronic cerebral hypoperfusion (CCH) and glial activation is crucial in this process. Physical exercise has protective effects on CCH, but the mechanism is unclear. Therefore, this study focuses on investigating the influence of physical exercise on activated astrocytes polarization and its role in CCH.

MAIN METHODS

Rats were given wheel running 48 h after 2VO (2 vessel occlusion) surgery. The cognitive function was evaluated by Morris water maze and novel object recognition test. Inflammatory cytokines expressions were detected by ELISA. Astrocytes polarization was analyzed by immunofluorescence. Myelin debris clearance and remyelination were detected by immunofluorescence and transmission electron microscopy.

KEY FINDINGS

Astrocytes were activated and mainly switched to A1 phenotype in rats 2 and 3 months after 2VO. Myelin debris deposition and limited remyelination can be observed at the corresponding time. Whereas physical exercise can improve the cognitive function of 2VO rats, downregulate the expression of inflammatory factors IL-1α, C1q and TNF, upregulate the release of TGFβ, and promote activated astrocytes transformation from A1 to A2 phenotype. In addition, it can also enhance myelin debris removal and remyelination.

SIGNIFICANCE

These findings suggest that the benefits of physical exercise on white matter repair and cognition improvement may be related to its regulation of astrocytes polarization, which contributes to myelin debris clearance and effective remyelination in CCH.

A Critical Systematic Review of Current Evidence on the Effects of Physical Exercise on Whole/Regional Grey Matter Brain Volume in Populations at Risk of Neurodegeneration

BACKGROUND

Despite the intriguing potential of physical exercise being able to preserve or even restore brain volume (grey matter volume in particular)-a tissue essential for both cognitive and physical function-no reviews have so far synthesized the existing knowledge from randomized controlled trials investigating exercise-induced changes of the brain's grey matter volume in populations at risk of neurodegeneration. Our objective was to critically review the existing evidence regarding this topic.

METHODS

A systematic search was carried out in MEDLINE and EMBASE databases primo April 2020, to identify randomized controlled trials evaluating the effects of aerobic training, resistance training or concurrent training on brain grey volume changes (by MRI) in adult clinical or healthy elderly populations.

RESULTS

A total of 20 articles (from 19 RCTs) evaluating 3-12 months of aerobic, resistance, or concurrent training were identified and included, involving a total of 1662 participants (populations: healthy older adults, older adults with mild cognitive impairment or Alzheimer's disease, adults with schizophrenia or multiple sclerosis or major depression). While few studies indicated a positive effect-although modest-of physical exercise on certain regions of brain grey matter volume, the majority of study findings were neutral (i.e., no effects/small effect sizes) and quite divergent across populations. Meta-analyses showed that different exercise modalities failed to elicit any substantial effects on whole brain grey volume and hippocampus volume, although with rather large confidence interval width (i.e., variability).

CONCLUSION

Altogether, the current evidence on the effects of physical exercise on whole/regional grey matter brain volume appear sparse and inconclusive, and does not support that physical exercise is as potent as previously proposed when it comes to affecting brain grey matter volume.

Molecular Mechanisms Underlying the Beneficial Effects of Exercise on Brain Function and Neurological Disorders

As life expectancy has increased, particularly in developed countries, due to medical advances and increased prosperity, age-related neurological diseases and mental health disorders have become more prevalent health issues, reducing the well-being and quality of life of sufferers and their families. In recent decades, due to reduced work-related levels of physical activity, and key research insights, prescribing adequate exercise has become an innovative strategy to prevent or delay the onset of these pathologies and has been demonstrated to have therapeutic benefits when used as a sole or combination treatment. Recent evidence suggests that the beneficial effects of exercise on the brain are related to several underlying mechanisms related to muscle–brain, liver–brain and gut–brain crosstalk. Therefore, this review aims to summarize the most relevant current knowledge of the impact of exercise on mood disorders and neurodegenerative diseases, and to highlight the established and potential underlying mechanisms involved in exercise–brain communication and their benefits for physiology and brain function.

Physical Exercise and Alzheimer's Disease: Effects on Pathophysiological Molecular Pathways of the Disease

Alzheimer’s disease (AD), the most common form of neurodegenerative dementia in adults worldwide, is a multifactorial and heterogeneous disorder characterized by the interaction of genetic and epigenetic factors and the dysregulation of numerous intracellular signaling and cellular/molecular pathways. The introduction of the systems biology framework is revolutionizing the study of complex diseases by allowing the identification and integration of cellular/molecular pathways and networks of interaction. Here, we reviewed the relationship between physical activity and the next pathophysiological processes involved in the risk of developing AD, based on some crucial molecular pathways and biological process dysregulated in AD: (1) Immune system and inflammation; (2) Endothelial function and cerebrovascular insufficiency; (3) Apoptosis and cell death; (4) Intercellular communication; (5) Metabolism, oxidative stress and neurotoxicity; (6) DNA damage and repair; (7) Cytoskeleton and membrane proteins; (8) Synaptic plasticity. Moreover, we highlighted the increasingly relevant role played by advanced neuroimaging technologies, including structural/functional magnetic resonance imaging, diffusion tensor imaging, and arterial spin labelling, in exploring the link between AD and physical exercise. Regular physical exercise seems to have a protective effect against AD by inhibiting different pathophysiological molecular pathways implicated in AD.

Staying Strong Toolbox: Co-design of a physical activity and lifestyle program for Aboriginal families with Machado-Joseph disease in the Top End of Australia

Physical activity has positive health implications for individuals living with neurodegenerative diseases. The success of physical activity programs, particularly in culturally and linguistically diverse populations, is typically dependent on their alignment with the culture, lifestyle and environmental context of those involved. Aboriginal families living in remote communities in the Top End of Australia invited researchers to collaborate with them to co-design a physical activity and lifestyle program to keep individuals with Machado-Joseph disease (MJD) walking and moving around. The knowledge of Aboriginal families living with MJD, combined with findings from worldwide MJD research, formed the foundation for the co-design. An experience-based co-design (EBCD) approach, drawing from Indigenous and Participatory methodologies, was used. An expert panel of individuals with lived experience of MJD participated in a series of co-design phases. Prearranged and spontaneous co-design meetings were led by local community researchers within each phase. Data was collected using a culturally responsive ethnographic approach and analysed thematically. Sixteen panel members worked to develop the ‘Staying Strong Toolbox’ to cater for individuals with MJD who are ‘walking strong’; or ‘wobbly’; or ‘in a wheelchair’. Based on the ‘Staying Strong Framework’, the Toolbox was developed as a spiral bound A3 book designed to guide the user to select from a range of activities to keep them walking and moving around and to identify those activities most important to them to work on. The ‘Staying Strong Toolbox’ is a community driven, evidence based resource for a physical activity and lifestyle program for Aboriginal families with MJD. The Toolbox provides a guide for health professionals and support workers to deliver person-centred support to Aboriginal families with MJD, and that can be modified for use by other families with MJD or people with other forms of ataxia around the world.

C. elegans electrotaxis behavior is modulated by heat shock response and unfolded protein response signaling pathways

The nematode C. elegans is a leading model to investigate the mechanisms of stress-induced behavioral changes coupled with biochemical mechanisms. Our group has previously characterized C. elegans behavior using a microfluidic-based electrotaxis device, and showed that worms display directional motion in the presence of a mild electric field. In this study, we describe the effects of various forms of genetic and environmental stress on the electrotactic movement of animals. Using exposure to chemicals, such as paraquat and tunicamycin, as well as mitochondrial and endoplasmic reticulum (ER) unfolded protein response (UPR) mutants, we demonstrate that chronic stress causes abnormal movement. Additionally, we report that pqe-1 (human RNA exonuclease 1 homolog) is necessary for the maintenance of multiple stress response signaling and electrotaxis behavior of animals. Further, exposure of C. elegans to several environmental stress-inducing conditions revealed that while chronic heat and dietary restriction caused electrotaxis speed deficits due to prolonged stress, daily exercise had a beneficial effect on the animals, likely due to improved muscle health and transient activation of UPR. Overall, these data demonstrate that the electrotaxis behavior of worms is susceptible to cytosolic, mitochondrial, and ER stress, and that multiple stress response pathways contribute to its preservation in the face of stressful stimuli.

Enablers to Exercise Participation in Progressive Supranuclear Palsy: Health Professional Perspectives

Background: People living with progressive supranuclear palsy (PSP) can experience considerable difficulties with movement, walking, balance, and oculomotor control. The role of exercises and physical activities in mitigating the motor and non-motor symptoms of PSP remains uncertain. Aims: The aim of this study was to identify the perspectives and beliefs of health professionals about the benefits, enablers, and barriers to participation in exercise and physical activity across the course of disease progression of PSP. Methods: Qualitative methods, within a phenomenological framework, were used to obtain nursing and allied health professional perspectives and recommendations. Focus group and in-depth interview questions were derived from a systematic review on exercise for PSP. Expert opinions also guided the interviews, which were audio-recorded, transcribed verbatim, and de-identified. Two researchers independently conducted a thematic analysis. Results: Nineteen health professionals participated from the disciplines of nursing, physiotherapy, occupational therapy, and speech pathology. Four main themes emerged: (i) exercise and physical activities are important for living well with PSP; (ii) provision of information about the benefits of exercise and physical activities facilitates uptake; (iii) interdisciplinary teams work together to improve outcomes; and (iv) care partners can assist with the implementation of exercise and physical activities. Conclusion: Health professionals advocated physical therapies for people living with PSP. The expectation is that structured exercises and physical activities can help to optimize health and well-being, enabling people to continue to participate in social roles. The actual merits of such interventions must now be tested in large-scale controlled clinical trials.

Differential effects on blood and cerebrospinal fluid immune protein markers and kynurenine pathway metabolites from aerobic physical exercise in healthy subjects

Mounting evidence shows that physical exercise modulates systemic inflammation. However, its effect on cerebrospinal fluid (CSF) immune-marker profiles in man are largely unknown. We here report a study on healthy subjects (n = 27, males = 12, mean age 28.7, range 22-52) allocated to either an acute exercise setting over four consecutive days, or a training intervention over 4 weeks. Paired plasma and CSF samples collected at baseline, after 7 days of exercise abstention, and the day after completion of the exercise interventions, were analyzed for protein inflammation markers using a multiplex proximity extension assay and neurotransmitters and kynurenine pathway (KP) metabolites using liquid chromatography, respectively. Routine cell counts, and albumin, immunoglobulin G and neurofilament light chain concentrations in CSF remained unchanged in both paradigms, while several inflammatory proteins became upregulated after acute exercise. However, only changes in three CSF (vascular endothelial growth factor-A, interleukin-7 and matrix metalloproteinase-10) and 12 plasma proteins reached significance levels after adjustment for multiple comparisons and exclusion of less stable proteins. Similarly, KP metabolites only changed among participants after acute exercise, while neurotransmitter levels, except for increased CSF serine, remained stable. Both in plasma and CSF changes in KP metabolites and inflammatory proteins correlated, suggesting that these processes are functionally linked. These findings suggest that acute aerobic physical exercise affects immune markers and KP metabolites systemically and in the CSF.

Case Report: Concurrent Resistance and Aerobic Training Regulate Adiponectin Expression and Disease Severity in Multiple Sclerosis: A Case Study

Adapted exercise is an effective non-pharmacological tool to improve functional, cognitive, and psychological parameters in multiple sclerosis (MS), in association with increased quality of life (QoL) and decreased disease severity. Adipose tissue, through the production of different adipokines, is involved in regulating energy metabolism and inflammation. Adiponectin, increased in MS, circulates as oligomers of low (LMW), medium (MMW), and high molecular weight (HMW), the latter mediating the main biological effects. The aim of study was to evaluate the effects of 4 months training at moderate intensity [65% heart rate reserve (HRR)] on BMI, adiponectin, and QoL in a volunteer with secondary progressive MS. The parameters were evaluated before (T0), after 4 months training (T1), and 6 months after the end of training (T2); total serum adiponectin and its oligomeric profile were evaluated. We found a reduction in BMI (−0.9%) and FAT (−2.6%), an improvement in perceived QoL and a reduced expression of total adiponectin and HMW oligomers together with decreased MS disability level at T1 measured by EDSS. Despite the limitations of a case study, this represent a starting point to understand the influence of exercise in MS and the relationship with adiponectin expression.

Dance on the Brain: Enhancing Intra- and Inter-Brain Synchrony

Dance has traditionally been viewed from a Eurocentric perspective as a mode of self-expression that involves the human body moving through space, performed for the purposes of art, and viewed by an audience. In this Hypothesis and Theory article, we synthesize findings from anthropology, sociology, psychology, dance pedagogy, and neuroscience to propose The Synchronicity Hypothesis of Dance, which states that humans dance to enhance both intra- and inter-brain synchrony. We outline a neurocentric definition of dance, which suggests that dance involves neurobehavioral processes in seven distinct areas including sensory, motor, cognitive, social, emotional, rhythmic, and creative. We explore The Synchronicity Hypothesis of Dance through several avenues. First, we examine evolutionary theories of dance, which suggest that dance drives interpersonal coordination. Second, we examine fundamental movement patterns, which emerge throughout development and are omnipresent across cultures of the world. Third, we examine how each of the seven neurobehaviors increases intra- and inter-brain synchrony. Fourth, we examine the neuroimaging literature on dance to identify the brain regions most involved in and affected by dance. The findings presented here support our hypothesis that we engage in dance for the purpose of intrinsic reward, which as a result of dance-induced increases in neural synchrony, leads to enhanced interpersonal coordination. This hypothesis suggests that dance may be helpful to repattern oscillatory activity, leading to clinical improvements in autism spectrum disorder and other disorders with oscillatory activity impairments. Finally, we offer suggestions for future directions and discuss the idea that our consciousness can be redefined not just as an individual process but as a shared experience that we can positively influence by dancing together.

Circulating Extracellular Vesicles: The Missing Link between Physical Exercise and Depression Management?

Depression is associated with an increased risk of aging-related diseases. It is also seemingly a common psychological reaction to pandemic outbreaks with forced quarantines and lockdowns. Thus, depression represents, now more than ever, a major global health burden with therapeutic management challenges. Clinical data highlights that physical exercise is gaining momentum as a non-pharmacological intervention in depressive disorders. Although it may contribute to the reduction of systemic inflammation associated with depression, the mechanisms underlying the beneficial physical exercise effects in emotional behavior remain to be elucidated. Current investigations indicate that a rapid release of extracellular vesicles into the circulation might be the signaling mediators of systemic adaptations to physical exercise. These biological entities are now well-established intercellular communicators, playing a major role in relevant physiological and pathophysiological functions, including brain cell-cell communication. We also reviewed emerging evidence correlating depression with modified circulating extracellular vesicle surfaces and cargo signatures (e.g., microRNAs and proteins), envisioned as potential biomarkers for diagnosis, efficient disease stratification and appropriate therapeutic management. Accordingly, the clinical data summarized in the present review prompted us to hypothesize that physical exercise-related circulating extracellular vesicles contribute to its antidepressant effects, particularly through the modulation of inflammation. This review sheds light on the triad "physical exercise-extracellular vesicles-depression" and suggests new avenues in this novel emerging field.

Natural Molecules and Neuroprotection: Kynurenic Acid, Pantethine and α-Lipoic Acid

The incidence of neurodegenerative diseases has increased greatly worldwide due to the rise in life expectancy. In spite of notable development in the understanding of these disorders, there has been limited success in the development of neuroprotective agents that can slow the progression of the disease and prevent neuronal death. Some natural products and molecules are very promising neuroprotective agents because of their structural diversity and wide variety of biological activities. In addition to their neuroprotective effect, they are known for their antioxidant, anti-inflammatory and antiapoptotic effects and often serve as a starting point for drug discovery. In this review, the following natural molecules are discussed: firstly, kynurenic acid, the main neuroprotective agent formed via the kynurenine pathway of tryptophan metabolism, as it is known mainly for its role in glutamate excitotoxicity, secondly, the dietary supplement pantethine, that is many sided, well tolerated and safe, and the third molecule, α-lipoic acid is a universal antioxidant. As a conclusion, because of their beneficial properties, these molecules are potential candidates for neuroprotective therapies suitable in managing neurodegenerative diseases.

Exercise Training of Secreted Protein Acidic and Rich in Cysteine (Sparc) KO Mice Suggests That Exercise-Induced Muscle Phenotype Changes Are SPARC-Dependent

We previously identified secreted protein acidic and rich in cysteine (Sparc) as an exercise-induced gene in young and elderly individuals. Via this animal experiment, we aim to identify selected implications of SPARC mainly within the muscle in the contexts of exercise. Mice were divided into eight groups based on three variables (age, genotype and exercise): Old (O) or young (Y) × Sparc knock-out (KO) or wild-type (WT) × sedentary (Sed) or exercise (Ex). The exercised groups were trained for 12 weeks at the lactate threshold (LT) speed (including 4 weeks of adaptation period) and all mice were sacrificed afterwards. Body and selected tissues were weighed, and lactate levels in different conditions measured. Expression of skeletal muscle (SM) collagen type I alpha 1 chain (COL1A1) and mitochondrially encoded cytochrome c oxidase I (MT-CO1) in addition to SM strength (grip power) were also measured. Ageing increased the body and white adipose tissue (WAT) weights but decreased SM weight percentage (to body weight) and MT-CO1 expression (in WT). Exercise increased SM COL1A1 in WT mice and MT-CO1 expression, as well as weight percentage of the tibialis anterior muscle, and decreased WAT weight (trend). Compared to WT mice, Sparc KO mice had lower body, muscle and WAT weights, with a decrease in SM MT-CO1 and COL1A1 expression with no genotype effect on lactate levels in all our blood lactate measures. Sparc KO effects on body composition, adiposity and metabolic patterns are toward a reduced WAT and body weight, but with a negative metabolic and functional phenotype of SM. Whereas such negative effects on SM are worsened with ageing, they are relatively improved by exercise. Importantly, our data suggest that the exercise-induced changes in the SM phenotype, in terms of increased performance (metabolic, strength and development), including lactate-induced changes, are SPARC-dependent.

Circulating levels of Irisin in obese individuals at genetic risk for Alzheimer's disease: Correlations with amyloid-β, metabolic, and neurocognitive indices

Irisin is involved in various metabolic pathways and is suggested to be a potential agent capable of preventing onset of Alzheimer's disease (AD) and ameliorating AD neuropathology and cognitive deficits. In the present study, the serum levels of Irisin and Amyloid-β (Aβ) peptides and the neurocognitive performance among obese individuals at genetic risk for AD were investigated. The correlations between Irisin and AD-related neuropathological and neurocognitive indices were also explored. Thirty-two individuals with a family history of AD (ADFH) and obesity (ADFH-obesity group) and 32 controls (ADFH-non-obesity group) were recruited. Circulating levels of Irisin, Aβ peptides, and metabolic biomarkers, as well as neurocognitive performance [e.g., behavior and brain even-related potentials (ERP)] were measured during a visuospatial working memory task. Although the ADFH-obesity group exhibited comparable reaction times, ERP N2 latency and amplitudes, and P3 latency as compared to the ADFH-non-obesity group when performing the cognitive task, they exhibited significantly lower rates of accuracy and smaller P3 amplitudes in the higher memory-load condition, even when controlling for the blood pressure and cardiorespiratory fitness co-variables. The serum levels of leptin, insulin, and glucose, and HOMA-IR were significantly higher in the ADFH-obesity group relative to the ADFH-non-obesity group, but this was not the case for the levels of Aβ1-40 and Aβ1-42. The Irisin levels approached between-group significance. Partial correlations adjusting for cardiorespiratory fitness and blood pressure showed that Irisin levels were positively associated with neurophysiological (i.e., P3 amplitude) performance in the ADFH-obesity group. The Irisin levels were not significantly correlated with the levels of Aβ1-40 and Aβ1-42. The present findings suggest that ADFH individuals with obesity exhibited neurocognitive deficits when performing the visuospatial working memory task, and serum Irisin levels could be one of the influencing factors. However, the relationship between the circulating levels of Irisin and Aβ peptides needs more evidence to support this assumption.

Possible Neuroprotective Mechanisms of Physical Exercise in Neurodegeneration

Physical exercise (PE) improves physical performance, mental status, general health, and well-being. It does so by affecting many mechanisms at the cellular and molecular level. PE is beneficial for people suffering from neuro-degenerative diseases because it improves the production of neurotrophic factors, neurotransmitters, and hormones. PE promotes neuronal survival and neuroplasticity and also optimizes neuroendocrine and physiological responses to psychosocial and physical stress. PE sensitizes the parasympathetic nervous system (PNS), Autonomic Nervous System (ANS) and central nervous system (CNS) by promoting many processes such as synaptic plasticity, neurogenesis, angiogenesis, and autophagy. Overall, it carries out many protective and preventive activities such as improvements in memory, cognition, sleep and mood; growth of new blood vessels in nervous system; and the reduction of stress, anxiety, neuro-inflammation, and insulin resistance. In the present work, the protective effects of PE were overviewed. Suitable examples from the current research work in this context are also given in the article.

Neuroprotection: Targeting Multiple Pathways by Naturally Occurring Phytochemicals

With the increase in the expectancy of the life span of humans, neurodegenerative diseases (NDs) have imposed a considerable burden on the family, society, and nation. In defiance of the breakthroughs in the knowledge of the pathogenesis and underlying mechanisms of various NDs, very little success has been achieved in developing effective therapies. This review draws a bead on the availability of the nutraceuticals to date for various NDs (Alzheimer's disease, Parkinson's disease, Amyotrophic lateral sclerosis, Huntington's disease, vascular cognitive impairment, Prion disease, Spinocerebellar ataxia, Spinal muscular atrophy, Frontotemporal dementia, and Pick's disease) focusing on their various mechanisms of action in various in vivo and in vitro models of NDs. This review is distinctive in its compilation to critically review preclinical and clinical studies of the maximum phytochemicals in amelioration and prevention of almost all kinds of neurodegenerative diseases and address their possible mechanism of action. PubMed, Embase, and Cochrane Library searches were used for preclinical studies, while ClinicalTrials.gov and PubMed were searched for clinical updates. The results from preclinical studies demonstrate the efficacious effects of the phytochemicals in various NDs while clinical reports showing mixed results with promise for phytochemical use as an adjunct to the conventional treatment in various NDs. These studies together suggest that phytochemicals can significantly act upon different mechanisms of disease such as oxidative stress, inflammation, apoptotic pathways, and gene regulation. However, further clinical studies are needed that should include the appropriate biomarkers of NDs and the effect of phytochemicals on them as well as targeting the appropriate population.

The continuum between neurodegeneration, brain plasticity, and movement: a critical appraisal

While the “physiological” aging process is associated with declines in motor and cognitive features, these changes do not significantly impair functions and activities of daily living. Differently, motor and cognitive impairment constitute the most common phenotypic expressions of neurodegeneration. Both manifestations frequently coexist in the same disease, thus making difficult to detect “pure” motor or cognitive conditions. Movement disorders are often characterized by cognitive disturbances, and neurodegenerative dementias often exhibit the occurrence of movement disorders. Such a phenotypic overlap suggests approaching these conditions by highlighting the commonalities of entities traditionally considered distinct. In the present review, we critically reappraised the common clinical and pathophysiological aspects of neurodegeneration in both animal models and patients, looking at motricity as a trait d’union over the spectrum of neurodegeneration and focusing on synaptopathy and oscillopathy as the common pathogenic background. Finally, we discussed the possible role of movement as neuroprotective intervention in neurodegenerative conditions, regardless of the etiology. The identification of commonalities is critical to drive future research and develop novel possible disease-modifying interventions.

The Effect of Short-Term Physical Activity on the Oxidative Stress in Rats with Different Stress Resistance Profiles in Cerebral Hypoperfusion

Oxidative stress associated with chronic cerebral hypoperfusion is one of the fundamental factors leading to neurodegenerative diseases. To prevent oxidative stress, physical activity is effective. Physical exercise enables development of rehabilitation techniques that can progressively increase patients' stress resistance. We determined the oxidative stress dynamics in experimental hypoperfusion and modeled rehabilitation measures, comparing sex and stress resistance levels. The experiment was performed on 240 Wistar rats of both sexes over a period of 90 days. Based on behavioral test results obtained using the open field test, the rats were divided into active animals with predicted higher stress resistance (HSR) and passive animals with predicted lower stress resistance (LSR). TBA (thiobarbituric acid) plasma concentration of the active products (malondialdehyde-MDA), blood plasma (NO-X) concentration, and L-citrulline (LC) concentration were determined spectrophotometrically at the corresponding wave length (nm). The intensity of oxidative stress was evaluated using the chemoluminscent method to determine the blood plasma antioxidant activity on the BCL-07 biochemoluminometer. This study revealed two stages of oxidative stress: a less pronounced phase covering the first days after surgery and a main one, which starts from the month after the operation to 3 months. Female sex and a high initial level of stress resistance reduced the severity of oxidative stress. Physical activity commencing a week after the surgery resulted in "reloading" the adaptive mechanisms and slowed the onset of the main stage, leading to a decrease in the free-radical process in all studied subgroups and the greater blood plasma (NO)-X decrease in the male animals. Future neuropharmacological intervention most likely will be able to determine the pathophysiology mechanism of chronic brain hypoperfusion and potentially extending adaptive responses.

Klotho Pathways, Myelination Disorders, Neurodegenerative Diseases, and Epigenetic Drugs

In this review we outline a rationale for identifying neuroprotectants aimed at inducing endogenous Klotho activity and expression, which is epigenetic action, by definition. Such an approach should promote remyelination and/or stimulate myelin repair by acting on mitochondrial function, thereby heralding a life-saving path forward for patients suffering from neuroinflammatory diseases. Disorders of myelin in the nervous system damage the transmission of signals, resulting in loss of vision, motion, sensation, and other functions depending on the affected nerves, currently with no effective treatment. Klotho genes and their single-pass transmembrane Klotho proteins are powerful governors of the threads of life and death, true to the origin of their name, Fates, in Greek mythology. Among its many important functions, Klotho is an obligatory co-receptor that binds, activates, and/or potentiates critical fibroblast growth factor activity. Since the discovery of Klotho a little over two decades ago, it has become ever more apparent that when Klotho pathways go awry, oxidative stress and mitochondrial dysfunction take over, and age-related chronic disorders are likely to follow. The physiological consequences can be wide ranging, potentially wreaking havoc on the brain, eye, kidney, muscle, and more. Central nervous system disorders, neurodegenerative in nature, and especially those affecting the myelin sheath, represent worthy targets for advancing therapies that act upon Klotho pathways. Current drugs for these diseases, even therapeutics that are disease modifying rather than treating only the symptoms, leave much room for improvement. It is thus no wonder that this topic has caught the attention of biomedical researchers around the world.

Could Heat Therapy Be an Effective Treatment for Alzheimer's and Parkinson's Diseases? A Narrative Review

Neurodegenerative diseases involve the progressive deterioration of structures within the central nervous system responsible for motor control, cognition, and autonomic function. Alzheimer's disease and Parkinson's disease are among the most common neurodegenerative disease and have an increasing prevalence over the age of 50. Central in the pathophysiology of these neurodegenerative diseases is the loss of protein homeostasis, resulting in misfolding and aggregation of damaged proteins. An element of the protein homeostasis network that prevents the dysregulation associated with neurodegeneration is the role of molecular chaperones. Heat shock proteins (HSPs) are chaperones that regulate the aggregation and disaggregation of proteins in intracellular and extracellular spaces, and evidence supports their protective effect against protein aggregation common to neurodegenerative diseases. Consequently, upregulation of HSPs, such as HSP70, may be a target for therapeutic intervention for protection against neurodegeneration. A novel therapeutic intervention to increase the expression of HSP may be found in heat therapy and/or heat acclimation. In healthy populations, these interventions have been shown to increase HSP expression. Elevated HSP may have central therapeutic effects, preventing or reducing the toxicity of protein aggregation, and/or peripherally by enhancing neuromuscular function. Broader physiological responses to heat therapy have also been identified and include improvements in muscle function, cerebral blood flow, and markers of metabolic health. These outcomes may also have a significant benefit for people with neurodegenerative disease. While there is limited research into body warming in patient populations, regular passive heating (sauna bathing) has been associated with a reduced risk of developing neurodegenerative disease. Therefore, the emerging evidence is compelling and warrants further investigation of the potential benefits of heat acclimation and passive heat therapy for sufferers of neurodegenerative diseases.

Short-term resistance exercise inhibits neuroinflammation and attenuates neuropathological changes in 3xTg Alzheimer's disease mice

BACKGROUND

Both human and animal studies have shown beneficial effects of physical exercise on brain health but most tend to be based on aerobic rather than resistance type regimes. Resistance exercise has the advantage of improving both muscular and cardiovascular function, both of which can benefit the frail and the elderly. However, the neuroprotective effects of resistance training in cognitive impairment are not well characterized.

METHODS

We evaluated whether short-term resistant training could improve cognitive function and pathological changes in mice with pre-existing cognitive impairment. Nine-month-old 3xTg mouse underwent a resistance training protocol of climbing up a 1-m ladder with a progressively heavier weight loading.

RESULTS

Compared with sedentary counterparts, resistance training improved cognitive performance and reduced neuropathological and neuroinflammatory changes in the frontal cortex and hippocampus of mice. In line with these results, inhibition of pro-inflammatory intracellular pathways was also demonstrated.

CONCLUSIONS

Short-term resistance training improved cognitive function in 3xTg mice, and conferred beneficial effects on neuroinflammation, amyloid and tau pathology, as well as synaptic plasticity. Resistance training may represent an alternative exercise strategy for delaying disease progression in Alzheimer's disease.

Exercise enhances the effectiveness of vitamin D therapy in rats with Alzheimer's disease: emphasis on oxidative stress and inflammation

Alzheimer's disease (AD) is characterized by gradual loss of memory and cognitive functions which can affect anyone. Authors declared that there is a link between vitamin D and brain function. It has been proven that vitamin D plays an important role in improving AD cognitive functions. Researchers have found that exercise has many beneficial effects on humans. In addition to cardioprotection, it has been demonstrated that exercise provides an effective improvement in different brain functions. So in our study, we aimed to evaluate the effect of each of vitamin D and/ or exercise on AD and if they could be used as a potential line for treating AD. This study was conducted on fifty female white albino rats divided equally into 5 groups: control group, Alzheimer group induced by Lipopolysaccharide, Alzheimer group treated with vitamin D, Alzheimer group treated with exercise and Alzheimer group treated with both vitamin D and exercise. The following parameters were assessed in rat brain tissues: acetylcholine esterase (AChE) activity, levels of amyloid β 42 and tau proteins, dopamine brain neurotransmitter, BDNF and NGF by ELISA. Serum levels of IL-6 and IL-10 were assessed by ELISA. MDA, GSH and vitamin D levels were also estimated in addition to cognitive function tests and histopathological examination of rat brain tissues. In Alzheimer group, there was a significant increase in the proinflammatory cytokine IL-6, the lipid peroxidation marker MDA, amyloid β and tau proteins^, levels. In addition to a significant increase in time consumed in T-maze test. Alzheimer group also showed a significant decrease in the anti-inflammatory cytokine IL-10, the anti-oxidative stress biomarker GSH, the neurotransmitters AChE and dopamine, and the growth factors BDNF and NGF as well as serum vitamin D levels. Treatment with either vitamin D or exercise significantly improved cognitive dysfunction and the histopathological picture of the brains of Alzheimer's rats with the best results in combined vitamin D and exercise treated group. The treated groups, especially combined vitamin D and exercise group, showed a significant decrease in IL-6, MDA, amyloid β and tau proteins levels, but on the other hand they showed a significant increase in IL-10, GSH, AChE, dopamine, BDNF and NGF. These data suggest that combined vitamin D and exercise could be considered as a potential and effective line for treating AD.

Swim exercise in Caenorhabditis elegans extends neuromuscular and gut healthspan, enhances learning ability, and protects against neurodegeneration

Exercise is a powerful antiaging intervention that protects against cardiovascular disease, dementia, diabetes, sarcopenia, and cancer. How exercise promotes health benefits to multiple tissues in the body, however, remains poorly understood. We establish a young adult swim exercise regimen for the short-lived nematode Caenorhabditis elegans that induces health benefits at the neuromuscular, intestinal, and cognitive levels and protects against neurodegeneration in models of tauopathy, Alzheimer’s disease, and Huntington’s disease. Importantly, we found that swim exercise performed exclusively in early adulthood promotes long-lasting systemic benefits that are still detectable in midlife. The advantages of C. elegans as a short-lived genetic model will allow for dissection of the molecular circuitry involved in system-wide exercise benefits.

Regular physical exercise is the most efficient and accessible intervention known to promote healthy aging in humans. The molecular and cellular mechanisms that mediate system-wide exercise benefits, however, remain poorly understood, especially as applies to tissues that do not participate directly in training activity. The establishment of exercise protocols for short-lived genetic models will be critical for deciphering fundamental mechanisms of transtissue exercise benefits to healthy aging. Here we document optimization of a long-term swim exercise protocol for Caenorhabditis elegans and we demonstrate its benefits to diverse aging tissues, even if exercise occurs only during a restricted phase of adulthood. We found that multiple daily swim sessions are essential for exercise adaptation, leading to body wall muscle improvements in structural gene expression, locomotory performance, and mitochondrial morphology. Swim exercise training enhances whole-animal health parameters, such as mitochondrial respiration and midlife survival, increases functional healthspan of the pharynx and intestine, and enhances nervous system health by increasing learning ability and protecting against neurodegeneration in models of tauopathy, Alzheimer’s disease, and Huntington’s disease. Remarkably, swim training only during early adulthood induces long-lasting systemic benefits that in several cases are still detectable well into midlife. Our data reveal the broad impact of swim exercise in promoting extended healthspan of multiple C. elegans tissues, underscore the potency of early exercise experience to influence long-term health, and establish the foundation for exploiting the powerful advantages of this genetic model for the dissection of the exercise-dependent molecular circuitry that confers system-wide health benefits to aging adults.