Exercise induces behavioral recovery and attenuates neurochemical deficits in rodent models of Parkinson's disease

Moderate intensity aerobic exercise alleviates motor deficits in 6-OHDA lesioned rats and reduces serum levels of biomarkers of Parkinson's disease severity without recovery of striatal dopamine or tyrosine hydroxylase

Alleviation of motor impairment by aerobic exercise (AE) in Parkinson's disease (PD) patients points to activation of neurobiological mechanisms that may be targetable by therapeutic approaches. However, evidence for AE-related recovery of striatal dopamine (DA) signaling or tyrosine hydroxylase (TH) loss has been inconsistent in rodent studies. This ambiguity may be related to the timing of AE intervention in relation to the status of nigrostriatal neuron loss. Here, we replicated human PD at diagnosis by establishing motor impairment with >80% striatal DA and TH loss prior to initiating AE, and assessed its potential to alleviate motor decline and restore DA and TH loss. We also evaluated if serum levels of neurofilament light (NfL) and glial fibrillary acidic protein (GFAP), biomarkers of human PD severity, changed in response to AE. 6-hydroxydopamine (6-OHDA) was infused unilaterally into rat medial forebrain bundle to induce progressive nigrostriatal neuron loss over 28 days. Moderate intensity AE (3× per week, 40 min/session), began 8-10 days post-lesion following establishment of impaired forelimb use. Striatal tissue DA, TH protein and mRNA, and serum levels of NfL/GFAP were determined 3-wks after AE began. Despite severe striatal DA depletion at AE initiation, forelimb use deficits and hypokinesia onset were alleviated by AE, without recovery of striatal DA or TH protein loss, but reduced NfL and GFAP serum levels. This proof-of-concept study shows AE alleviates motor impairment when initiated with >80% striatal DA loss without obligate recovery of striatal DA or TH protein. Moreover, the AE-related reduction of NfL and GFAP serum levels may serve as objective blood-based biomarkers of AE efficacy.

10 weeks low intensity treadmill exercise intervention ameliorates motor deficits and sustains muscle mass via decreasing oxidative damage and increasing mitochondria function in a rat model of Parkinson's disease

AIMS

Parkinson's disease (PD) is characterized by loss of dopamine neurons in the brain, which leads to motor dysfunction; excessive inflammation induces neuronal death. This study aimed to determine the most effective exercise modality to improve motor dysfunction in PD by comparing three different exercise regimens (low-intensity treadmill, high-intensity treadmill, and swimming).

MATERIALS AND METHODS

The rat model for PD was established through stereotaxic surgery, inducing unilateral 6-OHDA (6-hydroxydopamine) lesions. The low-intensity treadmill regimen exerted better protective effects on neurological and motor functions in a rat model of unilateral 6-OHDA-induced PD compared to high-intensity treadmill and swimming. The most suitable exercise regimen and the optimal duration of daily exercise (15 or 30 min) on motor activity and oxidative stress parameters were evaluated.

KEY FINDINGS

Comparison of 15 and 30 min low-intensity treadmill regimens (10 m/min) revealed 30 min daily exercise was the optimal duration and had more favorable impacts on neurological and motor function. Furthermore, we assessed the neuroprotective effects of exercising for 15 and 30 min per day for either four or ten weeks; 30 min of daily exercise for ten weeks improved mitochondrial function, the antioxidant defense system, neurotrophic factors, and muscle mass, and thereby provided protection against dopaminergic neuron loss, and motor dysfunction in rats with 6-OHDA-induced PD.

SIGNIFICANCE

30 min of daily low-intensity treadmill exercise over 10 weeks resulted in heightened mitochondrial function in both muscle and brain tissues, therefore, yielded a neuroprotective effect against the loss of dopaminergic neurons and motor dysfunction in PD rats.

Dose-response effects of physical exercise standardized volume on peripheral biomarkers, clinical response, and brain connectivity in Parkinson's disease: a prospective, observational, cohort study

Background

Exercise has been proposed as the "Universal Prescription for Parkinson's Disease"; however, the specificity of exercise dose in terms of frequency, intensity, duration, and type to be prescribed remains to be elucidated. The 2018 US updated guidelines and WHO Guidelines on Physical Activity and Sedentary Behavior recommend older adults (> 65+ years) to achieve weekly minimal activity levels, indicating the intensity of aerobic exercise as the metabolic equivalent of task and duration as minutes/week (150-300 min/week at a moderate intensity of 3-5.9 MET- or 75-150 min/week of a vigorous intensity of ≥6 MET). Translating these recommendations to PD patients, the study aimed to assess the dose-response effects of standardized volume of structured exercise, measured as METs-minutes/week (weekly energy expenditure) of two different rehabilitation settings to quantify the change in neurotrophic factors. The exercise-induced benefits between the two rehabilitation settings will be evaluated based on motor and non-motor symptoms, kinematic parameters of gait, cognitive function, quality of life, and cortical activity and brain connectivity.

Methods

METEX-PD is a pilot, prospective, observational, cohort study. The study will enroll consecutively thirty (N = 30) participants with mild-to-moderate Parkinson's disease diagnosis to be assigned to a non-intensive or intensive rehabilitation group. The non-intensive rehabilitation group will achieve a range of 180-270 METs-min/week (90 min/week of low-intensity aerobic exercise, 2-3 METs), while the intensive rehabilitation group will exercise at 1350-1980 METs-min/week (225 min/week of high-intensity aerobic exercise, 6-8.8 METs). The METEX-PD trial will last 12 weeks, including 4 weeks of aerobic training program and two follow-ups. Assessments will be performed at baseline (T0), at the end of the exercise program (T1-end of the program), and 4- and 8 weeks after the end of the training program (FU-1 and FU-2). The primary outcome is the change from baseline in peripheral blood BDNF levels. Secondary outcomes are differences in peripheral biomarkers, functional-motor assessments, clinical-functional evaluations, and brain imaging.

Conclusion

METEX-PD trial will enable us to estimate the change in BDNF levels and other peripheral biomarkers under precise exercise-induced energy expenditure. The primary results of the METEX-PD study will allow the development of a larger multicenter randomized controlled trial to investigate the molecular pathways inducing the change in selected neurotrophic factors, such as BDNF, IGF-1, or irisin, and the downstream mechanisms of neuroplasticity in PD patients.

Pharmacological Assessment of Aqueous Ethanolic Extract of Thalictrum Foetidum Against Haloperidol-Induced Parkinson's Like Symptoms in Animal Model: A Dose-Dependent Study With Mechanistic Approach

Introduction: Parkinson's disease (PD) is characterized by dopamine deficiency in the corpus striatum due to the degeneration of dopaminergic neurons in the substantia nigra. Symptoms include bradykinesia, resting tremors, unstable posture, muscular rigidity, and a shuffled gait. Thalictrum foetidum is traditionally used for neurodegenerative disorders. Objectives: This study aimed to explore the therapeutic potential of aqueous ethanolic extract of Thalictrum foetidum (AETF) against Parkinson-like symptoms and to investigate its underlying mechanism. Methodology: Thirty-six albino mice were randomly divided into 6 groups (n = 6): normal control, disease control, standard treatment (levodopa/carbidopa, 100/25 mg/kg), and 3 treatment groups (AETF at 200, 400, and 600 mg/kg). One hour before treatment, haloperidol (1 mg/kg, i. p.) was administered to induce Parkinson's disease in all groups except the normal control group. Results: Behavioral analysis showed significant improvement (P < .001) in motor function, muscular coordination, and reduced muscular rigidity and tremors. AETF also reduced oxidative stress. Histological examination of the brain showed reduced Lewy bodies, neurofibrillary tangles, and plaque formation. Conclusion: AETF alleviated PD symptoms by reducing neurodegeneration, modulating oxidative stress, and inhibiting the expression of nuclear factor-κB (NF-κB) and associated inflammatory cytokines, such as tumor necrosis factor-alpha (TNF-α) and interleukin-6 (IL-6).

Automatic speaking valve in tracheo-esophageal speech: treatment proposal for a widespread usage

PURPOSE

Aim of this study was to calculate the percentage of the Automatic Speaking Valve (ASV) use in a large cohort of laryngectomized patients with voice prosthesis (VP) and to analyze the main reasons for non-use. Subsequently, a specific rehabilitation training was proposed.

METHODS

One hundred-ten laryngectomized patients with VP were enrolled in the first phase of the study (census). Among them, 57 patients were included in the second phase (intervention), in which a training based on moving phonatory exercises was proposed. Structured questionnaires were used before and after training in order to investigate ASV use rate (days/week and hours/day; reasons for impeding the ASV use), average adhesive life-time during ASV use; hands-free speech duration; skin irritation. Patients also expressed their degree of on a VAS scale from 0 to 100.

RESULTS

In the census phase the percentage of use of ASV (everyday, without problems) was equal to 17.27% (19/110 patients). The main causes of disuse concerned excessive fatigue and poor durability of the adhesives. The analysis of the results pre vs. post-training showed a statistically significant increase (p < 0.05) in all the investigated parameters. Patients reported a good level of treatment compliance (average frequency of performing exercises equal to 4.2 ± 2.5 days/week for 1.4 ± 1.01 h/day) and high degrees of satisfaction. After treatment, the percentage of use of AVS increased by 43% reaching a rate of 60% (66/110 patients).

CONCLUSION

A specific and targeted approach that simulate the phonatory and breathing difficulties of everyday life can increase the ASV usage rate.

Aerobic exercise improves depressive symptoms in the unilateral 6-OHDA-lesioned rat model of Parkinson's disease

Aerobic exercise has been shown to have established benefits on motor function in Parkinson's disease (PD). However, the impact of exercise on depressive symptoms in PD remains unclear. This study aimed to investigate the effects of regular exercise, specifically using a forced running wheel, on both motor performance and the prevalence of depression in a unilateral 6-OHDA-lesioned rat model of PD. The behavioral outcomes of exercise were assessed through the rotarod test (RT), forelimb adjusting step test (FAST), sucrose consumption test (SCT), and novelty sucrose splash test (NSST). Our data revealed evident depressive symptoms in the PD animals, characterized by reduced sucrose consumption in the SCT and diminished exploratory activity in the NSST compared to the naïve control group. Specifically, after 11 weeks of exercise, the PD exercise group demonstrated the most significant improvements in sucrose consumption in the SCT. Additionally, this group exhibited reduced immobility and increased exploratory behavior compared to the PD control group in the NSST. Furthermore, the PD exercise group displayed the greatest improvement in correcting forelimb stepping bias. Our results suggested that a regimen of running wheel exercise enhances motor abilities and mitigates the occurrence of depressive behaviors caused by 6-OHDA dopamine depletion in the PD rat model.

Combining physical & cognitive training with iPSC-derived dopaminergic neuron transplantation promotes graft integration & better functional outcome in parkinsonian marmosets

Parkinson's disease (PD) is a relentlessly progressive and currently incurable neurodegenerative disease with significant unmet medical needs. Since PD stems from the degeneration of midbrain dopaminergic (DA) neurons in a defined brain location, PD patients are considered optimal candidates for cell replacement therapy. Clinical trials for cell transplantation in PD are beginning to re-emerge worldwide with a new focus on induced pluripotent stem cells (iPSCs) as a source of DA neurons since they can be derived from adult somatic cells and produced in large quantities under current good manufacturing practices. However, for this therapeutic strategy to be realized as a viable clinical option, fundamental translational challenges need to be addressed including the manufacturing process, purity and efficacy of the cells, the method of delivery, the extent of host reinnervation and the impact of patient-centered adjunctive interventions. In this study we report on the impact of physical and cognitive training (PCT) on functional recovery in the nonhuman primate (NHP) model of PD after cell transplantation. We observed that at 6 months post-transplant, the PCT group returned to normal baseline in their daily activity measured by actigraphy, significantly improved in their sensorimotor and cognitive tasks, and showed enhanced synapse formation between grafted cells and host cells. We also describe a robust, simple, efficient, scalable, and cost-effective manufacturing process of engraftable DA neurons derived from iPSCs. This study suggests that integrating PCT with cell transplantation therapy could promote optimal graft functional integration and better outcome for patients with PD.

Intense exercise increases dopamine transporter and neuromelanin concentrations in the substantia nigra in Parkinson's disease

Parkinson's disease (PD) is characterized by a progressive loss of dopaminergic neurons. Exercise has been reported to slow the clinical progression of PD. We evaluated the dopaminergic system of patients with mild and early PD before and after a six-month program of intense exercise. Using 18F-FE-PE2I PET imaging, we measured dopamine transporter (DAT) availability in the striatum and substantia nigra. Using NM-MRI, we evaluated the neuromelanin content in the substantia nigra. Exercise reversed the expected decrease in DAT availability into a significant increase in both the substantia nigra and putamen. Exercise also reversed the expected decrease in neuromelanin concentration in the substantia nigra into a significant increase. These findings suggest improved functionality in the remaining dopaminergic neurons after exercise. Further research is needed to validate our findings and to pinpoint the source of any true neuromodulatory and neuroprotective effects of exercise in PD in large clinical trials.

Risk factors associated with age at onset of Parkinson's disease in the UK Biobank

Substantial evidence shown that the age at onset (AAO) of Parkinson's disease (PD) is a major determinant of clinical heterogeneity. However, the mechanisms underlying heterogeneity in the AAO remain unclear. To investigate the risk factors with the AAO of PD, a total of 3156 patients with PD from the UK Biobank were included in this study. We evaluated the effects of polygenic risk scores (PRS), nongenetic risk factors, and their interaction on the AAO using Mann-Whitney U tests and regression analyses. We further identified the genes interacting with nongenetic risk factors for the AAO using genome-wide environment interaction studies. We newly found physical activity (P < 0.0001) was positively associated with AAO and excessive daytime sleepiness (P < 0.0001) was negatively associated with AAO, and reproduced the positive associations of smoking and non-steroidal anti-inflammatory drug intake and the negative association of family history with AAO. In the dose-dependent analyses, smoking duration (P = 1.95 × 10-6), coffee consumption (P = 0.0150), and tea consumption (P = 0.0008) were positively associated with AAO. Individuals with higher PRS had younger AAO (P = 3.91 × 10-5). In addition, we observed a significant interaction between the PRS and smoking for AAO (P = 0.0316). Specifically, several genes, including ANGPT1 (P = 7.17 × 10-7) and PLEKHA6 (P = 4.87 × 10-6), may influence the positive relationship between smoking and AAO. Our data suggests that genetic and nongenetic risk factors are associated with the AAO of PD and that there is an interaction between the two.

Recent Advancements in Extraction Techniques of Ashwagandha (Withania somnifera) with Insights on Phytochemicals, Structural Significance, Pharmacology, and Current Trends in Food Applications

Ashwagandha, also known as Withania somnifera (WS), is an ayurvedic botanical plant with numerous applications in dietary supplements and traditional medicines worldwide. Due to the restorative qualities of its roots, WS has potent therapeutic value in traditional Indian (Ayurvedic, Unani, Siddha) and modern medicine recognized as the "Indian ginseng". The presence of phytochemical bioactive compounds such as withanolides, withanosides, alkaloids, flavonoids, and phenolic compounds has an important role in the therapeutic and nutritional properties of WS. Thus, the choice of WS plant part and extraction solvents, with conventional and modern techniques, plays a role in establishing WS as a potential nutraceutical product. WS has recently made its way into food supplements and products, such as baked goods, juices, beverages, sweets, and dairy items. The review aims to cover the key perspectives about WS in terms of plant description, phytochemistry, structural significance, and earlier reported extraction methodologies along with the analytical and pharmacological landscape in the area. It also attempts to iterate the key limitations and further insights into extraction techniques and bioactive standardization with the regulatory framework. It presents a key to the future development of prospective applications in foods such as food supplements or functional foods.

A Pilot Study of the Effect of a Non-Contact Boxing Exercise Intervention on Respiratory Pressure and Phonation Aerodynamics in People with Parkinson's Disease

This study investigated the effects of a non-contact boxing exercise program on maximum expiratory pressure and aerodynamic voice measurements.

METHODS

Eight adult males diagnosed with Parkinson's disease participated in the study. Individuals participated in twice-weekly exercise classes lasting one hour across 12-months. Dependent variables were measured on three baseline days and then at six additional time points. A pressure meter acquired maximum expiratory pressure, and a pneumotachograph system acquired transglottal airflow and subglottal air pressure.

RESULTS

Measures of average maximum expiratory pressure significantly increased after 9- and 12- months of exercise when compared to baseline. There was an increasing trend for these measures in all participants, with a corresponding large effect size. Measures of transglottal airflow and subglottal pressure did not change over the course of 9- or 12-months, although their stability may indicate that the exercise program influenced maintenance of respiratory-phonatory coordination during voicing.

CONCLUSIONS

A non-contact boxing exercise program had a significant effect on maximum expiratory pressure in people with Parkinson's disease. The aerobic nature of the program and challenges to the respiratory muscles potentially explain the "ingredient" causing this effect. The small sample size of this pilot study necessitates future research incorporating larger and more diverse participants.

Moderate intensity aerobic exercise in 6-OHDA-lesioned rats alleviates established motor deficits and reduces neurofilament light and glial fibrillary acidic protein serum levels without increased striatal dopamine or tyrosine hydroxylase protein

Background

Alleviation of motor impairment by aerobic exercise (AE) in Parkinson's disease (PD) points to a CNS response that could be targeted by therapeutic approaches, but recovery of striatal dopamine (DA) or tyrosine hydroxylase (TH) has been inconsistent in rodent studies.

Objective

To increase translation of AE, 3 components were implemented into AE design to determine if recovery of established motor impairment, concomitant with >80% striatal DA and TH loss, was possible. We also evaluated if serum levels of neurofilament light (NfL) and glial fibrillary acidic protein (GFAP), blood-based biomarkers of disease severity in human PD, were affected.

Methods

We used a 6-OHDA hemiparkinson rat model featuring progressive nigrostriatal neuron loss over 28 days, with impaired forelimb use 7 days post-lesion, and hypokinesia onset 21 days post-lesion. After establishing forelimb use deficits, moderate intensity AE began 1-3 days later, 3x per week, for 40 min/session. Motor assessments were conducted weekly for 3 wks, followed by determination of striatal DA, TH protein and mRNA, and NfL and GFAP serum levels.

Results

Seven days after 6-OHDA lesion, recovery of depolarization-stimulated extracellular DA and DA tissue content was <10%, representing severity of DA loss in human PD, concomitant with 50% reduction in forelimb use. Despite severe DA loss, recovery of forelimb use deficits and alleviation of hypokinesia progression began after 2 weeks of AE and was maintained. Increased NfLand GFAP levels from lesion were reduced by AE. Despite these AE-driven changes, striatal DA tissue and TH protein levels were unaffected.

Conclusions

This proof-of-concept study shows AE, using exercise parameters within the capabilities most PD patients, promotes recovery of established motor deficits in a rodent PD model, concomitant with reduced levels of blood-based biomarkers associated with PD severity, without commensurate increase in striatal DA or TH protein.

Dysphagia in Parkinson Disease: Part II-Current Treatment Options and Insights from Animal Research

Purpose of Review

Dysphagia is highly prevalent in Parkinson disease (PD) but is not typically identified nor treated until later in the disease process. This review summarizes current pharmacological, surgical, and behavioral treatments for PD-associated dysphagia and contributions from translational animal research.

Recent Findings

Swallowing is a complex physiologic process controlled by multiple brain regions and neurotransmitter systems. As such, interventions that target nigrostriatal dopamine dysfunction have limited or detrimental effects on swallowing outcomes. Behavioral interventions can help target PD-associated dysphagia in mid-to-late stages. Animal research is necessary to refine treatments and useful in studying prodromal dysphagia.

Summary

Dysphagia is an early, common, and debilitating sign of PD. Current pharmacological and surgical interventions are not effective in ameliorating swallowing dysfunction; behavioral intervention remains the most effective approach for dysphagia treatment. Animal research has advanced our understanding of mechanisms underlying PD and PD-associated dysphagia, and continues to show translational promise for the study of dysphagia treatment options.

Exercise Promotes Tissue Regeneration: Mechanisms Involved and Therapeutic Scope

Exercise has well-recognized beneficial effects on the whole body. Previous studies suggest that exercise could promote tissue regeneration and repair in various organs. In this review, we have summarized the major effects of exercise on tissue regeneration primarily mediated by stem cells and progenitor cells in skeletal muscle, nervous system, and vascular system. The protective function of exercise-induced stem cell activation under pathological conditions and aging in different organs have also been discussed in detail. Moreover, we have described the primary molecular mechanisms involved in exercise-induced tissue regeneration, including the roles of growth factors, signaling pathways, oxidative stress, metabolic factors, and non-coding RNAs. We have also summarized therapeutic approaches that target crucial signaling pathways and molecules responsible for exercise-induced tissue regeneration, such as IGF1, PI3K, and microRNAs. Collectively, the comprehensive understanding of exercise-induced tissue regeneration will facilitate the discovery of novel drug targets and therapeutic strategies.

Behavioral context improves optogenetic stimulation of transplanted dopaminergic cells in unilateral 6-OHDA rats

Stem cell therapy has long been a popular method of treatment for Parkinson's disease currently being researched in both preclinical and clinical settings. While early clinical results are based upon fetal tissue transplants rather than stem cell transplants, the lack of successful integration in some patients and gradual loss of effect in others suggests a more robust protocol is needed. We propose a two-front approach, one where transplants are directly stimulated in coordination with host activity elicited by behavioral tasks, which we refer to as behavioral context. After a pilot with unilateral 6-OHDA rats transplanted with dopaminergic cells differentiated from mesenchymal stem cells that were optogenetically stimulated during a swim task, we discovered that early stimulation predicted lasting reduction of motor deficits, even in the absence of later stimulation. This led to a follow-up with n = 21 rats split into three groups: one stimulated while performing a swim task (Stim-Swim; St-Sw), one not stimulated while swimming (NoStim-Swim; NSt-Sw), and one stimulated while stationary in a bowl (Stim-NoSwim; St-NSw). After initial stimulation (or lack thereof), all rats were retested two and seven days later with the swim task in the absence of stimulation. The St-Sw group gradually achieved and maintained symmetrical limb use, whereas the NSt-Sw group showed persistent asymmetry and the St-NSw group showed mixed results. This supports the notion that stem cell therapy should integrate targeted stimulation of the transplant with behavioral stimulation of the host tissue to encourage proper functional integration of the graft.

Vitamin D (VD3) Intensifies the Effects of Exercise and Prevents Alterations of Behavior, Brain Oxidative Stress, and Neuroinflammation, in Hemiparkinsonian Rats

In the present study, we investigated the effects of physical exercise in the presence of Vitamin D3 (VD3), on 6-hydroxydopamine (6-OHDA)-lesioned hemiparkinsonian rats. The animals were divided into sham-operated (SO), 6-OHDA-lesioned, and 6-OHDA-lesioned plus VD3 (1 µg/kg, 21 days), in the absence (no exercise, NE) and presence (with exercise, WE) of physical exercise on a treadmill (30 min, speed of 20 cm/s, once a day/21 days). This procedure started, 24 h after the stereotaxic surgery (injections of 6-OHDA into the right striatum). The animals were then subjected to behavioral (rotarod, open field, and apomorphine tests) and their brain areas were dissected for neurochemical, dopamine (DA), 3,4-dihydroxyphenylacetic acid (DOPAC) determinations, and immunohistochemical studies for tyrosine hydroxylase (TH), dopamine transporter (DAT), and vitamin D receptor (VD3R). The effects on the brain oxidative stress: nitrite/nitrate, glutathione (GSH), and malondialdehyde (MDA) measurements were also evaluated. Behavioral changes of the 6-OHDA lesioned group were improved by exercise plus VD3. Similar results were observed in dopamine (DA) and 3,4-dihydroxyphenylacetic acid (DOPAC) concentrations increased by exercise and VD3, compared with SO groups. Additionally, tyrosine hydroxylase (TH) and dopamine transporter (DAT) immunoexpressions were decreased in the 6-OHDA-lesioned groups, with values normalized after exercise and VD3. The VD3 receptor immunoexpression decreased in the 6-OHDA (NE) group, and this was attenuated by exercise, especially after VD3. While 6-OHDA lesions increased, VD3 supplementation decreased the oxidative stress, which was intensified by exercise. VD3 showed neuroprotective properties that were intensified by physical exercise. These VD3 actions on hemiparkinsonian rats are possibly related to its antioxidant and anti-inflammatory effects.

Healthy lifestyles and wellbeing reduce neuroinflammation and prevent neurodegenerative and psychiatric disorders

Since the mid-20th century, Western societies have considered productivity and economic outcomes are more important than focusing on people's health and wellbeing. This focus has created lifestyles with high stress levels, associated with overconsumption of unhealthy foods and little exercise, which negatively affect people's lives, and subsequently lead to the development of pathologies, including neurodegenerative and psychiatric disorders. Prioritizing a healthy lifestyle to maintain wellbeing may slow the onset or reduce the severity of pathologies. It is a win-win for everyone; for societies and for individuals. A balanced lifestyle is increasingly being adopted globally, with many doctors encouraging meditation and prescribing non-pharmaceutical interventions to treat depression. In psychiatric and neurodegenerative disorders, the inflammatory response system of the brain (neuroinflammation) is activated. Many risks factors are now known to be linked to neuroinflammation such as stress, pollution, and a high saturated and trans fat diet. On the other hand, many studies have linked healthy habits and anti-inflammatory products with lower levels of neuroinflammation and a reduced risk of neurodegenerative and psychiatric disorders. Sharing risk and protective factors is critical so that individuals can make informed choices that promote positive aging throughout their lifespan. Most strategies to manage neurodegenerative diseases are palliative because neurodegeneration has been progressing silently for decades before symptoms appear. Here, we focus on preventing neurodegenerative diseases by adopting an integrated "healthy" lifestyle approach. This review summarizes the role of neuroinflammation on risk and protective factors of neurodegenerative and psychiatric disorders.

Association of Osteoarthritis With Increased Risk of Parkinson's Disease: A Population-Based, Longitudinal Follow-Up Study

OBJECTIVE

To investigate whether patients with osteoarthritis (OA) are at a higher risk of developing Parkinson's disease (PD).

METHODS

This retrospective cohort study was conducted using Taiwan's Longitudinal Health Insurance Database 2005. We enrolled 33,360 patients who were 50-64 years old and had OA in 2002-2005 to form the OA group. The comparison group consisted of 33,360 age- and sex-matched, randomly sampled subjects without OA. Then, their PD-free survival curves were generated using the Kaplan-Meier method. Multivariable Cox proportional hazards regression analysis was employed to estimate the effect of having OA on patients' subsequent risk of PD.

RESULTS

Of the 2 groups, the OA group had a significantly higher risk of developing PD (adjusted hazard ratio [HR_adj ] 1.41 [95% confidence interval (95% CI) 1.16-1.70], P = 0.0003). The PD-free survival rate of the OA group was also significantly lower than that of the comparison group (P = 0.0004). The subgroup analysis showed that patients with knee or hip OA appeared to have a higher magnitude of PD risk (HR_adj 1.55 [95% CI 1.14-2.11]) than patients with non-knee and non-hip OA (HR_adj 1.42 [95% CI 1.06-1.89]) or with uncategorized OA (HR_adj 1.32 [95% CI 1.05-1.64]).

CONCLUSION

Our findings suggest that OA is linked to an increased risk of developing PD.

Study in Parkinson's disease of exercise phase 3 (SPARX3): study protocol for a randomized controlled trial

BACKGROUND

To date, no medication has slowed the progression of Parkinson's disease (PD). Preclinical, epidemiological, and experimental data on humans all support many benefits of endurance exercise among persons with PD. The key question is whether there is a definitive additional benefit of exercising at high intensity, in terms of slowing disease progression, beyond the well-documented benefit of endurance training on a treadmill for fitness, gait, and functional mobility. This study will determine the efficacy of high-intensity endurance exercise as first-line therapy for persons diagnosed with PD within 3 years, and untreated with symptomatic therapy at baseline.

METHODS

This is a multicenter, randomized, evaluator-blinded study of endurance exercise training. The exercise intervention will be delivered by treadmill at 2 doses over 18 months: moderate intensity (4 days/week for 30 min per session at 60-65% maximum heart rate) and high intensity (4 days/week for 30 min per session at 80-85% maximum heart rate). We will randomize 370 participants and follow them at multiple time points for 24 months. The primary outcome is the Movement Disorders Society-Unified Parkinson's Disease Rating Scale (MDS-UPDRS) motor score (Part III) with the primary analysis assessing the change in MDS-UPDRS motor score (Part III) over 12 months, or until initiation of symptomatic antiparkinsonian treatment if before 12 months. Secondary outcomes are striatal dopamine transporter binding, 6-min walk distance, number of daily steps, cognitive function, physical fitness, quality of life, time to initiate dopaminergic medication, circulating levels of C-reactive protein (CRP), and brain-derived neurotrophic factor (BDNF). Tertiary outcomes are walking stride length and turning velocity.

DISCUSSION

SPARX3 is a Phase 3 clinical trial designed to determine the efficacy of high-intensity, endurance treadmill exercise to slow the progression of PD as measured by the MDS-UPDRS motor score. Establishing whether high-intensity endurance treadmill exercise can slow the progression of PD would mark a significant breakthrough in treating PD. It would have a meaningful impact on the quality of life of people with PD, their caregivers and public health.

TRIAL REGISTRATION

ClinicalTrials.gov NCT04284436 . Registered on February 25, 2020.

Dose Dependent Effects of Breynia cernua Against the Paraquat Induced Parkinsonism like Symptoms in Animals' Model: In Vitro, In Vivo and Mechanistic Studies

The aims and objectives of the study were to evaluate the antiParkinson's (PD) potential of B cernua (BCE). B cernua (Poir.) Müll. Arg. (B cernua) is a member of the Phyllanthaceae family. HPLC revealed the presence of various phytochemicals. Study was conducted for 40 days. After PD induction by paraquat behavioural studies were carried out. Biochemical parameters such as DPPH, NO-scavenging, Ferrous reducing power, MDA, GSH, CAT, SOD, acetylcholinesterase (AChE), neurotransmitter estimation and TNF-α and IL-6 levels were determined. DPPH, NO-scavenging and Ferrous reducing power assays showed 78.02%, 48.05% and 71.45% inhibitions, respectively. There was significant improvement in motor functions and coordination in a dose-dependent manner (50 < 250 < 500 mg/kg) in PD rat model. Biochemical markers; SOD, CAT, GPx and GSH showed significant restoration (P < .001) while MDA showed significant decrease (P < .05). The AChE level was significantly reduced (P < .05) at 500 mg/kg while neurotransmitters were significantly improved (P < .001) in a dose-dependent fashion. The ELISA results showed significant (P < .001) down-regulation of IL-6 and TNF-α level. In conclusion, it is suggested that BCE has the potential to reduce the symptoms of PD.

Blueberry juice augments exercise-induced neuroprotection in a Parkinson's disease model through modulation of GDNF levels

Exercise and consumption of plant-based foods rich in polyphenols are attractive therapeutic approaches for the prevention and treatment of Parkinson's disease (PD). Few studies, however, have examined the neuroprotective efficacy of combining these treatment modalities against PD. Therefore we investigated whether combining voluntary running and consumption of blueberry juice (BBJ) was more efficacious against 6-hydroxydopamine (6-OHDA) toxicity than either treatment alone. Four weeks of running before and after intrastriatal 6-OHDA reduced amphetamine-induced rotational behavior and loss of substantia nigra dopamine (DA) neurons. BBJ consumption alone had no ameliorative effects, but when combined with exercise, behavioral deficits and nigrostriatal DA neurodegeneration were reduced to a greater extent than exercise alone. The neuroprotection observed with exercise alone was associated with an increase in striatal glial cell-lined derived neurotrophic factor (GDNF), whereas combining exercise and BBJ was associated with an increase in nigral GDNF. These results suggest that polyphenols may potentiate the protective effects of exercise and that differential regulation of GDNF expression underlies protection observed with exercise alone versus combined treatment with consumption of BBJ.

Aerobic Physical Exercise as a Non-medical Intervention for Brain Dysfunction: State of the Art and Beyond

Brain disorders, including stroke, Alzheimer's disease, depression, and chronic pain, are difficult to effectively treat. These major brain disorders have high incidence and mortality rates in the general population, and seriously affect not only the patient's quality of life, but also increases the burden of social medical care. Aerobic physical exercise is considered an effective adjuvant therapy for preventing and treating major brain disorders. Although the underlying regulatory mechanisms are still unknown, systemic processes may be involved. Here, this review aimed to reveal that aerobic physical exercise improved depression and several brain functions, including cognitive functions, and provided chronic pain relief. We concluded that aerobic physical exercise helps to maintain the regulatory mechanisms of brain homeostasis through anti-inflammatory mechanisms and enhanced synaptic plasticity and inhibition of hippocampal atrophy and neuronal apoptosis. In addition, we also discussed the cross-system mechanisms of aerobic exercise in regulating imbalances in brain function, such as the “bone-brain axis.” Furthermore, our findings provide a scientific basis for the clinical application of aerobic physical exercise in the fight against brain disorders.

Inhibition of Nigral Microglial Activation Reduces Age-Related Loss of Dopaminergic Neurons and Motor Deficits

Parkinson's disease (PD) is an age-related neurodegenerative disease caused by a selective loss of dopaminergic (DA) neurons in the substantia nigra (SN). Microglial activation is implicated in the pathogenesis of PD. This study aimed to characterize the role of microglial activation in aging-related nigral DA neuron loss and motor deficits in mice. We showed that, compared to 3-month-old mice, the number of DA neurons in the SN and the expression of dopamine transporter (DAT) in the striatum decreased during the period of 9 to 12 months of age. Motor deficits and microglial activation in the SN were also evident during these months. The number of DA neurons was negatively correlated with the degrees of microglial activation. The inhibition of age-related microglial activation by ibuprofen during these 3 months decreased DA neuron loss in the SN. Eliminating the microglia prevented systemic inflammation-induced DA neuron death. Forcing mice to run during these 3 months inhibited microglial activation and DA neuron loss. Blocking the brain-derived neurotrophic factor (BDNF) signaling eliminated the exercise-induced protective effects. In conclusion, nigral DA neurons were susceptible to local microglial activation. Running exercise upregulated BDNF-TrkB signaling and inhibited microglial activation during aging. Long-term exercise can be considered as a non-pharmacological strategy to ameliorate microglial activation and related neurodegeneration.

Unraveling the Neuroprotective Effect of Tinospora cordifolia in a Parkinsonian Mouse Model through the Proteomics Approach

Stress-induced dopaminergic (DAergic) neuronal death in the midbrain region is the primary cause of Parkinson's disease (PD). Following the discovery of l-dopa, multiple drugs have been developed to improve the lifestyle of PD patients; however, none have been suitable for clinical use due to their multiple side effects. Tinospora cordifolia has been used in traditional medicines to treat neurodegenerative diseases. Previously, we reported the neuroprotective role of Tc via inhibition of NF-κB-associated proinflammatory cytokines against MPTP-intoxicated Parkinsonian mice. In the present study, we investigated the neuroprotective molecular mechanism of Tc in a rotenone (ROT)-intoxicated mouse model, using a proteomics approach. Mice were pretreated with Tc extract by oral administration, followed by ROT intoxication. Behavioral tests were performed to check motor functions of mice. Protein was isolated, and label-free quantification (LFQ) was carried out to identify differentially expressed protein (DEP) in control vs PD and PD vs treatment groups. Results were validated by qRT-PCR with the expression of target genes correlating with the proteomics data. In this study, we report 800 DEPs in control vs PD and 133 in PD vs treatment groups. In silico tools demonstrate significant enrichment of biochemical and molecular pathways with DEPs, which are known to be important for PD progression including mitochondrial gene expression, PD pathways, TGF-β signaling, and Alzheimer's disease. This study provides novel insights into the PD progression as well as new therapeutic targets. More importantly, it demonstrates that Tc can exert therapeutic effects by regulating multiple pathways, resulting in neuroprotection.

Boxing vs Sensory Exercise for Parkinson's Disease: A Double-Blinded Randomized Controlled Trial

Background. Exercise is increasingly becoming recognized as an important adjunct to medications in the clinical management of Parkinson's disease (PD). Boxing and sensory exercise have shown immediate benefits, but whether they continue beyond program completion is unknown. This study aimed to investigate the effects of boxing and sensory training on motor symptoms of PD, and whether these benefits remain upon completion of the intervention. Methods. In this 20-week double-blinded randomized controlled trial, 40 participants with idiopathic PD were randomized into 2 treatment groups, (n = 20) boxing or (n = 20) sensory exercise. Participants completed 10 weeks of intervention. Motor symptoms were assessed at (week 0, 10, and 20) using the Unified Parkinson's Disease Rating Scale (UPDRS-III). Data were analyzed using SPSS, and repeated-measures ANOVA was conducted. Results. A significant interaction effect between groups and time were observed F(1, 39) = 4.566, P = .036, where the sensory group improved in comparison to the boxing group. Post hoc analysis revealed that in comparison to boxing, the effects of exercise did not wear off at washout (week 20) P < .006. Conclusion. Future rehabilitation research should incorporate similar measures to explore whether effects of exercise wear off post intervention.

Exercise Promotes Neurite Extensions from Grafted Dopaminergic Neurons in the Direction of the Dorsolateral Striatum in Parkinson's Disease Model Rats

Background:

Cell transplantation is expected to be a promising treatment for Parkinson’s disease (PD), in which re-innervation of the host striatum by grafted dopamine (DA) neurons is essential. In particular, the dorsolateral part of the striatum is important because it is the target of midbrain A9 DA neurons, which are degenerated in PD pathology. The effect of exercise on the survival and maturation of grafted neurons has been reported in several neurological disease models, but never in PD models.

Objective:

We investigated how exercise influences cell transplantation for PD, especially from the viewpoint of cell survival and neurite extensions.

Methods:

Ventral mesencephalic neurons from embryonic (E12.5) rats were transplanted into the striatum of adult 6-OHDA-lesioned rats. The host rats then underwent treadmill training as exercise after the transplantation. Six weeks after the transplantation, they were sacrificed, and the grafts in the striatum were analyzed.

Results:

The addition of exercise post-transplantation significantly increased the number of surviving DA neurons. Moreover, it promoted neurite extensions from the graft toward the dorsolateral part of the striatum.

Conclusions:

This study indicates a beneficial effect of exercise after cell transplantation in PD.

Rat Models of Vocal Deficits in Parkinson's Disease

Parkinson's disease (PD) is a progressive, degenerative disorder that affects 10 million people worldwide. More than 90% of individuals with PD develop hypokinetic dysarthria, a motor speech disorder that impairs vocal communication and quality of life. Despite the prevalence of vocal deficits in this population, very little is known about the pathological mechanisms underlying this aspect of disease. As such, effective treatment options are limited. Rat models have provided unique insights into the disease-specific mechanisms of vocal deficits in PD. This review summarizes recent studies investigating vocal deficits in 6-hydroxydopamine (6-OHDA), alpha-synuclein overexpression, DJ1-/-, and Pink1-/- rat models of PD. Model-specific changes to rat ultrasonic vocalization (USV), and the effects of exercise and pharmacologic interventions on USV production in these models are discussed.

Delayed Clinical Manifestation of Parkinson's Disease Among Physically Active: Do Participants in a Long-Distance Ski Race Have a Motor Reserve?

Background:

Physical activity is associated with reduced risk of Parkinson’s disease (PD). The explanations for this association are not completely elucidated. We use long-term PD-incidence data from long-distance skiers to study the relationship between exercise and PD.

Objective:

We aimed to investigate if physical activity is associated with long-term lower risk of PD and if this association could be explained by physically active people being able to sustain more PD neuropathology before clinical symptoms, a motor reserve.

Methods:

Using a prospective observational design, we studied whether long-distance skiers of the Swedish Vasaloppet (n = 197,685), exhibited reduced incidence of PD compared to matched individuals from the general population (n = 197,684) during 21 years of follow-up (median 10, interquartile range (IQR) 5–15 years).

Results:

Vasaloppet skiers (median age 36.0 years [IQR 29.0–46.0], 38% women) had lower incidence of PD (HR: 0.71; 95 % CI 0.56–0.90) compared to non-skiers. When reducing risk for reverse causation by excluding PD cases within the first five years from race participation, there was still a trend for lower risk of PD (HR: 0.80; 95 % CI 0.62–1.03). Further, the PD prevalence converged between skiers and non-skiers after 15 years of follow-up, which is more consistent with a motor reserve in the physically active rather than neuroprotection.

Conclusions:

A physical active lifestyle is associated with reduced risk for PD. This association weakens with time and might be explained by a motor reserve among the physically active.

Cymene consumption and physical activity effect in Alzheimer's disease model: an in vivo and in vitro study

Purpose

Alzheimer's disease (AD) is one of the most important neurodegenerative diseases and accompanied by the production of free radicals and inflammatory factors. Studies have shown that p-cymene has anti-inflammatory and anti-oxidant effects. Here, the effects of this compound were investigated on a rat model of AD.

Methods

In order to create Alzheimer's rat model, bilateral injection of Amyloid β1-42 (Aβ1-42) into rats hippocampus was performed. Both therapeutic (post-AD induction) and preventive effects of p-cymene consumption with doses of 50 and 100 mg/kg were investigated. In addition, the effects of adding short-term exercise to the process were also observed. In vitro, Aβ1-42 peptide was driven toward fibril formation and effect of p-cymene was observed on the resulting fibrils.

Results

Learning and memory indices in the AD rats were significantly reduced compared to the Sham group, while p-cymene consumption with both doses, as well as performing exercise counteracted AD consequences. Moreover, increased neurogenesis and reduced amyloid plaques counts were observed in treated rats. In vitro formed fibrils of Aβ1-42 were partially disaggregated in the presence of p-cymene.

Discussion

p-Cymene could act on this AD model via antioxidant and anti-inflammatory properties as well as direct anti-fibril effect.

Conclusion

p-cymene can improve AD-related disorders including memory impairment.

Cytokine-, Neurotrophin-, and Motor Rehabilitation-Induced Plasticity in Parkinson's Disease

Neuroinflammation and cytokine-dependent neurotoxicity appear to be major contributors to the neuropathology in Parkinson's disease (PD). While pharmacological advancements have been a mainstay in the treatment of PD for decades, it is becoming increasingly clear that nonpharmacological approaches including traditional and nontraditional forms of exercise and physical rehabilitation can be critical adjunctive or even primary treatment avenues. Here, we provide an overview of preclinical and clinical research detailing the biological role of proinflammatory molecules in PD and how motor rehabilitation can be used to therapeutically modulate neuroinflammation, restore neural plasticity, and improve motor function in PD.

A Mobile App Specifically Designed to Facilitate Exercise in Parkinson Disease: Single-Cohort Pilot Study on Feasibility, Safety, and Signal of Efficacy

Background

Many people with Parkinson disease do not have access to exercise programs that are specifically tailored to their needs and capabilities. This mobile app allows people with Parkinson disease to access Parkinson disease–specific exercises that are individually tailored using in-app demographic questions and performance tests which are fed into an algorithm which in turn produces a video-guided exercise program.

Objective

To test the feasibility, safety, and signal of efficacy of a mobile app that facilitates exercise for people with Parkinson disease.

Methods

A prospective, single-cohort design of people with Parkinson disease who had downloaded the 9zest app for exercise was used for this 12-week pilot study. Participants, who were recruited online, were encouraged to exercise with the full automated app for ≥150 minutes each week. The primary endpoints were feasibility (app usage and usability questions) and safety (adverse events and falls). The primary endpoints for signal of efficacy were a comparison of the in-app baseline and 8-week outcomes on the 30-second Sit-To-Stand (STS) test, Timed Up and Go (TUG) test, and the Parkinson’s Disease Questionnaire 8 (PDQ8).

Results

For feasibility, of the 28 participants that completed the study, 12 participants averaged >150 minutes of app usage per week (3 averaged 120-150, 4 averaged 90-120, and 9 averaged less than 90 minutes). A majority of participants (>74%) felt the exercise was of value (16/19; 9 nonrespondents), provided adequate instruction (14/19; 9 nonrespondents), and was appropriate for level of function (16/19; 9 nonrespondents). For safety, there were no serious adverse events that occurred during the app-guided exercise. There were 4 reports of strain/sprain injuries while using the app among 3 participants, none of which necessitated medical attention. For signal of efficacy, there was improvement for each of the primary endpoints: STS (P=.01), TUG (P<.001), and PDQ8 (P=.01).

Conclusions

Independent, video-guided exercise using a mobile app designed for exercise in Parkinson disease was safe and feasible though there was variability in app usage. Despite this, the results provide evidence for a signal of efficacy as there were improvements in 3 of the 3 outcomes.

Trial Registration

ClinicalTrials.gov NCT03459586; https://clinicaltrials.gov/ct2/show/NCT03459586

Effects of Regular Exercise on Diabetes-Induced Memory Deficits and Biochemical Parameters in Male Rats

The main objective of current work was to determine the effects of treadmill-running and swimming exercise on passive avoidance learning (PAL) and blood biochemical parameters in rats with streptozotocin (STZ)-induced diabetes. Male Wistar rats were divided into the following 6 groups (N = 6-8 per group): CON, healthy rats without exercise (N = 8); STZ, diabetic rats without exercise (N = 8); CON-SE, healthy rats subjected to swimming exercise (2 months; N = 6); STZ-SE, diabetic rats subjected to swimming exercise (2 months; N = 7); CON-TE, healthy rats subjected to treadmill exercise (2 months; N = 8); STZ-TE, diabetic rats subjected to treadmill exercise (2 months; N = 8). Diabetes was induced by a single intraperitoneal injection of 50 mg/kg STZ. Our results showed that STZ decreased the step-through latency in the retention test (STLr) and increased the time spent in the dark compartment (TDC) when compared with the CON group. However, treadmill-running and swimming exercise in STZ-treated rats increased the STLr and decreased the TDC when compared with STZ-treated rats without exercise in PAL. Blood low-density lipoprotein (LDL) and triglyceride (TG) levels in the STZ group were significantly higher than those in the CON group, whereas plasma total antioxidant capacity (TAC) and levels of catalase (CAT) and glutathione peroxidase (GPx) were lower in the STZ group compared with the CON group. The levels of LDL and TG decreased and the levels of TAC, CAT, and GPx increased in the exercise groups in comparison with the STZ group. The present results indicate that regular exercise enhances learning and memory in diabetic rats and that these effects may occur through activation of the antioxidant system.

A Ketone Ester Drink Enhances Endurance Exercise Performance in Parkinson's Disease

Objectives

Routine exercise is thought to be among the only disease-modifying treatments for Parkinson's disease; however, patients' progressive loss of physical ability limits its application. Therefore, we sought to investigate whether a ketone ester drink, which has previously been shown to enhance endurance exercise performance in elite athletes, could also improve performance in persons with Parkinson's disease.

Participants

14 patients, aged 40-80 years, with Hoehn and Yahr stage 1-2 Parkinson's disease.

Intervention

A randomized, placebo-controlled, crossover study in which each participant was administered a ketone ester drink or an isocaloric carbohydrate-based control drink on separate occasions prior to engaging in a steady state cycling test at 80 rpm to assess endurance exercise performance.

Outcomes Measures

The primary outcome variable was length of time participants could sustain a therapeutic 80 rpm cadence. Secondary, metabolic outcomes measures included cardiorespiratory parameters as well as serum β-hydroxybutyrate, glucose, and lactate.

Results

The ketone ester increased the time that participants were able to sustain an 80 rpm cycling cadence by 24 ± 9% (p = 0.027). Correspondingly, the ketone ester increased β-hydroxybutyrate levels to >3 mmol/L and decreased respiratory exchange ratio, consistent with a shift away from carbohydrate-dependent metabolism.

Conclusion

Ketone ester supplementation improved endurance exercise performance in persons with Parkinson's disease and may, therefore, be useful as an adjunctive therapy to enhance the effectiveness of exercise treatment for Parkinson's disease.

The Universal Prescription for Parkinson's Disease: Exercise

Over the past two decades, aerobic exercise has emerged as a mainstream recommendation to aid in treating Parkinson's disease (PD). Despite the acknowledgement of the benefits of exercise for people with PD (PwPD), frequently, exercise recommendations lack specificity in terms of frequency, intensity and duration. Additionally, conflating physical activity with exercise has contributed to providing vague exercise recommendations to PwPD. Therefore, the beneficial effects of exercise may not be fully realized in PwPD. Data provided by animal studies and select human trials indicate aerobic exercise may facilitate structural and functional changes in the brain. Recently, several large human clinical trials have been completed and collectively support the use of aerobic exercise, specifically high-intensity aerobic exercise, in improving PD motor symptoms. Data from these and other studies provide the basis to include aerobic exercise as an integral component in treating PD. Based on positive clinical findings and trials, it is advised that PwPD perform aerobic exercise in the following dose: 3x/week, 30-40-minute main exercise set, 60-80% of heart rate reserve or 70-85% of heart rate max. In lieu of heart rate, individuals can achieve an intensity of 14-17 on a 20-point RPE scale. Ongoing clinical trials, SPARX3 and CYCLE-II, have potential to further develop patient-specific exercise recommendations through prognostic modeling.

Exercise-Induced Neuroprotection in the 6-Hydroxydopamine Parkinson's Disease Model

Exercise exerts helpful effects in Parkinson's disease. In this study, the 6-hydroxydopamine (6-OHDA) injection was used to investigate the effect of exercise on apomorphine-induced rotation and neurorestoration. Rats (n = 32) were divided into four groups: (1) Saline+Noexercise (Sham); (2) 6-OHDA+Noexercise (6-OHDA); (3) Saline+Exercise (S+EXE), and (4) 6-OHDA+Exercise (6-OHDA+EXE). The rats were administered 8 μg 6-OHDA by injection into the right medial forebrain bundle. After 2 weeks, the exercise group was run (14 consecutive days, 30 min per day). One month after the surgery, following the injection of apomorphine, the 6-OHDA group displayed a significant increase in rotation and the 6-OHDA+EXE group showed a significant reduction of rotational asymmetry (P < 0.001). 6-OHDA injection reduced the mRNA and protein expression of the AMP-activated protein kinase, brain-derived neurotropic factor, and tyrosine hydroxylase in relation to the Sham group and exercise increased these levels. Expression of the silent information regulator 2 homolog 1 and peroxisome proliferator-activated receptor gamma coactivator 1-alpha was unexpectedly enhanced in the 6-OHDA groups in relation to the Sham group. These findings suggest that the 6-OHDA injection increased the neurodegeneration and mitochondrial and behavioral dysfunctions and the treadmill running attenuated these disorders in the ipsilateral striatum of the 6-OHDA+EXE group.

Effect of a High-Intensity Tandem Bicycle Exercise Program on Clinical Severity, Functional Magnetic Resonance Imaging, and Plasma Biomarkers in Parkinson's Disease

Rationale: The optimal modality, intensity, duration, frequency, and dose-response of exercise as a therapy for Parkinson's Disease (PD) are insufficiently understood. Objective: To assess the impact of a high-intensity tandem bicycle program on clinical severity, biomarkers, and functional MRI (fMRI) in PD. Methods: A single-center, parallel-group clinical trial was conducted. Thirteen PD patients aged 65 or younger were divided in two groups: a control group and an intervention group that incorporated a cycling program at 80% of each individual's maximum heart rate (HR) (≥80 rpm), three times a week, for 16 weeks. Both groups continued their conventional medications for PD. At baseline and at the end of follow-up, we determined in all participants the Unified Parkinson's Disease Rating Scale, anthropometry, VO₂max, PD biomarkers, and fMRI. Results: VO₂max improved in the intervention group (IG) (+5.7 ml/kg/min), while it slightly deteriorated in the control group (CG) (-1.6 ml/kg/min) (p = 0.041). Mean Unified Parkinson's Disease Rating Scale (UPDRS) went down by 5.7 points in the IG and showed a small 0.9-point increase in the CG (p = 0.11). fMRI showed activation of the right fusiform gyrus during the motor task and functional connectivity between the cingulum and areas of the frontal cortex, and between the cerebellar vermis and the thalamus and posterior temporal gyrus. Plasma brain-derived neurotrophic factor (BDNF) levels increased more than 10-fold in the IG and decreased in the CG (p = 0.028). Larger increases in plasma BDNF correlated with greater decreases in UPDRS (r = -0.58, p = 0.04). Conclusions: Our findings suggest that high-intensity tandem bicycle improves motor function and biochemical and functional neuroimaging variables in PD patients. Trial registration number: ISRCTN 13047118, Registered on February 8, 2018.

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.

Chasing Protection in Parkinson's Disease: Does Exercise Reduce Risk and Progression?

Exercise may be the most commonly offered yet least consistently followed therapeutic advice for people with Parkinson's disease (PD). Epidemiological studies of prospectively followed cohorts have shown a lower risk for later developing PD in healthy people who report moderate to high levels of physical activity, and slower rates of motor and non-motor symptom progression in people with PD who report higher baseline physical activity. In animal models of PD, exercise can reduce inflammation, decrease α-synuclein expression, reduce mitochondrial dysfunction, and increase neurotrophic growth factor expression. Randomized controlled trials of exercise in PD have provided clear evidence for short-term benefits on many PD measurements scales, ranging from disease severity to quality of life. In this review, we present these convergent epidemiological and laboratory data with particular attention to translationally relevant features of exercise (e.g., intensity requirements, gender differences, and associated biomarkers). In the context of these findings we will discuss clinical trial experience, design challenges, and emerging opportunities for determining whether exercise can prevent PD or slow its long-term progression.

How the enriched get richer? Experience-dependent modulation of microRNAs and the therapeutic effects of environmental enrichment

Environmental enrichment and physical exercise have many well-established health benefits. Although these environmental manipulations are known to delay symptom onset and progression in a variety of neurological and psychiatric conditions, the mechanisms underlying these effects remain poorly understood. A notable candidate molecular mechanism is that of microRNA, a family of small noncoding RNAs that are important regulators of gene expression. Research investigating the many diverse roles of microRNAs has greatly expanded over the past decade, with several promising preclinical and clinical studies highlighting the role of dysregulated microRNA expression (in the brain, blood and other peripheral systems) in understanding the aetiology of disease. Altered microRNA levels have also been described following environmental interventions such as exercise and environmental enrichment in non-clinical populations and wild-type animals, as well as in some brain disorders and associated preclinical models. Recent studies exploring the effects of stimulating environments on microRNA levels in the brain have revealed an array of changes that are likely to have important downstream effects on gene expression, and thus may regulate a variety of cellular processes. Here we review literature that explores the differential expression of microRNAs in rodents following environmental enrichment and exercise, in both healthy control animals and preclinical models of relevance to neurological and psychiatric disorders.

Guidelines for animal exercise and training protocols for cardiovascular studies

Whole body exercise tolerance is the consummate example of integrative physiological function among the metabolic, neuromuscular, cardiovascular, and respiratory systems. Depending on the animal selected, the energetic demands and flux through the oxygen transport system can increase two orders of magnitude from rest to maximal exercise. Thus, animal models in health and disease present the scientist with flexible, powerful, and, in some instances, purpose-built tools to explore the mechanistic bases for physiological function and help unveil the causes for pathological or age-related exercise intolerance. Elegant experimental designs and analyses of kinetic parameters and steady-state responses permit acute and chronic exercise paradigms to identify therapeutic targets for drug development in disease and also present the opportunity to test the efficacy of pharmacological and behavioral countermeasures during aging, for example. However, for this promise to be fully realized, the correct or optimal animal model must be selected in conjunction with reproducible tests of physiological function (e.g., exercise capacity and maximal oxygen uptake) that can be compared equitably across laboratories, clinics, and other proving grounds. Rigorously controlled animal exercise and training studies constitute the foundation of translational research. This review presents the most commonly selected animal models with guidelines for their use and obtaining reproducible results and, crucially, translates state-of-the-art techniques and procedures developed on humans to those animal models.

The therapeutic potential of exercise for neuropsychiatric diseases: A review

Exercise is known to have a myriad of health benefits. There is much to be learned from the effects of exercise and its potential for prevention, attenuation and treatment of multiple neuropsychiatric diseases and behavioral disorders. Furthermore, recent data and research on exercise benefits with respect to major health crises, such as, that of opioid and general substance use disorders, make it very important to better understand and review the mechanisms of exercise and how it could be utilized for effective treatments or adjunct treatments for these diseases. In addition, mechanisms, epigenetics and sex differences are examined and discussed in terms of future research implications.

Geriatric Rehabilitation: Gait in the Elderly, Fall Prevention and Parkinson Disease

Aging-associated anatomic and physiologic decline begins during the fourth decade of life and progresses over the ensuing decades sometimes to a state of frailty, with the decline amplified when there is deconditioning. Aging-related gait and balance disorders leading to an increased risk of falling can be compensated for with the use of exercise interventions, durable medical equipment, and environmental modifications. Caregiver training is an essential component of geriatric rehabilitation.

The effect of preventive exercise on the neuroprotection in 6-hydroxydopamine-lesioned rat brain

Parkinson's disease is characterized by neurodegeneration and learning deficiency. Physical exercise can alleviate these symptoms by increasing the expression of some effective and relevant factors. The preventive effect of 16-week treadmill running in a rat model of Parkinson's disease, before 6-hydroxydopamine (6-OHDA) induction, was assessed. Experimental groups consisted of sedentary (SED), SED+6-OHDA, exercised (EX), and EX+6-OHDA rats. Forty-eight hours after the last session of exercise, 6-OHDA was injected into the medial forebrain bundle (MFB). One week after the injection, behavioral tests, including spatial learning and memory, were assessed through Morris water maze (MWM) and apomorphine-induced rotation. Three weeks after the injection, mRNA expression and protein levels of the transcriptional co-activator peroxisome-proliferator-activated receptor-γ co-activator-1α (PGC-1α), fibronectin type III domain-containing protein 5 (FNDC5), brain-derived neurotrophic factor (BDNF), and tyrosine hydroxylase (TH) were measured in the striatum and the hippocampus of rats by applying real-time PCR and Western blotting. The findings indicate that exposure to 6-OHDA leads to impairments in behavioral and molecular functions. Exercise training prevents and reduces the symptoms caused by dopamine toxins. The results suggest that treadmill running can exert neuroprotective and have preventive effects to reduce Parkinson's disease symptoms. Novelty Parkinson's disease impairs spatial learning and memory. Parkinson's disease reduced levels of PGC-1α, FNDC5, and BDNF and increased neurodegeneration in the striatum and the hippocampus. Treadmill running before disease attenuated 6-OHDA-induced memory deficit and elevated neuroprotection. Exercise has multiple effects on memory and biochemical factors.

Exercise-Induced Neuroprotection and Recovery of Motor Function in Animal Models of Parkinson's Disease

Parkinson's disease (PD) is manifested by progressive motor, autonomic, and cognitive disturbances. Dopamine (DA) synthesizing neurons in the substantia nigra (SN) degenerate, causing a decline in DA level in the striatum that leads to the characteristic movement disorders. A disease-modifying therapy to arrest PD progression remains unattainable with current pharmacotherapies, most of which cause severe side effects and lose their efficacy with time. For this reason, there is a need to seek new therapies supporting the pharmacological treatment of PD. Motor therapy is recommended for pharmacologically treated PD patients as it alleviates the symptoms. Molecular mechanisms behind the beneficial effects of motor therapy are unknown, nor is it known whether such therapy may be neuroprotective in PD patients. Due to obvious limitations, human studies are unlikely to answer these questions; therefore, the use of animal models of PD seems indispensable. Motor therapy in animal models of PD characterized by the loss of dopaminergic neurons has neuroprotective and neuroregenerative effects, and the completeness of neuronal protection may depend on (i) degree of neuronal loss, (ii) duration and intensity of exercise, and (iii) time elapsed between insult and commencing of training. As the physical activity is neuroprotective for dopaminergic neurons, the question arises what is the mechanism of this protective action. A current hypothesis assumes a central role of neurotrophic factors in the neuroprotection of dopaminergic neurons, even though it is still not clear whether increased DA level in the nigrostriatal axis results from neurogenesis of dopaminergic neurons in the SN, recovery of the phenotype of dopaminergic neurons, increased sprouting of the residual dopaminergic axons in the striatum, or generation of local striatal neurons from inhibitory interneurons. In the present review, we discuss studies describing the influence of physical exercise on the PD-like changes manifested in animal models of the disease and focus our interest on the current state of knowledge on the mechanism of neuroprotection induced by physical activity as a supportive therapy in PD.

The effects of moderate exercise and overtraining on learning and memory, hippocampal inflammatory cytokine levels, and brain oxidative stress markers in rats

To investigate the exercise intensity effects on rats' memory and learning, animals were divided into control, moderate training (MT), and overtraining (OT) groups. At training last week, learning and memory was assessed using Morris water maze (MWM) and passive avoidance (PA) tests. Finally, the rat's brains were removed for evaluating oxidative stress and inflammatory cytokines. Overtraining impaired animal's performance in MWM and PA tests. In MT group, hippocampal levels of interleukin 1 beta (IL-1β) and malondialdehyde (MDA) increased, and thiol contents in hippocampal and cortical tissues decreased compared to control. In OT group, tumor necrosis factor α, IL-1β, and C-reactive protein hippocampal levels increased, MDA and nitric oxide metabolite in hippocampal and cortical tissues increased, thiol contents, catalase and superoxide dismutase activity in hippocampal and cortical tissues decreased compared to control and MT groups. Overtraining might lead to learning and memory impairment by increasing the inflammatory cytokine and oxidative stress markers.

GFR-α1 Expression in Substantia Nigra Increases Bilaterally Following Unilateral Striatal GDNF in Aged Rats and Attenuates Nigral Tyrosine Hydroxylase Loss Following 6-OHDA Nigrostriatal Lesion

Glial cell line-derived neurotrophic factor (GDNF) improved motor function in Parkinson's disease (PD) patients in Phase I clinical trials, and these effects persisted months after GDNF discontinuation. Conversely, phase II clinical trials reported no significant effects on motor improvement vs placebo. The disease duration and the quantity, infusion approach, and duration of GDNF delivery may affect GDNF efficacy in PD treatment. However, identifying mechanisms activated by GDNF that affect nigrostriatal function may reveal additional avenues to partially restore nigrostriatal function. In PD and aging models, GDNF affects tyrosine hydroxylase (TH) expression or phosphorylation in substantia nigra (SN), long after a single GDNF injection in striatum. In aged rats, the GDNF family receptor, GFR-α1, increases TH expression and phosphorylation in SN. To determine if GFR-α1 could be a mechanistic link in long-term GDNF impact, we conducted two studies; first to determine if a single unilateral striatal delivery of GDNF affected GFR-α1 and TH over time (1 day, 1 week, and 4 weeks) in the striatum or SN in aged rats, and second, to determine if soluble GFR-α1 could mitigate TH loss following 6-hydroxydopamine (6-OHDA) lesion. In aged rats, GDNF bilaterally increased ser31 TH phosphorylation and GFR-α1 expression in SN at 1 day and 4 weeks after GDNF, respectively. In striatum, GFR-α1 expression decreased 1 week after GDNF, only on the GDNF-injected side. In 6-OHDA-lesioned rats, recombinant soluble GFR-α1 mitigated nigral, but not striatal, TH protein loss following 6-OHDA. Together, these results show GDNF has immediate and long-term impact on dopamine regulation in the SN, which includes a gradual increase in GFR-α1 expression that may sustain TH expression and dopamine function therein.

Functional and Brain Activation Changes Following Specialized Upper-Limb Exercise in Parkinson's Disease

For the management of Parkinson's disease (PD), the concept of forced exercise (FE) has drawn interest. In PD subjects, the FE executed with lower limbs has been shown to lessen symptoms and to promote brain adaptive changes. Our study is aimed to investigate the effect of an upper-limb exercise, conceptually comparable with the FE, in PD. Upper-limb exercise was achieved in a sitting position by using a specially designed device (Angel's Wings^®). Clinical data, computerized dynamic posturography, magnetic resonance imaging (MRI) (resting-state MRI and arterial spin labeling), and neuropsychological tests were used before and after 2 months' exercise training. We found a significant long-lasting improvement in Unified Parkinson Disease Rating Scale (UPDRS)-III and cognitive scales, along with improvement in balance and postural control (better alignment of the gravity center and improvement in weight symmetry and in anticipatory motor strategies). Computerized dynamic posturography pointed out an enhanced central ability to integrate the vestibular signals with afferents from other sensory systems. Neuroimaging analyses after 2 months' exercise training showed, with respect to pretraining condition, many changes. An increase of the cerebral blood flow was evident in the left primary motor cortex (M1), left supplementary motor cortical area, and left cerebellar cortex. The bilateral globus pallidus showed an increased functional connectivity to the right central operculum, right posterior cingulate gyrus, and left sensorimotor cortex. Seed-to-voxel analysis demonstrated a functional connectivity between M1 and the left superior frontal gyrus. Left crus II showed strengthened connections with the left pre-rolandic area, left post-rolandic area, and left supramarginal area. These findings likely reflect compensatory mechanisms to the neuropathological hallmark of PD. Overall, our results show that this upper-limb exercise model, conceptually comparable with the FE already tested in the lower limbs, leads to a global improvement (involving non-exercised limbs) likely consistent with the functional changes observed in the central nervous system.

Corneal Nerve Migration Rate in a Healthy Control Population

PURPOSE

The purpose of this study was to establish an age-dependent normative range and factors affecting the migration rate of the corneal subbasal nerve plexus in a healthy control population.

METHODS

Corneal nerve migration rate was measured in 60 healthy participants grouped by age: A, aged 20 to 39 years (n = 20); B, 40 to 59 years (n = 20); and C, 60 to 79 years (n = 20). Laser-scanning corneal confocal microscopy was performed on the right eye of all participants at baseline and again after 3 weeks. Fully automated software was used to montage the frames. Distinctive nerve landmarks were manually reidentified between the two montages, and a software program was developed to measure the migration of these landmark points to determine corneal nerve migration rate in micrometers per week (μm/wk).

RESULTS

The mean ± SD age of all participants in the study was 47.5 ± 15.5 years; 62% of participants were male. The average corneal nerve migration rates of groups A, B, and C were 42.0 ± 14.0, 42.3 ± 15.5, and 42.0 ± 10.8 μm/wk, respectively (P = .99). There was no difference in corneal nerve migration rate between male (41.1 ± 13.5 μm/wk) and female (43.7 ± 13.2 μm/wk) participants (P = .47). There was no significant correlation between age (P = .97), smoking (P = .46), alcohol use (P = .61), and body mass index (P = .49, respectively) with corneal nerve migration rate. However, exercise frequency correlated significantly (P = .04) with corneal nerve migration rate.

CONCLUSIONS

Corneal nerve migration rate varies in healthy individuals and is not affected by age, sex, or body mass index but is related to physical activity.

Physical activity sustains memory retrieval in dopamine-depleted mice previously treated with L-Dopa

The neurodegenerative disorder Parkinson's disease affects motor abilities as well as cognition. The gold standard therapy is L-Dopa, which mainly restores motor skills. Therefore, we require additional interventions to sustain cognitive functions in Parkinson's disease. The lifestyle intervention "physical activity" improves adult hippocampal neurogenesis and memory but so far, its impact has not been investigated in rodent models for Parkinson's disease previously treated with the standard therapy. We hereby asked whether physical activity serves as a pro-neurogenic and -cognitive stimulus in dopamine-depleted mice previously treated with L-Dopa. Therefore, we injected dopamine-depleted mice with L-Dopa/Benserazide followed either by exercise or by a sedentary lifestyle. We analysed adult hippocampal neurogenesis histologically and assessed spatial memory in the Morris water maze. Furthermore, we investigated the hippocampal and striatal monoaminergic cross-talk. Physical activity prevented memory decline and was linked to a slower dopamine turnover but did not enhance neurogenesis in dopamine-depleted mice previously treated with L-Dopa. In conclusion, physical activity did not develop its full pro-neurogenic potential in mice previously treated with L-Dopa but sustained spatial cognition in Parkinson's disease.