Motor Performance Improved by Exercises in Cerebral Ischemic Rats

Exercise-with-melatonin therapy improves sleep disorder and motor dysfunction in a rat model of ischemic stroke

JOURNAL/nrgr/04.03/01300535-202406000-00038/inline-graphic1/v/2023-10-30T152229Z/r/image-tiff

Exercise-with-melatonin therapy has complementary and synergistic effects on spinal cord injury and Alzheimer’s disease, but its effect on stroke is still poorly understood. In this study, we established a rat model of ischemic stroke by occluding the middle cerebral artery for 60 minutes. We treated the rats with exercise and melatonin therapy for 7 consecutive days. Results showed that exercise-with-melatonin therapy significantly prolonged sleep duration in the model rats, increased delta power values, and regularized delta power rhythm. Additionally, exercise-with-melatonin therapy improved coordination, endurance, and grip strength, as well as learning and memory abilities. At the same time, it led to higher hippocampal CA1 neuron activity and postsynaptic density thickness and lower expression of glutamate receptor 2 than did exercise or melatonin therapy alone. These findings suggest that exercise-with-melatonin therapy can alleviate sleep disorder and motor dysfunction by increasing glutamate receptor 2 protein expression and regulating hippocampal CA1 synaptic plasticity.

A review of remote ischemic conditioning as a potential strategy for neural repair poststroke

Ischemic stroke is one of the major disabling health-care problem and multiple different approaches are needed to enhance rehabilitation, in which neural repair is the structural basement. Remote ischemic conditioning (RIC) is a strategy to trigger endogenous protect. RIC has been reported to play neuroprotective role in acute stage of stroke, but the effect of RIC on repair process remaining unclear. Several studies have discovered some overlapped mechanisms RIC and neural repair performs. This review provides a hypothesis that RIC is a potential therapeutic strategy on stroke rehabilitation by evaluating the existing evidence and puts forward some remaining questions to clarify and future researches to be performed in the field.

Effect of cycling exercise on motor excitability and gait abnormalities in stroke patients

Background

The concepts of brain excitability are still re-wiring in response to changes in environment. Ambulation is often limited in stroke patients.

Objective

To determine the effect of cycling exercise on motor excitability and consequences on spatiotemporal gait parameters in stroke patients.

Methods

Forty male ischemic stroke patients were included; their age ranged from 45 to 60 years. The patients were assigned into two equal groups: control group (GI) and study group (GII). The GI is treated by a design physical therapy program in the form of task-oriented progressive resistance exercise for lower limb muscles, and the GII is treated by the same program in addition to cycling exercise for 30 min. Treatment was conducted three times per week for 10 weeks. The excitability over motor area (Cz) was assessed by the quantitative electroencephalogram (QEEG). The spatiotemporal gait parameters were assessed by the Biodex Gait Trainer 2TM.

Results

There was a significant increase of speed, step cycle, and step length of the affected side (P < 0.05) and a non-significant difference of step length of the non-affected side in the study group compared with that of the control group (P > 0.05). There was a significant increase of excitability over motor area (Cz) in the study group compared with that of the control group (P < 0.05).

Conclusion

Cycling exercise has a positive effect on excitability over motor area of lower limbs and can improve gait parameters in stroke patients.

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

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

Aerobic exercise attenuates neurodegeneration and promotes functional recovery - Why it matters for neurorehabilitation & neural repair

Aerobic exercise facilitates optimal neurological function and exerts beneficial effects in neurologic injuries. Both animal and clinical studies have shown that aerobic exercise reduces brain lesion volume and improves multiple aspects of cognition and motor function after stroke. Studies using animal models have proposed a wide range of potential molecular mechanisms that underlie the neurological benefits of aerobic exercise. Furthermore, additional exercise parameters, including time of initiation, exercise dosage (exercise duration and intensity), and treatment modality are also critical for clinical application, as identifying the optimal combination of parameters will afford patients with maximal functional gains. To clarify these issues, the current review summarizes the known neurological benefits of aerobic exercise under both physiological and pathological conditions and then considers the molecular mechanisms underlying these benefits in the contexts of stroke-like focal cerebral ischemia and cardiac arrest-induced global cerebral ischemia. In addition, we explore the key roles of exercise parameters on the extent of aerobic exercise-induced neurological benefits to elucidate the optimal combination for aerobic exercise intervention. Finally, the current challenges for aerobic exercise implementation after stroke are discussed.

Effects of combined electroacupuncture and exercise training on motor function and microtubule-associated protein 2 expression in the middle and late stages of cerebral infarction in rats

OBJECTIVE

To evaluate the effects of electroacupuncture (EA) combined with exercise training on motor function and microtubule-associated protein (MAP)-2 in the hippocampal CA3 region of rats in the middle and late stages of cerebral infarction, and explore potential underlying mechanisms of action.

METHODS

A total of 80 Wistar rats were randomly divided into model, EA, training and EA + training groups (n = 20 per group) after establishing the middle cerebral artery occlusion (MCAO) model of cerebral infarction. Rats were treated with EA and/or training in the sixth week post-MCAO. After receiving 2 weeks of treatment, motor function was assessed and MAP-2 expression in the CA3 region was measured using an immunohistochemical method.

RESULTS

Compared to the model group, significant differences in walking stick, balance beam and screen capture ability were detected in the EA, training and EA + training groups (p < 0.05). The EA + training group showed greater improvements than the EA and training groups (p < 0.05 each). Significant differences in MAP-2 expression were detected in the EA, training and EA + training groups compared to the model group (p < 0.05). MAP-2 expression was higher in the EA + training group than in the EA and training groups (p < 0.05 each).

CONCLUSION

MAP-2 expression and motor functional recovery were higher in the combined therapy (EA + training) group compared to the monotherapy (EA or training) groups. EA combined with exercise training appeared to significantly promote the recovery of motor function in the middle and late stages of cerebral infarction in this rat model.

Effects of physical exercise on skeletal muscles of rats with cerebral ischemia

Physical exercise is a known preventive and therapeutic alternative for several cerebrovascular diseases. Therefore, the objective of the present study was to evaluate the motor performance and histomorphometry of the biceps brachii, soleus, and tibialis anterior muscles of rats submitted to a treadmill training program prior to the induction of cerebral ischemia via occlusion of the middle cerebral artery (OMCA). A total of 24 Wistar rats were distributed into four groups: Sham-Sed: sedentary control animals (n=6), who underwent sham surgery (in which OMCA did not occur); Sham+Ex: control animals exercised before the sham surgery (n=6); I-Sed: sedentary animals with cerebral ischemia (n=6); and I+Ex: animals exercised before the induction of ischemia (n=6). The physical exercise consisted of treadmill training for five weeks, 30 min/day (5 days/week), at a speed of 14 m/min. The results showed that the type-I fibers presented greater fiber area in the exercised ischemic group (I+Ex: 2347.96±202.77 µm2) compared to the other groups (Sham-Sed: 1676.46±132.21 µm2; Sham+Ex: 1647.63±191.09 µm2; I+Ex: 1566.93±185.09 µm2; P=0.0002). Our findings suggested that the angiogenesis process may have influenced muscle recovery and reduced muscle atrophy of type-I fibers in the animals that exercised before cerebral ischemia.

Exposure to female estrous is beneficial for male mice against transient ischemic stroke

OBJECTIVE

Exposure to female estrous, a natural rewarding experience, alleviates anxiety and depression, and the contribution of this behavior to stroke outcome is unknown. The aim of this study was to evaluate whether exposure to female estrous is beneficial to recovery following transient ischemic stroke in male mice.

METHODS

Cerebral ischemia was induced in male ICR mice with thread occlusion of the middle cerebral artery (MCAO) for 30 min followed by reperfusion. MCAO mice were randomly divided into MCAO group and Estrous Female Exposure (EFE) group. The mice in the EFE group were subjected to estrous female mouse interaction from day 1 until the end of the experiment. Mortality was recorded during the investigation. Behavioral functions were assessed by a beam-walking test and corner test from day 1 to day 10 after MCAO. Serum testosterone levels were analyzed with ELISA, and the expression levels of growth-associated protein-43 (GAP-43) and synaptophysin in the cortex of the ischemic hemisphere were determined by western blot on day 7 after MCAO.

RESULTS

Exposure to female estrous reduced the mortality induced by cerebral ischemic lesions. The beam-walking test demonstrated that exposure to female estrous significantly improved motor function recovery. The serum testosterone levels and ischemic cortex GAP-43 expression were significantly higher in MCAO male mice exposed to female estrous.

CONCLUSION

Exposure to female estrous reduces mortality and improves functional recovery in MCAO male mice. The study provides the first evidence to support the importance of female interaction to male stroke rehabilitation.

ABBREVIATIONS

GAP-43: growth-associated protein-43; SYP: Synaptophysin; MCAO: middle cerebral artery occlusion; OVXs: ovariectomies; CCA: common carotid artery; ECA: external carotid artery; EFE: estrous female exposure; TTC: 2,3,5-triphenyltetrazolium chloride; PAGE: polyacrylamide gel electrophoresis; PVDF: polyvinylidene difluoride; ANOVA: analysis of variance; LSD: least significant difference.

Effects of treadmill exercise on cerebral angiogenesis and MT1-MMP expression after cerebral ischemia in rats

INTRODUCTION

Despite the increased understanding of treadmill training on angiogenesis of stroke patients, its mechanism is not clearly known. The metalloproteinase membrane type 1-metalloprotease (MT1-MMP) promotes the regeneration of the peripheral vessels but seldom research on the regeneration of cerebral blood vessels. This study was designed to investigate the effects of treadmill exercise on angiogenesis and MT1-MMP expression after cerebral ischemia in rats.

METHODS

The adult male Sprague Dawley(SD) rats were randomly divided into three groups: sham operation group, the middle cerebral artery occlusion group(MCAO) and middle cerebral artery occlusion group(MCAO)+exercise group. In 4d, 7d or 14d after MCAO, respectively, the rats' neurological function was evaluated by the modified neurologic severity scores (mNSS); the microvessel numbers in areas surrounding cerebral ischemia were counted with Microvessel Density(MVD)analysis; the levels of MT1-MMP and reversion-inducing cysteine-rich protein with Kazalmotifs (RECK) were detected by Western-blot and immunohistochemical method.

RESULTS

Compared with MCAO group, the number of capillaries and the level of MT1-MMP expression around the area of cerebral ischemia were significantly increased in each exercise group (p < 0.05), while the level of RECK expression and the scores of mNSS in each exercise group were significantly decreased (p < 0.05).

CONCLUSION

This study suggested that treadmill exercise training can significantly promote angiogenesis and improve neurological function after cerebral ischemia. Its mechanism may be related to the upgraduation of the MT1-MMP expression in brain microvessels surrounding area of the ischemic rat.

Is Environmental Enrichment Ready for Clinical Application in Human Post-stroke Rehabilitation?

Environmental enrichment (EE) has been widely used as a means to enhance brain plasticity mechanisms (e.g., increased dendritic branching, synaptogenesis, etc.) and improve behavioral function in both normal and brain-damaged animals. In spite of the demonstrated efficacy of EE for enhancing brain plasticity, it has largely remained a laboratory phenomenon with little translation to the clinical setting. Impediments to the implementation of enrichment as an intervention for human stroke rehabilitation and a lack of clinical translation can be attributed to a number of factors not limited to: (i) concerns that EE is actually the "normal state" for animals, whereas standard housing is a form of impoverishment; (ii) difficulty in standardizing EE conditions across clinical sites; (iii) the exact mechanisms underlying the beneficial actions of enrichment are largely correlative in nature; (iv) a lack of knowledge concerning what aspects of enrichment (e.g., exercise, socialization, cognitive stimulation) represent the critical or active ingredients for enhancing brain plasticity; and (v) the required "dose" of enrichment is unknown, since most laboratory studies employ continuous periods of enrichment, a condition that most clinicians view as impractical. In this review article, we summarize preclinical stroke recovery studies that have successfully utilized EE to promote functional recovery and highlight the potential underlying mechanisms. Subsequently, we discuss how EE is being applied in a clinical setting and address differences in preclinical and clinical EE work to date. It is argued that the best way forward is through the careful alignment of preclinical and clinical rehabilitation research. A combination of both approaches will allow research to fully address gaps in knowledge and facilitate the implementation of EE to the clinical setting.

Physical exercise promotes proliferation and differentiation of endogenous neural stem cells via ERK in rats with cerebral infarction

Physical exercise is beneficial for the functional recovery of neurons after stroke. It has been suggested that exercise regulates proliferation and differentiation of endogenous neural stem cells (NSCs); however, the underlying molecular mechanisms are still largely unknown. In the present study, the aim was to investigate whether physical exercise activates the extracellular signal-regulated kinase (ERK) signaling pathway to promote proliferation and differentiation of NSCs in rats with cerebral infarction, thereby improving neurological function. Following middle cerebral artery occlusion, rats underwent physical exercise and neurological behavior was analyzed at various time points. Immunofluorescence staining was performed to detect proliferation and differentiation of NSCs, and western blotting was used to analyze cyclin-dependent kinase 4 (CDK4), Cyclin D1, retinoblastoma protein (p-Rb), P-16, phosphorylated (p)-ERK1/2 and c-Fos expression. The results indicated that physical exercise promoted proliferation and differentiation of NSCs, and led to improved neural function. In addition, the expression levels of CDK4, Cyclin D1, p-Rb, p-ERK1/2 and c-Fos were upregulated, whereas the expression of P-16 was downregulated following exercise. U0126, an inhibitor of ERK signaling, reversed the beneficial effects of exercise. Therefore, it may be hypothesized that physical exercise enhances proliferation and differentiation of endogenous NSCs in the hippocampus of rats with cerebral infarction via the ERK signaling pathway.

Continuous and not continuous 2-week treadmill training enhances the performance in the passive avoidance test in ischemic gerbils

This study aims to investigate the frequency and total duration effects of the 2-week treadmill training after experimental ischemic stroke in the passive avoidance test. We performed bilateral occlusion of common external carotid arteries, for five minutes, in Mongolian gerbils. The training groups were: continuous training for twelve consecutive days or not continuous training for six non-consecutive days. The groups remained in the treadmill for 15min, with the speed set at 10m/min, and the training started 24h after the stroke. In the Shuttle Box, each animal had ten trials during the Learning Session (LS), which occurred 24h before the stroke. The Retention Test (RT) occurred 24h after the stroke and started on the second, third, seventh and twelfth day after LS. After the experiments, the brains were perfused, and coronal sections of the CA1 area of the hippocampus were cut and stained with hematoxylin and eosin. ANOVA on Ranks was used for Behavioral data analysis and morphological data by percentage. Ischemic training groups showed preservation in neuron density in the CA1 area of the hippocampus, when compared to the control groups. Animals subjected to continuous training, showed a higher latency in the RT when compared to ischemic animals in both weeks [(2nd, H=39.81; P<0.05), (3rd, H=38.08; P<0.05), (7th, H=44.17; P<0.05), and (12th, H=39.55; P<0.05). Animals in the not continuous training showed higher latency in the RT, in the second week only [(2nd, H=39.81; P<0.05), (3rd, H=38.08; P<0.05), (7th, H=44.17; P<0.05), and (12th, H=39.55; P<0.05). These findings suggest that improvement of memory after stroke after treadmill training is dependent on the frequency and total duration of training.

Defining Optimal Aerobic Exercise Parameters to Affect Complex Motor and Cognitive Outcomes after Stroke: A Systematic Review and Synthesis

Although poststroke aerobic exercise (AE) increases markers of neuroplasticity and protects perilesional tissue, the degree to which it enhances complex motor or cognitive outcomes is unknown. Previous research suggests that timing and dosage of exercise may be important. We synthesized data from clinical and animal studies in order to determine optimal AE training parameters and recovery outcomes for future research. Using predefined criteria, we included clinical trials of stroke of any type or duration and animal studies employing any established models of stroke. Of the 5,259 titles returned, 52 articles met our criteria, measuring the effects of AE on balance, lower extremity coordination, upper limb motor skills, learning, processing speed, memory, and executive function. We found that early-initiated low-to-moderate intensity AE improved locomotor coordination in rodents. In clinical trials, AE improved balance and lower limb coordination irrespective of intervention modality or parameter. In contrast, fine upper limb recovery was relatively resistant to AE. In terms of cognitive outcomes, poststroke AE in animals improved memory and learning, except when training was too intense. However, in clinical trials, combined training protocols more consistently improved cognition. We noted a paucity of studies examining the benefits of AE on recovery beyond cessation of the intervention.

Neuroprotection of Early Locomotor Exercise Poststroke: Evidence From Animal Studies

Early locomotor exercise after stroke has attracted a great deal of attention in clinical and animal research in recent years. A series of animal studies showed that early locomotor exercise poststroke could protect against ischemic brain injury and improve functional outcomes through the promotion of angiogenesis, inhibition of acute inflammatory response and neuron apoptosis, and protection of the blood-brain barrier. However, to date, the clinical application of early locomotor exercise poststroke was limited because some clinicians have little confidence in its effectiveness. Here we review the current progress of early locomotor exercise poststroke in animal models. We hope that a comprehensive awareness of the early locomotor exercise poststroke may help to implement early locomotor exercise more appropriately in treatment for ischemic stroke.

Aerobic exercise effects on neuroprotection and brain repair following stroke: a systematic review and perspective

Aerobic exercise (AE) enhances neuroplasticity and improves functional outcome in animal models of stroke, however the optimal parameters (days post-stroke, intensity, mode, and duration) to influence brain repair processes are not known. We searched PubMed, CINAHL, PsychInfo, the Cochrane Library, and the Central Register of Controlled Clinical Trials, using predefined criteria, including all years up to July 2013 (English language only). Clinical studies were included if participants had experienced an ischemic or hemorrhagic stroke. We included animal studies that utilized any method of global or focal ischemic stroke or intracerebral hemorrhage. Any intervention utilizing AE-based activity with the intention of improving cardiorespiratory fitness was included. Of the 4250 titles returned, 47 studies (all in animal models) met criteria and measured the effects of exercise on brain repair parameters (lesion volume, oxidative damage, inflammation and cell death, neurogenesis, angiogenesis and markers of stress). Our synthesized findings show that early-initiated (24-48h post-stroke) moderate forced exercise (10m/min, 5-7 days per week for about 30min) reduced lesion volume and protected perilesional tissue against oxidative damage and inflammation at least for the short term (4 weeks). The applicability and translation of experimental exercise paradigms to clinical trials are discussed.

Physical exercise training and neurovascular unit in ischemic stroke

Physical exercise could exert a neuroprotective effect in both clinical studies and animal experiments. A series of related studies have indicated that physical exercise could reduce infarct volume, alleviate neurological deficits, decrease blood-brain barrier dysfunction, promote angiogenesis in cerebral vascular system and increase the survival rate after ischemic stroke. In this review, we summarized the protective effects of physical exercise on neurovascular unit (NVU), including neurons, astrocytes, pericytes and the extracellular matrix. Furthermore, it was demonstrated that exercise training could decrease the blood-brain barrier dysfunction and promote angiogenesis in cerebral vascular system. An awareness of the exercise intervention benefits pre- and post stroke may lead more stroke patients and people with high-risk factors to accept exercise therapy for the prevention and treatment of stroke.

Acute neuromuscular adaptation at the spinal level following middle cerebral artery occlusion-reperfusion in the rat

The purpose of the study was to highlight the acute motor reflex adaptation and to deepen functional deficits following a middle cerebral artery occlusion-reperfusion (MCAO-r). Thirty-six Sprague-Dawley rats were included in this study. The middle cerebral artery occlusion (MCAO; 120 min) was performed on 16 rats studied at 1 and 7 days, respectively (MCAO-D1 and MCAO-D7, n = 8 for each group). The other animals were divided into 3 groups: SHAM-D1 (n = 6), SHAM-D7 (n = 6) and Control (n = 8). Rats performed 4 behavioral tests (the elevated body swing test, the beam balance test, the ladder-climbing test and the forelimb grip force) before the surgery and daily after MCAO-r. H-reflex on triceps brachii was measured before and after isometric exercise. Infarction size and cerebral edema were respectively assessed by histological (Cresyl violet) and MRI measurements at the same time points than H-reflex recordings. Animals with cerebral ischemia showed persistent functional deficits during the first week post-MCAO-r. H-reflex was not decreased in response to isometric exercise one day after the cerebral ischemia contrary to the other groups. The motor reflex regulation was recovered 7 days post-MCAO-r. This result reflects an acute sensorimotor adaptation at the spinal level after MCAO-r.

Effects of exercise intensity on spatial memory performance and hippocampal synaptic plasticity in transient brain ischemic rats

Memory impairment is commonly noted in stroke survivors, and can lead to delay of functional recovery. Exercise has been proved to improve memory in adult healthy subjects. Such beneficial effects are often suggested to relate to hippocampal synaptic plasticity, which is important for memory processing. Previous evidence showed that in normal rats, low intensity exercise can improve synaptic plasticity better than high intensity exercise. However, the effects of exercise intensities on hippocampal synaptic plasticity and spatial memory after brain ischemia remain unclear. In this study, we investigated such effects in brain ischemic rats. The middle cerebral artery occlusion (MCAO) procedure was used to induce brain ischemia. After the MCAO procedure, rats were randomly assigned to sedentary (Sed), low-intensity exercise (Low-Ex), or high-intensity exercise (High-Ex) group. Treadmill training began from the second day post MCAO procedure, 30 min/day for 14 consecutive days for the exercise groups. The Low-Ex group was trained at the speed of 8 m/min, while the High-Ex group at the speed of 20 m/min. The spatial memory, hippocampal brain-derived neurotrophic factor (BDNF), synapsin-I, postsynaptic density protein 95 (PSD-95), and dendritic structures were examined to document the effects. Serum corticosterone level was also quantified as stress marker. Our results showed the Low-Ex group, but not the High-Ex group, demonstrated better spatial memory performance than the Sed group. Dendritic complexity and the levels of BDNF and PSD-95 increased significantly only in the Low-Ex group as compared with the Sed group in bilateral hippocampus. Notably, increased level of corticosterone was found in the High-Ex group, implicating higher stress response. In conclusion, after brain ischemia, low intensity exercise may result in better synaptic plasticity and spatial memory performance than high intensity exercise; therefore, the intensity is suggested to be considered during exercise training.

Expected for acquisition movement exercise is more effective for functional recovery than simple exercise in a rat model of hemiplegia

Background and purpose

The use of novel rehabilitative approaches for effecting functional recovery following stroke is controversial. Effects of different but effective rehabilitative interventions in the hemiplegic patient are not clear. We studied the effects of different rehabilitative approaches on functional recovery in the rat photochecmical cerebral infarction model.

Methods

Twenty-four male Wistar rats aged 8 weeks were used. The cranial bone was exposed under deep anesthesia. Rose bengal (20 mg/kg) was injected intravenously, and the sensorimotor area of the cerebral cortex was irradiated transcranially for 20 min with a light beam of 533-nm wavelength. Animals were divided into 3 groups. In the simple-exercise group, treadmill exercise was performed for 20 min every day. In the expected for acquisition movement-training group, beam-walking exercise was done for 20 min daily. The control group was left to recover without additional intervention. Hindlimb function was evaluated with the beam-walking test.

Results

Following cerebral infarction, dysfunction of the contralateral extremities was observed. Functional recovery was observed earlier in the expected for acquisition training group than in the other groups. Although rats in the treadmill group recovered more quickly than controls, the beam-walking group had the shortest overall recovery time.

Conclusions

Exercise facilitated functional recovery in the rat hemiplegic model, and expected for acquisition exercise was more effective than simple exercise. These findings are considered to have important implications for the future development of clinical rehabilitation programs.

Early exercise protects the blood-brain barrier from ischemic brain injury via the regulation of MMP-9 and occludin in rats

Early exercise within 24 h after stroke can reduce neurological deficits after ischemic brain injury. However, the mechanisms underlying this neuroprotection remain poorly understood. Ischemic brain injury disrupts the blood-brain barrier (BBB) and then triggers a cascade of events, leading to secondary brain injury and poor long-term outcomes. This study verified the hypothesis that early exercise protected the BBB after ischemia. Adult rats were randomly assigned to sham, early exercise (EE) or non-exercise (NE) groups. The EE and NE groups were subjected to ischemia induced by middle cerebral artery occlusion (MCAO). The EE group ran on a treadmill beginning 24 h after ischemia, 30 min per day for three days. After three-days’ exercise, EB extravasation and electron microscopy were used to evaluate the integrity of the BBB. Neurological deficits, cerebral infarct volume and the expression of MMP-9, the tissue inhibitors of metalloproteinase-1 (TIMP-1), and occludin were determined. The data indicated that early exercise significantly inhibited the ischemia-induced reduction of occludin, and an increase in MMP-9 promoted TIMP-1 expression (p < 0.01), attenuated the BBB disruption (p < 0.05) and neurological deficits (p < 0.01) and diminished the infarct volume (p < 0.01). Our results suggest that the neuroprotection conferred by early exercise was likely achieved by improving the function of the BBB via the regulation of MMP-9 and occludin.

Exercise Therapy Downregulates the Overexpression of TLR4, TLR2, MyD88 and NF-κB after Cerebral Ischemia in Rats

Toll-like receptor 2 (TLR2) and Toll-like receptor 4 (TLR4) are considered to mediate the inflammatory reaction of cerebral ischemia injury, and exercise can inhibit the activity of the Toll-like receptor signaling pathway in the peripheral blood of humans. Although physical exercise has been demonstrated to be neuroprotective in both clinical and laboratory settings, the underlying mechanism remains unclear. To clarify this critical issue, this study investigated the effects of treadmill training on the recovery of neurological function and the expression of TLR2 and TLR4 and their main downstream targets, nuclear factor-kappaB (NF-κB) and myeloid differentiation factor 88 (MyD88), in the ischemic rat brain after middle cerebral artery occlusion-reperfusion (MCAo/R). Rats were divided into seven groups: sham control without MCAo/R and five, nine and 16 days post-ischemic exercise or non-exercise. The neurological function and infarct volume were measured, and reverse transcription polymerase chain reaction (RT-PCR) and Western blotting were used to detect the expression of TLR2, TLR4, NF-κB and MyD88 in ischemic brain tissue. The results indicated that treadmill training promoted functional recovery and reduced the overexpression of TLR2, TLR4, NF-κB and MyD88 in rat brain tissue after ischemia, a finding that may have implications for understanding the mechanism of exercise therapy after brain ischemia and indicating new therapeutic strategies for the pharmacological modulation of TLR signaling.