Exercise in the Early Stage after Stroke Enhances Hippocampal Brain-Derived Neurotrophic Factor Expression and Memory Function Recovery

Exploring the pathogenesis and treatment of PSD from the perspective of gut microbiota

Post-stroke depression (PSD) is a psychological disease that can occur following a stroke and is associated with serious consequences. Research on the pathogenesis and treatment of PSD is still in the infancy stage. Patients with PSD often exhibit gastrointestinal symptoms; therefore the role of gut microbiota in the pathophysiology and potential treatment effects of PSD has become a hot topic of research. In this review, describe the research on the pathogenesis and therapy of PSD. We also describe how the gut microbiota influences neurotransmitters, the endocrine system, energy metabolism, and the immune system. It was proposed that the gut microbiota is involved in the pathogenesis and treatment of PSD through the regulation of neurotransmitter levels, vagal signaling, hypothalamic-pituitary-adrenal axis activation and inhibition, hormone secretion and release, in addition to immunity and inflammation.

Brain-Derived Neurotrophic Factor in Pediatric Acquired Brain Injury and Recovery

We review emerging preclinical and clinical evidence regarding brain-derived neurotrophic factor (BDNF) protein, genotype, and DNA methylation (DNAm) as biomarkers of outcomes in three important etiologies of pediatric acquired brain injury (ABI), traumatic brain injury, global cerebral ischemia, and stroke. We also summarize evidence suggesting that BDNF is (1) involved in the biological embedding of the psychosocial environment, (2) responsive to rehabilitative therapies, and (3) potentially modifiable. BDNF's unique potential as a biomarker of neuroplasticity and neural repair that is reflective of and responsive to both pre- and post-injury environmental influences separates it from traditional protein biomarkers of structural brain injury with exciting potential to advance pediatric ABI management by increasing the accuracy of prognostic tools and informing clinical decision making through the monitoring of therapeutic effects.

Neuroanatomical Localization of the Vestibular Cortex: A Case Report

Vertigo, a symptom of illusory movement, is caused by asymmetry of the vestibular system. The vestibular system consists of the vestibular labyrinth, cranial nerve VIII, brainstem vestibular nuclei, cerebellum, ocular motor nuclei, spinal cord, and less well-defined cerebral projections. In this day and age of artificial intelligence, machine learning, advanced imaging, and cutting-edge research in the field of neurology, the exact cortical control of vestibular function is still uncharted. A 45-year-old woman with a past medical history of labyrinthitis about 4.5 years ago (resolved) presented to hospital due to severe dizziness, emesis, and mild vertical diplopia for the past few days. Her symptom of dizziness i.e. room spinning was continuous without any postural component. MRI of the brain revealed a small stroke in the left hippocampal area, more specifically alveus of hippocampus. The patient was started on dual antiplatelet therapy and atorvastatin for secondary stroke prevention. Follow-up visit as an outpatient at one-month post hospital discharge was unremarkable without any recurrence of vertigo symptoms. We believe this may indicate that the limbic lobe has a much larger role in vestibular functioning than previously thought, and may control more vestibular operations than any other central nervous system area.

Transcutaneous Electrical Nerve Stimulation (TENS) Alleviates Brain Ischemic Injury by Regulating Neuronal Oxidative Stress, Pyroptosis, and Mitophagy

Background

As a noninvasive treatment, transcutaneous electrical nerve stimulation (TENS) has been utilized to treat various diseases in clinic. However, whether TENS can be an effective intervention in the acute stage of ischemic stroke still remains unclear. In the present study, we aimed to explore whether TENS could alleviate brain infarct volume, reduce oxidative stress and neuronal pyroptosis, and activate mitophagy following ischemic stroke.

Methods

TENS was performed at 24 h after middle cerebral artery occlusion/reperfusion (MCAO/R) in rats for 3 consecutive days. Neurological scores, the volume of infarction, and the activity of SOD, MDA, GSH, and GSH-px were measured. Moreover, western blot was performed to detect the related protein expression, including Bcl-2, Bax, TXNIP, GSDMD, caspase-1, NLRP3, BRCC3, HIF-1α, BNIP3, LC3, and P62. Real-time PCR was performed to detect NLRP3 expression. Immunofluorescence was performed to detect the levels of LC3.

Results

There was no significant difference of neurological deficit scores between the MCAO group and the TENS group at 2 h after MCAO/R operation (P > 0.05), while the neurological deficit scores of TENS group significantly decreased in comparison with MCAO group at 72 h following MACO/R injury (P < 0.05). Similarly, TENS treatment significantly reduced the brain infarct volume compared with the MCAO group (P < 0.05). Moreover, TENS decreased the expression of Bax, TXNIP, GSDMD, caspase-1, BRCC3, NLRP3, and P62 and the activity of MDA as well as increasing the level of Bcl-2, HIF-1α, BNIP3, and LC3 and the activity of SOD, GSH, and GSH-px (P < 0.05).

Conclusions

In conclusion, our results indicated that TENS alleviated brain damage following ischemic stroke via inhibiting neuronal oxidative stress and pyroptosis and activating mitophagy, possibly via the regulation of TXNIP, BRCC3/NLRP3, and HIF-1α/BNIP3 pathways.

Temporal alteration of microglia to microinfarcts in rat brain induced by the vascular occlusion with fluorescent microspheres

Microglia, the resident immune cells in the central nervous system, can monitor the microenvironment and actively respond to ischemic stroke and other brain injuries. In this procedure, microglia and neurons can cross-talk via transmembrane chemokine, Fractalkine (CX3CL1), to impact one another. We used a rat model of multifocal microinfarcts induced by the injection of fluorescent microspheres into the right common carotid artery and examined the morphological alteration of blood vessels, microglia, astrocytes, and neurons at 6 h, 1, 7, and 14 days after modeling, along with neurobehavioral tests and the staining of CX3CL1 in this study. Our results demonstrated that in the infarcted regions, astrocytes and microglia activated in response to neuronal degeneration and upregulation of cleaved caspase-3, which occurred concurrently with vascular alteration and higher expression of CX3CL1. We provided sequential histological data to shed light on the morphological changes after modeling, which would help in the identification of new targets and the choice of the ideal time window for therapeutic intervention in ischemic stroke.

Activation of BDNF- and VEGF-mediated Neuroprotection by Treadmill Exercise Training in Experimental Stroke

Early treatment of ischemic stroke is one of the most effective ways to reduce brains' cell death and promote functional recovery. This study was designed to examine the effect of aerobic exercise on post ischemia/reperfusion injury on concentration and expression of brain-derived neurotrophic factor (BDNF) and vascular endothelial growth factor (VEGF) after inducing a neuronal loss in CA1 region of hippocampus in Male Wistar rats. Three experimental groups including sham(S), ischemia/reperfusion-control (IRC) and ischemia/reperfusion exercise (IRE) were used for this purpose. The rats in the IRE group received a bilateral carotid artery occlusion treatment. They ran for 45 minutes on a treadmill five days per week for eight consecutive weeks. Cresyl violet (Nissl), Hematoxylin (H & E) and Eosin staining procedure were used to determine the extent of damage. A ladder rung walking task was used to assess the functional impairments and recovery after the ischemic lesion. ELISA and immunohistochemistry method were employed to measure BDNF and VEGF protein expressions. The result showed that the brain ischemia/reperfusion condition increased the cell death in hippocampal CA1 neurons and impaired motor performance on the ladder rung task whereas the aerobic exercise program significantly decreased the brain cell's death and improved motor skill performance. It was concluded that ischemic brain lesion decreased the BDNF and VEGF expression. It seems that the aerobic exercise following the ischemia/reperfusion potentially promotes neuroprotective mechanisms and neuronal repair and survival mediated partly by BDNF and other pathways.

The Effect and Mechanism of Exercise Training on Rats with Poststroke Depression Based on the Intestinal Flora

Depression of poststroke depression (PSD) is the most common neuropsychiatric complication after stroke. Patients with PSD had higher mortality, more cognitive disorder, lower quality of life, and higher suicidal tendency. The pathogenesis of PSD mainly involves neurotransmitter inflammatory factors, HPA and BDNF. Enteral dysfunction and intestinal flora disorders caused by stroke can participate in the pathogenesis of PSD through various ways, such as immune, endocrine, and nervous system. In this experiment, we used exercise training as an intervention means to explore the curative effect and possible mechanism by observing the changes of behavior, inflammatory factors, and intestinal flora in rats. The results show that the mechanism of exercise training to improve the depressive behavior of rats may be related to inhibiting the expression of proinflammatory factors and increasing the number of lactic acid bacteria in the intestine.

Treadmill Exercise Attenuates Cerebral Ischemia-Reperfusion Injury by Promoting Activation of M2 Microglia via Upregulation of Interleukin-4

Background: Exercise has been proven to be an effective therapy for stroke by reducing the microglia-initiated proinflammatory response. Few studies, however, have focused on the phenotypic changes in microglia cells caused by exercise training. The present study was designed to evaluate the influence of treadmill exercise on microglia polarization and the molecular mechanisms involved. Methods: Male Sprague-Dawley rats were randomly assigned into 3 groups: sham, MCAO and exercise. The middle cerebral artery occlusion (MCAO) and exercise groups received MCAO surgery and the sham group a sham operation. The exercise group also underwent treadmill exercise after the surgery. These groups were studied after 4 and 7 days to evaluate behavioral performance using a modified neurological severity score (mNSS), and infarct conditions using 2,3,5-triphenyl tetrazolium chloride. Quantitative real-time polymerase chain reaction (qRT-PCR) and Luminex was employed to determine the expressions of markers of microglia phenotypes. Western blotting was employed to identify the phosphorylation levels of Janus kinase1 (JAK1) and signal transducer and activator of transcription 6 (STAT6). Immunofluorescence was conducted to identify microglia phenotypes. Results: Treadmill exercise was found to improve neurobehavioral outcomes, mainly motor and balance functions, reduce infarct volumes and significantly increase interleukin-4 (IL-4) expression. In addition, treadmill exercise inhibited M1 microglia and promoted M2 microglia activation as evidenced by decreased M1 and increased M2 markers. Furthermore, an obvious increase in p-JAK1 and p-STAT6 was observed in the exercise group. Conclusions: Treadmill exercise ameliorates cerebral ischemia-reperfusion injury by enhancing IL-4 expression to promote M2 microglia polarization, possibly via the JAK1-STAT6 pathway.

Extracellular Vesicles in Regeneration and Rehabilitation Recovery after Stroke

Patients that survive after a stroke event may present disabilities that can persist for a long time or permanently after it. If stroke prevention fails, the prompt and combinatorial intervention with pharmacological and rehabilitation therapy is pivotal for the optimal recovery of patients and the reduction of disabilities. In the present review, we summarize some key features of the complex events that occur in the brain during and after the stroke event, with a special focus on extracellular vesicles (EVs) and their role as both carriers of biomarkers and potential therapeutics. EVs have already demonstrated their ability to be used for diagnostic purposes for multiple brain disorders and could represent valuable tools to track the regenerative and inflammatory processes occurring in the injured brain after stroke. Last, but not least, the use of artificial or stem cell-derived EVs were proved to be effective in stimulating brain remodeling and ameliorating recovery after stroke. Still, effective biomarkers of recovery are needed to design robust trials for the validation of innovative therapeutic strategies, such as regenerative rehabilitation approaches.

Association between GFAP-positive astrocytes with clinically important parameters including neurological deficits and/or infarct volume in stroke-induced animals

The effect of GFAP-positive astrocytes, as positive or negative factors on stroke complications such as infarct volume and neurological deficits is currently under debate. This review was aimed to evaluate and compare the frequency of studies that showed a positive or negative relationship between astrocyte activation with the improvement of neurological deficits and/or the decrease of infarct volume. In addition, we reviewed two possible causes of differences in results including timepoint of stroke and stroke severity. Time of GFAP assessment was considered as time point and type of stroke induction and duration of stroke as stroke severity. According to our review in the most relevant English-language studies in the PubMed, Web of Science, and Google Scholar databases from 2005 to 2020, the majority of studies (77 vs. 28) showed a negative coincidence or correlation between GFAP-positive cells with neurological improvement as well as between GFAP-positive cells with infarct volume reduction. In most reviewed studies, GFAP expression was reported as a marker related to or coinciding with worse neurological function, or greater infarct volume. However, there were also studies that showed helpful effects of GFAP-positive cells on neurological function or stroke lesion. Although there are some elucidations that the difference in these findings is due to the time point of stroke and stroke severity, our review did not confirm these interpretations.

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

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

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

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

The protective effect and mechanism of COA-Cl in acute phase after spinal cord injury

Spinal cord injury (SCI) induces severe motor and sensory dysfunction. We previously showed the neuroprotective effects of COA-Cl, a novel synthesized adenosine analog, in a rat stroke model. In this study, we evaluated the neuroprotective effects of COA-Cl in acute phase of SCI. SCI was induced in rats at the T9 vertebra by using a drop device. Rats were divided into acute and subacute groups. A 5-day dose of 6 mg/kg COA-Cl in saline was given to the acute group immediately after SCI and the subacute group 4 days after SCI. Motor function assessed by Basso-Beattie-Bresnahan scoring and inclined plane test improved significantly in the acute group while the subacute group did not. Histological evaluation and TUNEL staining revealed that both the cavity volume and apoptosis were significantly decreased in the acute group compared with the subacute group. In addition, pERK/ERK was increased in the acute group 7 days after SCI. These results suggest that COA-Cl exerts neuroprotective effects via the ERK pathway when administered in the acute phase after SCI, resulting in the recovery of motor function. COA-Cl could be a novel therapeutic agent for the acute phase of SCI.

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.

Exercise and Dementia

Several experimental and human studies documented the preventive and therapeutic effects of exercise on various diseases as well as the normal physiological function of different systems during aging. The findings of several basic animal studies and clinical investigations identified the advantageous effects of exercise as non-pharmaceutical intervention on dementia and Alzheimer's disease (AD). The main positive effects suggested for exercise are less cognitive and behavioral impairment or decline, development of health-associated conditions (stress, sleep), reduction of dementia risk factors including chronic non-communicable disease (diabetes, cardiovascular disease), increase in neurotrophins, enhancement of brain blood flow, angiogenesis, neurogenesis, synaptogenesis and synaptic plasticity in the brain memory-related region (e.g., hippocampus), and reduction of neuroinflammation and apoptosis. However, regarding the controversial evidence in literature, designing standard clinical and experimental studies to reveal the correlation between physical activity and dementia sign and symptom including biomarker alternation, brain supramolecular and molecular changes, and neuropsychological manifestation is necessary for preparation of effective guidelines and recommendations.

PUFAs, BDNF and lipoxin A4 inhibit chemical-induced cytotoxicity of RIN5F cells in vitro and streptozotocin-induced type 2 diabetes mellitus in vivo

Objective

To study whether minimal doses of arachidonic acid (AA), eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) and lipoxin A4 (LXA4) and brain-derived neurotrophic factor (BDNF), when used in combination can protect RIN5F cells from chemical-induced cytotoxicity. As a corollary, to know whether plasma BDNF and LXA4 are altered in STZ-induced type 2 DM animals.

Materials and methods

RIN5F cells, alloxan (AL), streptozotocin (STZ), doxorubicin (DB), and benzo(a)pyrene (BP) were used in this study. Chemical-induced apoptosis and changes in antioxidants, lipid peroxides and nitric oxide (NO) and LXA4 and BDNF levels in RIN5F cells were studied. Alterations in plasma concentrations of BDNF and LXA4 in STZ-induced type 2 diabetes animals was estimated.

Results

BDNF, LXA4 and AA, EPA and DHA protected (P < 0.001 and P < 0.01 respectively) against AL/STZ/DB/BP-induced toxicity to RIN5F cells in vitro. AL/ STZ/DB/BP inhibited BDNF and LXA4 production by RIN5F cells and were restored to normal by AA, EPA and DHA. Sub-optimal doses of BDNF, LXA4, AA and EPA when used in combination protected against cytotoxic action of AL/STZ/DB/BP on RIN5F cells in vitro by restoring LXA4/BDNF levels and altered antioxidant/lipid peroxides/NO levels (P < 0.01) to normal. STZ (65 mg/kg)-induced type 2 diabetes mellitus animals showed reduced plasma BDNF and LXA4 levels (P < 0.001).

Discussion

AL/STZ/DB/BP-induced cytotoxicity to RIN5F cells in vitro can be prevented by BDNF, LXA4 and AA. AL/STZ/DB/BP are cytotoxic, possibly, by suppressing the production of LXA4 and BDNF in RIN5F cells. STZ-induced type 2 DM animals have decreased plasma levels of LXA4 and BDNF.

Conclusion

The results of the present study suggest that BDNF, LXA4, EPA, DHA, AA, GLA and BDNF protect pancreatic β cells from the cytotoxic action of various chemicals and prevent development of diabetes mellitus. LXA4 seems to be the mediator of these cytoprotective actions of BDNF and PUFAs suggesting a close interaction exists among these molecules (BDNF, PUFAs and LXA4). Hence, methods developed to deliver a combination of PUFAs (especially AA), LXA4 and BDNF may prevent development of diabetes mellitus (both type 1 and type 2).

Neurogenesis promoted by the CD200/CD200R signaling pathway following treadmill exercise enhances post-stroke functional recovery in rats

Stroke is a leading cause of long-term disability worldwide; survivors often show sensorimotor and cognitive deficits. Therapeutic exercise is the most common treatment strategy for rehabilitating patients with stroke via augmentation of neurogenesis, angiogenesis, neurotrophic factors expression, and synaptogenesis. Neurogenesis plays important roles in sensorimotor and cognitive functional recovery, and can be promoted by exercise; however, the mechanism underlying this phenomenon remains unclear. In this study, we explored the effects of treadmill exercise on sensorimotor and cognitive functional recovery, as well as the potential molecular mechanisms underlying the promotion of neurogenesis in a rat model of transient middle cerebral artery occlusion (tMCAO). We found that treadmill exercise facilitated sensorimotor and cognitive functional recovery after tMCAO, and that neural stem/progenitor cell proliferation, differentiation, and migration were enhanced in the ipsilateral subventricular and subgranular zones after tMCAO. Meanwhile, the newborn neurons induced by treadmill exercise after tMCAO had the similar function with pre-existing neurons. Treadmill exercise significantly increased CD200 and CD200 receptor (CD200R) levels in the ipsilateral hippocampus and cortex. Further study revealed that treadmill exercise-induced neurogenesis and functional recovery were clearly inhibited, while Il-β and Tnf-α expression were upregulated, following lentivirus (LV)-induced suppression of post-stroke CD200R expression. Consistent with the effect of treadmill exercise, CD200Fc (a CD200R agonist) markedly promoted neurogenesis and functional recovery after stroke. In addition, CD200Fc could further enhance the functional recovery induced by treadmill exercise after stroke. Our results demonstrate the beneficial role of treadmill exercise in promoting neurogenesis and functional recovery via activating the CD200/CD200R signaling pathway and improving the inflammatory environment after stroke. Thus, the CD200/CD200R signaling pathway is a potential therapeutic target for functional recovery after stroke.

Therapeutic exercise accompanied by neuronal modulation to enhance neurotrophic factors in the brain with central nervous system disorders

Exercise is a primary therapeutic regimen in physical therapy to rehabilitate the motor function of patients with central nervous system (CNS) disorders such as cerebrovascular accident (CVA). Furthermore, exercise positively contributes to cognitive function related to neuroplasticity and neuroprotection in the hippocampus. Neurotrophins play a crucial role in neuroplasticity, neurogenesis, and neuroprotection in the CNS. Exercise enhances the expression of neurotrophins in the brain. Thus, novel regimens for kinesiotherapy in CNS disorders to further enhance exercise-induced expression are expected. In this review, we described three novel regimens for kinesiotherapy in CNS disorders based on the interaction between exercise and pharmacological treatment with the idea of "inhibition of inhibition" in the CNS.

[The efficacy of semax in the tretament of patients at different stages of ischemic stroke]

AIM

To evaluate the efficacy of semax and timing of rehabilitation on the dynamics of plasma BDNF levels, motor performance, and Barthel index score in patients after ischemic stroke (IS).

MATERIAL AND METHODS

One hundred and ten patients after IS (43 men, 67 women, mean age 58.0±9.7, Ме 63 years) were examined. All patients were divided into early (89±9 days) and late (214±22 days) rehabilitation groups. Each group was subdivided into semax+ and semax- subgroups. Standard regimen of semax included 2 courses (6000 mcg/day) for 10 days with 20 day interval. Plasma BDNF levels, motor performance on the British Medical Research Council scale and Barthel index were assessed in all groups.

RESULTS

Administration of semax, regardless of the timing of rehabilitation, increased BDNF plasma levels which remained high during the whole study period. In semax- subgroups high BDNF plasma levels were positively correlated with early rehabilitation. Administration of semax and high BDNF levels accelerated the improvement and ameliorated the final outcome of Barthel score index. There was a positive correlation between BDNF plasma levels and Barthel score, as well as a correlation between early rehabilitation and motor performance improvement. The correlation between BDNF plasma levels and Barthel score was modified by the timing of rehabilitation.

CONCLUSION

Early rehabilitation and administration of semax increase BDNF plasma level, speed functional recovery, and improve motor performance.

Neuroprotective effects of exercise in rodent models of memory deficit and Alzheimer's

Alzheimer's disease (AD) is a fastest growing neurodegenerative condition with no standard treatment. There are growing evidence about the beneficial effects of exercise in brain health promotion and slowing the cognitive decline. The aim of this study was to review the protective mechanisms of treadmill exercise in different models of rodent memory deficits. Online literature database, including PubMed-Medline, Scopus, Google scholar were searched from 2003 till 2017. Original article with English language were chosen according to following key words in the title: (exercise OR physical activity) AND (memory OR learning). Ninety studies were finally included in the qualitative synthesis. The results of these studies showed the protective effects of exercise on AD induced neurodegerative and neuroinflammatory process. Neuroperotective effects of exercise on the hippocampus seem to be increasing in immediate-early gene c-Fos expression in dentate gyrus; enhancing the Wnt3 expression and inhibiting glycogen synthase kinase-3β expression; increasing the 5-bro-mo-2'-deoxyridine-positive and doublecortin-positive cells (dentate gyrus); increasing the level of astrocytes glial fibrillary acidic protein and decrease in S100B protein, increasing in blood brain barrier integrity; prevention of oxidative stress injury, inducing morphological changes in astrocytes in the stratum radiatum of cornu ammonis 1(CA1) area; increase in cell proliferation and suppress apoptosis in dentate gyrus; increase in brain-derived neurotrophic factor and tropomyosin receptor kinase B expressions; enhancing the glycogen levels and normalizing the monocarboxylate transporter 2 expression.

Effects of swimming exercise on the extinction of fear memory in rats

We investigated the relation between swimming exercise and fear memory extinction. Rats that performed regular swimming exercise over 6 wk underwent fear conditioning. Twenty-eight days later, they were submitted to extinction tests. Swimming rats had enhanced extinction process throughout the 5 days of the extinction test compared with sedentary rats. This suggests that the swimming exercise accelerated the process of aversive memory extinction, reducing the expression of conditioned fear behavior. These results encourage further studies addressing the anxiolytic effects of exercise, with potential implications for anxiety disorders such as posttraumatic stress disorder. NEW & NOTEWORTHY We have shown that rats that performed regular swimming exercise over 6 wk had enhanced extinction process compared with sedentary animals. The swimming exercise may accelerate the process of aversive memory extinction, reducing the expression of conditioned fear behavior.

Post-stroke BDNF Concentration Changes Following Physical Exercise: A Systematic Review

Background: Research over the last two decades has highlighted the critical role of Brain-derived neurotrophic factor (BDNF) in brain neuroplasticity. Studies suggest that physical exercise may have a positive impact on the release of BDNF and therefore, brain plasticity. These results in animal and human studies have potential implications for the recovery from damage to the brain and for interventions that aim to facilitate neuroplasticity and, therefore, the rehabilitation process. Purpose: The aim of this study was to carry out a systematic review of the literature investigating how aerobic exercises and functional task training influence BDNF concentrations post-stroke in humans and animal models. Data Sources: Searches were conducted in PubMed (via National Library of Medicine), SCOPUS (Elsevier), CINAHL with Full Text (EBSCO), MEDLINE 1946-present with daily updates (Ovid) and Cochrane. Study Selection: All of the database searches were limited to the period from January, 2004 to May, 2017. Data Extraction: Two reviewers extracted study details and data. The methodological quality of the studies that used animal models was assessed using the ARRIVE Guidelines, and the study that evaluated human BDNF was assessed using the PEDro Scale. Data Synthesis: Twenty-one articles were included in this review. BDNF measurements were performed systemically (serum/plasma) or locally (central nervous system). Only one study evaluated human BDNF concentrations following physical exercise, while 20 studies were experimental studies using a stroke model in animals. A wide variation was observed in the training protocol between studies, although treadmill walking was the most common type of intervention among the studies. Studies were of variable quality: the studies that used animal models scored from 8/20 to 15/20 according to the ARRIVE Guidelines. The only study that evaluated human subjects scored 5/10 according to the PEDro scale and, which indicates a quality classified as "fair". Conclusions: The results of the current systematic review suggest that aerobic exercise promotes changes in central BDNF concentrations post-stroke. On the other hand, BDNF responses following functional exercises, such as reaching training and Constraint Induced Movement Therapy (CIMT), seem to be still controversial. Given the lack of studies evaluating post-stroke BDNF concentration following physical exercise in humans, these conclusions are based on animal work.

Veterinary Neurologic Rehabilitation: The Rationale for a Comprehensive Approach

The increase in client willingness to pursue surgical procedures, the heightened perceived value of veterinary patients, and the desire to provide comprehensive medical care have driven the recent demand of using an integrative treatment approach in veterinary rehabilitation. Physical therapy following neurologic injury has been the standard of care in human medicine for decades, whereas similar rehabilitation techniques have only recently been adapted and utilized in veterinary medicine. Spinal cord injury is the most common neurologic disease currently addressed by veterinary rehabilitation specialists and will be the primary focus of this review; however, research in other neurologic conditions will also be discussed. Of particular interest, to clients and veterinarians are techniques and modalities used to promote functional recovery after neurologic injury, which can mean the difference between life and death for many veterinary patients. The trend in human neurologic rehabilitation, often regardless of etiology, is a multimodal approach to therapy. Evidence supports faster and improved recoveries in people after neurologic injury using a combination of rehabilitation techniques. Although the primary neurological disorders researched tend to be spinal cord injury, peripheral neuropathies, allodynia, multiple sclerosis, and strokes-many correlations can be made to common veterinary neurological disorders. Such comprehensive protocols entail gait training activities in combination with neuromuscular electrical stimulation and directed exercises. Additionally, pain-relieving and functional benefits are bolstered when acupuncture is used in addition to rehabilitation. Studies, both laboratory and clinical, support the use of acupuncture in the management of neurologic conditions in small animals, specifically in cases of intervertebral disc disease, other myelopathies, and neuropathic pain conditions. Acupuncture's ability to promote analgesia, stimulate trophic factors, and decrease inflammation, including neuroinflammation, make it an alluring adjunct therapy after neurologic injury. Although there is limited research in veterinary medicine on physical techniques that expedite recovery after neurologic injury, there are sparse publications on clinical veterinary research suggesting the benefits of acupuncture, rehabilitation, and LASER in dogs with intervertebral disk disease. Accordingly, due to the relative lack of evidence-based studies in veterinary neurologic rehabilitation, much of the data available is human or laboratory-animal based, however, evidence supports the utilization of an early, comprehensive treatment protocol for optimal neurologic recovery. The rationale for why an integrative approach is critical will be detailed in this review; in addition, literature on specific physical rehabilitation techniques that have evidence of improved recoveries after neurologic injury, will be addressed.

Constraint-induced movement therapy improves efficacy of task-specific training after severe cortical stroke depending on the ipsilesional corticospinal projections

Descending spinal pathways (corticospinal, rubrospinal, and reticulospinal) are believed to contribute to functional recovery resulting from rehabilitative training after stroke. However, the contribution of each pathway remains unclear. In the current study, we investigated rehabilitation-induced functional recovery and remodelling of the descending spinal pathways after severe cortical stroke in rats followed by 3 weeks of various rehabilitation [constraint-induced movement therapy (CIMT), skilled forelimb reaching, rotarod, and treadmill exercise]. Following photothrombotic stroke, 96% of corticospinal neurons in the ipsilesional motor cortex were destroyed. Despite the preservation of 82% of total spinal projection neurons (e.g. rubrospinal and reticulospinal projection neurons), rats showed persistent and severe disability, especially in skilled motor function. In this severe stroke model, only CIMT promoted functional recovery, associated with increased corticospinal projections from the peri-infarct motor cortex. Rehabilitation-induced recovery was reversed when the restored corticospinal neurons were destroyed by a second stroke. These data indicate that training-induced functional recovery is dependent on ipsilesional corticospinal projections, which highlights the importance of using strategies to enhance survival, axonal remodelling, or regeneration of corticospinal neurons to effectively restore function in severely affected stroke patients.

On the Run for Hippocampal Plasticity

Accumulating research in rodents and humans indicates that exercise benefits brain function and may prevent or delay onset of neurodegenerative conditions. In particular, exercise modifies the structure and function of the hippocampus, a brain area important for learning and memory. This review addresses the central and peripheral mechanisms underlying the beneficial effects of exercise on the hippocampus. We focus on running-induced changes in adult hippocampal neurogenesis, neural circuitry, neurotrophins, synaptic plasticity, neurotransmitters, and vasculature. The role of peripheral factors in hippocampal plasticity is also highlighted. We discuss recent evidence that systemic factors released from peripheral organs such as muscle (myokines), liver (hepatokines), and adipose tissue (adipokines) during exercise contribute to hippocampal neurotrophin and neurogenesis levels, and memory function. A comprehensive understanding of the body-brain axis is needed to elucidate how exercise improves hippocampal plasticity and cognition.

Association Between Cerebral Hypoperfusion and Cognitive Impairment in Patients With Chronic Vertebra-Basilar Stenosis

Objective: This study aimed to investigate the association between cognitive impairment and cerebral haemodynamic changes in patients with chronic vertebra-basilar (VB) stenosis. Methods: Patients with severe posterior circulation VB stenosis and infarction or a history of infarction for more than 2 weeks from January 2014 to January 2015 were enrolled (n = 96). They were divided into three groups, namely, the computed tomography perfusion (CTP) normal group, the CTP compensated group, and the CTP decompensated group. Cognitive function was assessed using a validated Chinese version of the Mini-Mental State Examination (MMSE), the Frontal Assessment Battery (FAB), and the Repeatable Battery for the Assessment of Neuropsychological Status (RBANS). Regression models were used to identify independent risk factors for cognitive impairment. Results: The MMSE and FAB scores of patients in the CTP decompensated group were significantly lower than those of patients in the CTP normal and CTP compensated groups (all p < 0.05). The RBANS total and its domain scores, including immediate memory, visual acuity, and delayed memory, in the CTP compensated and CTP decompensated groups were significantly lower than those in the CTP normal group (all p < 0.05). Multiple regression analyses showed that CTP compensation, CTP decompensation, severe VB tandem stenosis, and multiple infarctions were independent risk factors for cognitive impairment. Conclusions: Low perfusion caused by severe VB stenosis can lead to extensive cognitive impairments in areas such as immediate memory, visual span, and delayed memory.

Flavanol-rich cocoa consumption enhances exercise-induced executive function improvements in humans

OBJECTIVE

Aerobic exercise is known to acutely improve cognitive functions, such as executive function (EF) and memory function (MF). Additionally, consumption of flavanol-rich cocoa has been reported to acutely improve cognitive function. The aim of this study was to determine whether high cocoa flavanol (CF; HCF) consumption would enhance exercise-induced improvement in cognitive function. To test this hypothesis, we examined the combined effects of HCF consumption and moderate-intensity exercise on EF and MF during postexercise recovery.

METHODS

Ten healthy young men received either an HCF (563 mg of CF) or energy-matched low CF (LCF; 38 mg of CF) beverage 70 min before exercise in a single-blind counterbalanced manner. The men then performed moderate-intensity cycling exercise at 60% of peak oxygen uptake for 30 min. The participants performed a color-word Stroop task and face-name matching task to evaluate EF and MF, respectively, during six time periods throughout the experimental session.

RESULTS

EF significantly improved immediately after exercise compared with before exercise in both conditions. However, EF was higher after HCF consumption than after LCF consumption during all time periods because HCF consumption improved EF before exercise. In contrast, HCF consumption and moderate-intensity exercise did not improve MF throughout the experiment.

CONCLUSION

The present findings demonstrated that HCF consumption before moderate-intensity exercise could enhance exercise-induced improvement in EF, but not in MF. Therefore, we suggest that the combination of HCF consumption and aerobic exercise may be beneficial for improving EF.

The Effect of Aerobic Exercise on Brain-Derived Neurotrophic Factor in People with Neurological Disorders: A Systematic Review and Meta-Analysis

OBJECTIVE

To determine the effect of aerobic exercise on brain-derived neurotrophic factor (BDNF) levels in people with neurological disorders.

DATA SOURCES

Six electronic databases (CINAHL, PubMed, Cochrane, PsycINFO, SportDiscus, and Web of Science) were searched until the end of December 2016.

STUDY SELECTION

Experimental or observational studies of people with neurological disorders who undertook an exercise intervention with BDNF as an outcome measure. The search strategy yielded 984 articles.

DATA EXTRACTION

Study data were independently extracted from each article. Methodological quality of studies was assessed using the Physiotherapy Evidence Database (PEDro) scale. A meta-analysis was planned based on the assessment of predetermined criteria.

DATA SYNTHESIS

Eleven articles were included. Studies employed either a program of aerobic exercise, a single bout of aerobic exercise, or both. A meta-analysis of studies comparing a program of aerobic exercise against usual care/nil therapy showed a large effect (SMD: 0.84, 95% CI 0.47-1.20, p < 0.001) in favour of aerobic exercise to increase levels of BDNF. Findings for a single bout of aerobic exercise were mixed. Quality of studies was low (PEDro average score 4.3/10).

CONCLUSIONS

A program of aerobic exercise may contribute to increased levels of BDNF in neurological populations.

Assessed and Emerging Biomarkers in Stroke and Training-Mediated Stroke Recovery: State of the Art

Since the increasing update of the biomolecular scientific literature, biomarkers in stroke have reached an outstanding and remarkable revision in the very recent years. Besides the diagnostic and prognostic role of some inflammatory markers, many further molecules and biological factors have been added to the list, including tissue derived cytokines, growth factor-like molecules, hormones, and microRNAs. The literatures on brain derived growth factor and other neuroimmune mediators, bone-skeletal muscle biomarkers, cellular and immunity biomarkers, and the role of microRNAs in stroke recovery were reviewed. To date, biomarkers represent a possible challenge in the diagnostic and prognostic evaluation of stroke onset, pathogenesis, and recovery. Many molecules are still under investigation and may become promising and encouraging biomarkers. Experimental and clinical research should increase this list and promote new discoveries in this field, to improve stroke diagnosis and treatment.

Axonal remodeling in the corticospinal tract after stroke: how does rehabilitative training modulate it?

Stroke causes long-term disability, and rehabilitative training is commonly used to improve the consecutive functional recovery. Following brain damage, surviving neurons undergo morphological alterations to reconstruct the remaining neural network. In the motor system, such neural network remodeling is observed as a motor map reorganization. Because of its significant correlation with functional recovery, motor map reorganization has been regarded as a key phenomenon for functional recovery after stroke. Although the mechanism underlying motor map reorganization remains unclear, increasing evidence has shown a critical role for axonal remodeling in the corticospinal tract. In this study, we review previous studies investigating axonal remodeling in the corticospinal tract after stroke and discuss which mechanisms may underlie the stimulatory effect of rehabilitative training. Axonal remodeling in the corticospinal tract can be classified into three types based on the location and the original targets of corticospinal neurons, and it seems that all the surviving corticospinal neurons in both ipsilesional and contralesional hemisphere can participate in axonal remodeling and motor map reorganization. Through axonal remodeling, corticospinal neurons alter their output selectivity from a single to multiple areas to compensate for the lost function. The remodeling of the corticospinal axon is influenced by the extent of tissue destruction and promoted by various therapeutic interventions, including rehabilitative training. Although the precise molecular mechanism underlying rehabilitation-promoted axonal remodeling remains elusive, previous data suggest that rehabilitative training promotes axonal remodeling by upregulating growth-promoting and downregulating growth-inhibiting signals.