Endurance exercise regimens induce differential effects on brain-derived neurotrophic factor, synapsin-I and insulin-like growth factor I after focal ischemia

Skilled reaching training combined with pharmacological inhibition of histone deacetylases potentiated motor recovery after intracerebral hemorrhage in a synergic manner

Neuronal recovery after stroke is supported by the expression of genes involved in neuronal plasticity and neuroprotection. As an epigenetic modification, histone acetylation modulates gene expression elicited by neurorehabilitation. This study aimed to investigate the combined effects of skilled reaching training (SRT) and the pharmacological inhibition of histone deacetylase (HDAC) using sodium butyrate (NaB) on motor function recovery after intracerebral hemorrhage (ICH). Wistar rats were divided into five groups: Sham, ICH, ICH plus SRT (ICH + SRT), ICH plus NaB administration (ICH + NaB), and ICH plus SRT plus NaB administration (ICH + SRT + NaB). ICH surgery was conducted based on the microinjection of collagenase into the striatum near the internal capsule. NaB treatment (300 mg/kg injected intraperitoneally) and SRT were performed five days a week for four weeks after ICH surgery, followed by tissue collection. After the intervention, the ICH + SRT + NaB group exhibited significant improvement in skilled motor function, accompanied by a significant increase in neurotrophin 4 and synaptophysin expression in the ipsilateral motor cortex. This study showed that combination therapy of SRT and HDAC inhibition synergistically promoted motor recovery after ICH, accompanied by the upregulation of crucial genes for neuroplasticity. Taken together, this study indicates that HDAC inhibition could represent an enriched neuronal platform for neurorehabilitation after ICH.

The Effects of Treadmill Exercise on the Recovery of Synaptic Plasticity in Septic Mice: A Focus on Brain-Derived Neurotrophic Factor/Tropomyosin-Related Kinase B Signaling

BACKGROUND

Sepsis-associated encephalopathy causes irreversible cognitive dysfunction, yet no effective pharmacological treatments are available. The hippocampus is particularly vulnerable to sepsis-induced damage, and impairments in hippocampal synaptic plasticity, particularly late-phase long-term potentiation (L-LTP), are implicated in cognitive dysfunction. Brain-derived neurotrophic factor (BDNF) and its receptor, tropomyosin receptor kinase B (TrkB), play crucial roles in maintaining L-LTP. While exercise enhances cognitive function, its effects on hippocampal synaptic plasticity under conditions mimicking early rehabilitation after sepsis remain unclear. This study evaluated the impact of treadmill exercise on hippocampal L-LTP in a murine sepsis model, using a protocol resembling early clinical rehabilitation.

METHODS

A total of 267 C57BL/6J mice (8-12 weeks old) underwent cecal ligation and puncture (CLP) or sham surgery, with or without treadmill exercise (30 min/d for 7 days postsurgery). Mice were divided into 4 groups: (1) sham + sedentary, (2) sham + exercise, (3) CLP + sedentary, and (4) CLP + exercise. The primary outcome was hippocampal L-LTP, assessed via electrophysiology. Secondary outcomes included hippocampal BDNF levels, locomotor activity, and survival curves. Additionally, the role of BDNF/TrkB signaling was examined using ANA-12, an antagonist of the BDNF receptor TrkB. Data are presented as mean ± standard deviation.

RESULTS

L-LTP at the Schaffer collateral-CA1 synapse was significantly impaired in CLP mice 1 week after surgery (CLP + sedentary: 144% ± 15% vs sham + sedentary: 185% ± 34%; P = .008). Exercise restored L-LTP in CLP mice (CLP + exercise: 189% ± 36% vs CLP + sedentary: 144% ± 15%, P = .003), but this effect was abolished by ANA-12 (CLP + exercise + ANA-12: 155% ± 22% vs CLP + exercise + vehicle: 194% ± 37%, P < .001). Exercise also restored hippocampal BDNF levels reduced by CLP (CLP + exercise: 4190 ± 671 pg/mg protein versus CLP + sedentary: 3220 ± 647 pg/mg protein, P = .007). Locomotor activity was impaired in CLP mice but not significantly improved by exercise (P = .38). Furthermore, the survival curves differed significantly between CLP mice with and without treadmill exercise, as determined by post hoc analysis after a log-rank test (P = .003).

CONCLUSIONS

Treadmill exercise therapy restored hippocampal L-LTP impaired by sepsis, at least partially mediated by activation of the BDNF/TrkB signaling pathway. Additionally, exercise altered the survival curve, though it had limited effects on locomotor activity. These findings suggest that exercise therapy may mitigate sepsis-induced synaptic dysfunction.

High frequency exercise after human cranial bone-derived mesenchymal stem cells transplantation enhances motor functional recovery following traumatic brain injury in mice

Traumatic brain injury (TBI) causes a neurological impairment of the central nervous system that may induce severe motor deficits. In this study, human cranial bone-derived mesenchymal stem cells (hcMSCs) were transplanted into a mouse TBI model, and the effects of differences in exercise frequency were examined as a rehabilitation approach to improve motor function after cell transplantation. Twenty-four hours after TBI induction, phosphate-buffered saline or hcMSCs were intravenously injected into mice that were divided into a non-exercise group, a low-frequency exercise group (LF Ex), and a high-frequency exercise group (HF Ex). Beam walking tests and rotarod tests were performed over time to assess motor function. Injured brain tissues were collected for mRNA and protein expression analysis on days 8 and 35 after TBI induction. On days 28 and 35 after TBI induction, significant associations were found between hcMSC transplantation (T) and exercise factors. Notably, the T + HF Ex group exhibited a significant improvement in motor function compared with the other groups. Moreover, we found that the mRNA and protein expression levels of growth associated protein 43 (GAP-43), hepatocyte growth factor (HGF), and nerve growth factor (NGF) were significantly higher in the T + HF Ex group than in other groups. Increased expression of GAP-43 enhances synaptic regeneration and promotes functional recovery. High expression of NGF accelerates neural differentiation, and HGF ensures the efficacy of hcMSCs. These data suggest that hcMSC transplantation combined with high-frequency exercise is a promising option for TBI treatment.

Enhancing Neuroplasticity for Post-Stroke Motor Recovery: Mechanisms, Models, and Neurotechnology

Stroke remains a significant global health challenge, imposing substantial socioeconomic burdens. Post-stroke neurorehabilitation aims to maximize functional recovery and mitigate persistent disability through effective neuromodulation, while many patients experience prolonged recovery periods with suboptimal outcomes. This review explores innovative neurotechnologies and therapeutic strategies enhancing neuroplasticity for post-stroke motor recovery, with a particular focus on the subacute and chronic phases. We examine key neuroplasticity mechanisms and rehabilitation models informing neurotechnology use, including the vicariation model, the interhemispheric competition model, and the bimodal balance-recovery model. Building on these theoretical foundations, current neurotechnologies are categorized into endogenous drivers of neuroplasticity (e.g., task-oriented training, brain-computer interfaces) and exogenous drivers (e.g., brain stimulation, muscular electrical stimulation, robot-assisted passive movement). However, most approaches lack tailored adjustments combining volitional behavior with brain neuromodulation. Given the heterogeneous effects of current neurotechnologies, we propose that future directions should focus on personalized rehabilitation strategies and closed-loop neuromodulation. These advanced approaches may provide deeper insights into neuroplasticity and potentially expand recovery possibilities for stroke patients.

Effects of voluntary or involuntary exercise in adolescent male rats exposed to chronic social isolation on cognition, behavior, and neurotrophic factors

This study investigated the effects of voluntary and involuntary/regular exercise on neurotrophic factors in the brain, cognitive functions, and anxiety in socially isolated adolescent male rats. In this study, 42 adolescent male Sprague-Dawley rats were divided into six groups: control (C), socially isolated (SI), voluntary exercise (VE), regular exercise (RE), socially isolated + voluntary exercise (SI-VE), and socially isolated + regular exercise (SI-RE). Socially isolated groups were kept in separate cages for 4 weeks. Treadmill and wheel running were used in the exercise groups. The following behavioral tests-elevated plus maze (EPM), open field, ultrasonic vocalization (USV), and Morris water maze (MWM)-rats were euthanized, and brain-derived neurotrophic factor (BDNF), nerve growth factor (NGF), and vascular endothelial growth factor (VEGF) levels were measured in the prefrontal cortex (PFC) and hippocampus. Statistically, the differences between the groups were evaluated by one-way ANOVA and post hoc LSD tests using IBM SPSS software. In the EPM, locomotor activity was higher in the voluntary exercise groups. In the MWM, both regular exercise groups found the platform faster. In the USV, the SI-RE group produced more 50-kHz sounds. BDNF and NGF levels in the hippocampus were higher in the SI-RE and SI-VE groups; VEGF levels were higher in the SI-RE group. Neuron density in the PFC increased in the SI-RE and VE groups, while neuron density in the hippocampus increased in the SI-RE, SI-VE, and VE groups. According to the findings, we showed that voluntary exercise reduces social isolation-induced anxiety, and involuntary/regular exercise both reduces anxiety and has potential benefits on cognitive functions.

Light-Sheet Fluorescence Imaging Reveals Three-Dimensional Amyloid Burden Reduction Following Five Weeks of Swimming Exercise in Alzheimer's Mouse

Emerging evidence from observational studies suggests that lifestyle modifications, particularly moderate-intensity exercise, may confer neuroprotective benefits against dementia, potentially by enhancing brain resistance through clearance mechanisms. Using light-sheet fluorescence microscopy (LSFM) with tissue clearing, we investigated the role of voluntary swimming in ameliorating β-amyloid pathology in a transgenic Alzheimer's disease (AD) mouse model. Twenty 52-week-old hAPPsw mice were randomly divided into a 5-week voluntary swimming intervention group and a control group (each n = 10). Each session included a 10-min swim followed by a 10-min rest, escalating from one session per day in the first week to three sessions per day by the fifth week. The excised brains were prepared using tissue-clearing and volume immunostaining with thioflavin-S for β-amyloid. For LSFM imaging, the individual plaque area and volume, total plaque load, and morphological parameters were quantified via an Imaris-based three-dimensional (3D) volumetric surface model. Visual comparison revealed that the intervention group presented significantly lower β-amyloid accumulation. The total surface volume of β-amyloid accumulation in the intervention group was significantly lower than that of the control group (intervention, 122,180,948 μm3 [105,854,660-169,063,081]; control, 167,201,016 μm3 [139,367,765-193,535,450]; p = 0.043). There were no significant differences in the morphological parameters, such as ellipticity and sphericity. Our LSFM study demonstrated notable reductions in β-amyloid, as evidenced by a decrease in total surface volume, in 52-week-old transgenic mice after a 5-week structured swimming program, supporting the notion that even in advanced AD stages, leisure-time voluntary swimming serves as an efficacious intervention for augmenting resistance to pathology.

Effects of exercise on brain-derived neurotrophic factor in Alzheimer's disease models: A systematic review and meta-analysis

A growing body of research examining effects of exercise on brain-derived neurotrophic factor (BDNF) in Alzheimer's disease (AD) models, while due to differences in gender, age, disease severity, brain regions examined, and type of exercise intervention, findings of available studies were conflicting. In this study, we aimed to evaluate current evidence regarding effects of exercise on BDNF in AD models. Searches were performed in PubMed, Web of Science, Cochrane, and EBSCO electronic databases, through July 20, 2023. We included studies that satisfied the following criteria: eligible studies should (1) report evidence on experimental work with AD models; (2) include an exercise group and a control group (sedentary); (3) use BDNF as the outcome indicator; and (4) be randomized controlled trials (RCTs). From 1196 search records initially identified, 36 studies met the inclusion criteria. There was a significant effect of exercise on increasing BDNF levels in AD models [standardized mean differences (SMD) = 0.98, P < 0.00001]. Subgroup analysis showed that treadmill exercise (SMD = 0.92, P< 0.0001), swimming (SMD = 1.79, P< 0.0001), and voluntary wheel running (SMD = 0.51, P= 0.04) were all effective in increasing BDNF levels in AD models. In addition, exercise significantly increased BDNF levels in the hippocampus (SMD = 0.92, P< 0.00001) and cortex (SMD = 1.56, P= 0.02) of AD models. Exercise, especially treadmill exercise, swimming, and voluntary wheel running, significantly increased BDNF levels in hippocampus and cortex of AD models, with swimming being the most effective intervention type.

Physical exercise regulates microglia in health and disease

There is a well-established link between physical activity and brain health. As such, the effectiveness of physical exercise as a therapeutic strategy has been explored in a variety of neurological contexts. To determine the extent to which physical exercise could be most beneficial under different circumstances, studies are needed to uncover the underlying mechanisms behind the benefits of physical activity. Interest has grown in understanding how physical activity can regulate microglia, the resident immune cells of the central nervous system. Microglia are key mediators of neuroinflammatory processes and play a role in maintaining brain homeostasis in healthy and pathological settings. Here, we explore the evidence suggesting that physical activity has the potential to regulate microglia activity in various animal models. We emphasize key areas where future research could contribute to uncovering the therapeutic benefits of engaging in physical exercise.

Potential effect of physical exercise on the downregulation of BDNF mRNA expression in rat hippocampus following intracerebral hemorrhage

OBJECTIVES

Physical exercise is known to induce expression of the neuroprotective brain derived neurotrophic factor (BDNF) in the hippocampus. This study examined the effects of physical exercise on hippocampal BDNF expression and the potential benefits for preventing remote secondary hippocampal damage and neurological impairment following intracerebral hemorrhage (ICH).

MATERIALS AND METHODS

Wistar rats were randomly assigned to sham-operated, ICH, and ICH followed by exercise (ICH/Ex) groups. The two ICH groups were injected with type IV collagenase into the left basal ganglia, while sham animals were injected with equal-volume saline. The ICH/Ex group rats ran on a treadmill at 11 m/min for 30 min/day from day 3 to 16 post-ICH. All animals were examined for neurological function on day 2 pretreatment and from day 3 to 15 posttreatment, for spontaneous motor activity in the open field on day 15, and for cognitive ability using the object location test on day 16. Animals were then euthanized and bilateral hippocampi collected for gene expression analyses.

RESULTS

Experimental ICH induced neurological deficits that were not reversed by exercise. In contrast, ICH did not alter spontaneous activity or object location ability. Expression of BDNF mRNA of the ICH group was significantly downregulated in the ipsilateral hippocampus compared to the SHAM group, but this downregulation was not shown in the ICH/Ex group. The ICH/Ex group showed the downregulation of caspase-3 mRNA expression in the contralateral hippocampus compared to the SHAM group, while neither ICH nor exercise influenced toll-like receptor 4 mRNA expression.

CONCLUSIONS

ICH induced the secondary BDNF downregulation in the hippocampus remote from the lesion, whereas physical exercise might partially mitigate the downregulation.

Impact of physical activity on brain oxidative metabolism and intrinsic capacities in young swiss mice fed a high fat diet

Type 2 diabetes and obesity characterized by hallmarks of insulin resistance along with an imbalance in brain oxidative metabolism would impair intrinsic capacities (ICs), a new concept for assessing mental and physical functioning. Here, we explored the impact of physical activity on antioxidant responses and oxidative metabolism in discrete brain areas of HFD or standard diet (STD) fed mice but also its consequences on specific domains of ICs. 6-week-old Swiss male mice were exposed to a STD or a HFD for 16 weeks and half of the mice in each group had access to an activity wheel and the other half did not. As expected HFD mice displayed peripheral insulin resistance but also a persistent inhibition of aconitase activity in cortices revealing an increase in mitochondrial reactive oxygen species (ROS) production. Animals with access to the running wheel displayed an improvement of insulin sensitivity regardless of the diet factor whereas ROS production remained impaired. Moreover, although the access of the running wheel did not influence mitochondrial biomass, in the oxidative metabolism area, it produced a slight decrease in brain SOD1 and catalase expression notably in HFD fed mice. At the behavioural level, physical exercise produced anxiolytic/antidepressant-like responses and improved motor coordination in both STD and HFD fed mice. However, this non-pharmacological intervention failed to enhance cognitive performance. These findings paint a contrasting landscape about physical exercise as a non-pharmacological intervention for positively orienting the aging trajectory.

The Post-conditioning Acute Strength Exercise Facilitates Contextual Fear Memory Consolidation Via Hippocampal N-methyl-D-aspartate-receptors

The benefits of aerobic exercises for memory are known, but studies of strength training on memory consolidation are still scarce. Exercise stimulates the release of metabolites and myokines that reaching the brain stimulate the activation of NMDA-receptors and associated pathways related to cognition and synaptic plasticity. The aim of the present study was to investigate whether the acute strength exercise could promote the consolidation of a weak memory. We also investigated whether the effects of strength exercise on memory consolidation and on the BDNF and synapsin I levels depends on the activation of NMDA-receptors. Male Wistar rats were submitted to strength exercise session after a weak training in contextual fear conditioning paradigm to investigate the induction of memory consolidation. To investigate the participation of NMDA-receptors animals were submitted to contextual fear training and strength exercise and infused with MK801 or saline immediately after exercise. To investigate the participation of NMDA-receptors in BDNF and synapsin I levels the animals were submitted to acute strength exercise and infused with MK801 or saline immediately after exercise (in absence of behavior experiment). Results showed that exercise induced the consolidation of a weak memory and this effect was dependent on the activation of NMDA-receptors. The hippocampal overexpression of BDNF and Synapsin I through exercise where NMDA-receptors dependent. Our findings showed that strength exercise strengthened fear memory consolidation and modulates the overexpression of BDNF and synapsin I through the activation of NMDA-receptors dependent signaling pathways.

The different cell-specific mechanisms of voluntary exercise and forced exercise in the nucleus accumbens

Physical inactivity is a global epidemic. People who take the initiative to exercise will feel pleasure during the exercise process and stick with it for a long time, while people who passively ask for exercise will feel pain and cannot stick with it. However, the neural mechanisms underlying voluntary and forced exercise remain unclear. Here, we report that voluntary running increased the frequency and amplitude of miniature excitatory postsynaptic currents (mEPSC) but decreased membrane excitability in D1R-MSNs, whereas D2R-MSNs did not change in mEPSC and membrane excitability. Forced running increased the frequency of mEPSC and membrane excitability in D2R-MSNs, but D1R-MSNs did not change, which may be the mechanism by which forced exercise has a non-rewarding effect. These findings provide new insights into how voluntary and forced exercise mediate reward and non-reward effects.

Epigenetic modifications in the motor cortex caused by exercise or pharmacological inhibition of histone deacetylases (HDACs) after intracerebral hemorrhage (ICH)

Epigenetic regulation is expected to provide an enriched platform for neurorehabilitation of post-stroke patients. Acetylation of specific lysine residues in histones is a potent epigenetic target essential for transcriptional regulation. Exercise modulates histone acetylation and gene expression in neuroplasticity in the brain. This study sought to examine the effect of epigenetic treatment using a histone deacetylase (HDAC) inhibitor, sodium butyrate (NaB), and exercise on epigenetic markers in the bilateral motor cortex after intracerebral hemorrhage (ICH) to identify a more enriched neuronal condition for neurorehabilitation. Forty-one male Wistar rats were randomly divided into five groups: sham (n = 8), control (n = 9), NaB, exercise (n = 8), and NaB and exercise (n = 8). Intraperitoneal administration of an HDAC inhibitor (300 mg/kg NaB) and treadmill exercise (11 m/min for 30 min) was conducted five days a week for approximately-four weeks. ICH specifically decreased the acetylation level of histone H4 in the ipsilateral cortex, and HDAC inhibition with NaB increased the acetylation level of histone H4 over the sham level, accompanied by an improvement in motor function as assessed by the cylinder test. Exercise increased the acetylation levels of histones (H3 and H4) in the bilateral cortex. Synergistic effects of exercise and NaB were not observed during histone acetylation. Pharmacological treatment with a HDAC inhibitor and exercise can provide an enriched epigenetic platform for neurorehabilitation in an individual manner.

High-intensity training with short and long intervals regulate cortical neurotrophic factors, apoptosis markers and chloride homeostasis in rats with stroke

BACKGROUND/PURPOSE

The optimal endurance exercise parameters remain to be defined to potentiate long-term functional recovery after stroke. We aim to assess the effects of individualized high-intensity interval training (HIIT) with either long or short intervals on neurotrophic factors and their receptors, apoptosis markers and the two-main cation-chloride cotransporters in the ipsi- and contralesional cerebral cortices in rats with cerebral ischemia. Endurance performance and sensorimotor functions were also assessed METHODS: : Rats with a 2-hour transient middle cerebral artery occlusion (tMCAO) performed work-matched HIIT4 (intervals: 4min) or HIIT1 (intervals: 1min) on treadmill for 2 weeks. Incremental exercises and sensorimotor tests were performed at day 1 (D1), D8, and D15 after tMCAO. Molecular analyses were achieved in both the paretic and non-paretic triceps brachii muscles and the ipsi- and contralesional cortices at D17 RESULTS: : Gains in endurance performance are in a time-dependent manner from the first week of training. This enhancement is supported by the upregulation of metabolic markers in both triceps brachii muscles. Both regimens alter the expression of neurotrophic markers and chloride homeostasis in a specific manner in the ipsi- and contralesional cortices. HIIT acts on apoptosis markers by promoting anti-apoptotic proteins in the ipsilesional cortex CONCLUSION: : HIIT regimens seem to be of clinical relevance in the critical period of stroke rehabilitation by strongly improving aerobic performance. Also, the observed cortical changes suggest an influence of HIIT on neuroplasticity in both ipsi- and contralesional hemispheres. Such neurotrophic markers might be considered as biomarkers of functional recovery in individuals with stroke.

The Effects of Four Weeks of Chiropractic Spinal Adjustments on Blood Biomarkers in Adults with Chronic Stroke: Secondary Outcomes of a Randomized Controlled Trial

Certain blood biomarkers are associated with neural protection and neural plasticity in healthy people and individuals with prior brain injury. To date, no studies have evaluated the effects chiropractic care on serum brain-derived neurotrophic factor (BDNF), insulin-like growth factor-II (IGF-II) and glial cell-derived neurotrophic factor (GDNF) in people with stroke. This manuscript reports pre-specified, exploratory, secondary outcomes from a previously completed parallel group randomized controlled trial. We evaluated differences between four weeks of chiropractic spinal adjustments combined with the usual physical therapy (chiro + PT) and sham chiropractic with physical therapy (sham + PT) on resting serum BDNF, IGF-II and GDNF in 63 adults with chronic stroke. Blood samples were assessed at baseline, four weeks (post-intervention), and eight weeks (follow-up). Data were analyzed using a linear multivariate mixed effects model. Within both groups there was a significant decrease in the mean log-concentration of BDNF and IGF-II at each follow-up, and significant increase log-concentration of GDNF at eight-weeks' follow-up. However, no significant between-group differences in any of the blood biomarkers at each time-point were found. Further research is required to explore which factors influence changes in serum BDNF, IGF-II and GDNF following chiropractic spinal adjustments and physical therapy.

Physical inactivity amplifies the negative association between sleep quality and depressive symptoms

Poor sleep quality and physical inactivity are known risk factors for depressive symptoms. Yet, whether these factors differently contribute to depressive symptoms and whether they interact with one another remains unclear. Here, we examined how sleep quality and physical activity influence depressive symptoms in 79,274 adults 50 years of age or older (52.4% women) from the Survey of Health, Aging and Retirement in Europe (SHARE) study. Sleep quality (poor vs. good), physical activity (inactive vs. active), and depressive symptoms (0 to 12 score) were repeatedly collected (7 waves of data collection) between 2004 and 2017. Results showed that sleep quality and physical activity were associated with depressive symptoms. Specifically, participants with poorer sleep quality reported more depressive symptoms than participants with better sleep quality (b = 1.85, 95% CI = 1.83-1.86, p < .001). Likewise, compared to physically active participants, physically inactive participants reported more depressive symptoms (b = 0.44, 95% CI = 0.42-0.45, p < .001). Moreover, sleep quality and physical activity showed an interactive association with depressive symptoms (b = 0.17, 95% CI = 0.13-0.20, p < .001). The negative association between poor sleep quality and higher depressive symptoms was stronger in physically inactive than active participants. These findings suggest that, in adults 50 years of age or older, both poor sleep quality and physical inactivity are related to an increase in depressive symptoms. Moreover, the detrimental association between poor sleep quality and depressive symptoms is amplified in physically inactive individuals.

Chronic, acute and protocol-dependent effects of exercise on psycho-physiological health during long-term isolation and confinement

Exercise could prevent physical and psychological deteriorations, especially during pandemic times of lock-down scenarios and social isolation. But to meet both, the common exercise protocols require optimization based on holistic investigations and with respect to underlying processes. This study aimed to explore individual chronic and acute effects of continuous and interval running exercise on physical and cognitive performance, mood, and affect and underlying neurophysiological factors during a terrestrial simulated space mission. Six volunteers (three females) were isolated for 120 days. Accompanying exercise training consisted of a continuous and interval running protocol in a cross-over design. Incremental stage tests on a treadmill were done frequently to test physical performance. Actigraphy was used to monitor physical activity level. Cognitive performance, mood (MoodMeter®), affect (PANAS), brain-derived neurotrophic factor (BDNF), insulin-like growth factor 1 (IGF-1), vascular-endothelial growth factor (VEGF), and saliva cortisol were investigated prior to, four times during, and after isolation, pre- and post-exercise on two separate days, respectively. As a chronic effect, physical performance increased (and IGF-1 tended) in the course of isolation and training until the end of isolation. Subjective mood and affect state, as well as cognitive performance, basal BDNF and VEGF levels, were well-preserved across the intervention. No acute effects of exercise were detected, besides slower reaction time after exercise in two out of nine cognitive tests, testing sensorimotor speed and memory of complex figures. Consistently higher basal IGF-1 concentrations and faster reaction time in the psychomotor vigilance test were found for the continuous compared to the interval running protocol. The results suggest that 120 days of isolation and confinement can be undergone without cognitive and mental deteriorations. Regular, individual aerobic running training supporting physical fitness is hypothesized to play an important role in this regard. Continuous running exercise seems to trigger higher IGF-1 levels and vigilance compared to interval running. Systematic and prolonged investigations and larger sample size are required to follow up on exercise-protocol specific differences in order to optimize the exercise intervention for long-term psycho-physiological health and well-being.

Zfp580 Regulates Paracrine and Endocrine Igf1 and Igfbp3 Differently in the Brain and Blood After a Murine Stroke

Insulin-like growth factor 1 (Igf1) and insulin-like growth factor binding protein 3 (Igfbp3) are endocrine and paracrine factors that influence stroke occurrence, severity, and recovery. Low levels of endocrine Igf1 and Igfbp3 were associated with larger infarct volumes and unfavorable outcomes. Paracrine Igf1 is brain cytoprotective and improves functional recovery after stroke. In this study, we evaluated the effects of zinc finger protein 580 (Zfp580) on endocrine and paracrine Igf1 and Igfbp3 after stroke. Zfp580 suppressed the expression of Igf1 and Igfbp3 in cerebral microvascular endothelial cells (bEnd.3) as determined by real-time RT-PCR. Zfp580 was suppressed by combined oxygen and glucose deprivation (OGD) and mediated the effect of OGD on Igf1 and Igfbp3. In vivo, we evaluated paracrine regulation by real-time RT-PCR of brain lysates and endocrine regulation by ELISA of blood samples. Genomic ablation of Zfp580 did not alter basal paracrine or endocrine Igf1 and Igfbp3 levels. After transient middle cerebral artery occlusion (MCAo), Zfp580 was globally elevated in the brain for up to 3 days. Paracrine Igf1 and Igfbp3 were selectively induced in the ischemic hemisphere from day 2 to day 3 or day 1 to day 7, respectively. In Zfp580 knockout mice, the paracrine regulations of Igf1 and Igfbp3 were attenuated while endocrine Igf1 and the molar Igf1/Igfbp3 ratio were increased. In conclusion, Zfp580 differentially controls paracrine and endocrine Igf1 and Igfbp3 after stroke. Inhibition of Zfp580 might be a new treatment target leading to increased activity of Igf1 to improve stroke outcome.

Neuroprotective Effect of Physical Activity in Ischemic Stroke: Focus on the Neurovascular Unit

Cerebral ischemia is one of the major diseases associated with death or disability among patients. To date, there is a lack of effective treatments, with the exception of thrombolytic therapy that can be administered during the acute phase of ischemic stroke. Cerebral ischemia can cause a variety of pathological changes, including microvascular basal membrane matrix, endothelial cell activation, and astrocyte adhesion, which may affect signal transduction between the microvessels and neurons. Therefore, researchers put forward the concept of neurovascular unit, including neurons, axons, astrocytes, microvasculature (including endothelial cells, basal membrane matrix, and pericyte), and oligodendrocytes. Numerous studies have demonstrated that exercise can produce protective effects in cerebral ischemia, and that exercise may protect the integrity of the blood-brain barrier, promote neovascularization, reduce neuronal apoptosis, and eventually lead to an improvement in neurological function after cerebral ischemia. In this review, we summarized the potential mechanisms on the effect of exercise on cerebral ischemia, by mainly focusing on the neurovascular unit, with the aim of providing a novel therapeutic strategy for future treatment of cerebral ischemia.

Differential effects of ergometer-cycling and Whole-Body-Vibration training on serological BDNF and IGF-1 in the treatment of adolescent depression - is there an impact of BDNFp.Val66Met variants?

BACKGROUND

Pathogenesis and treatment of adolescent depression may be influenced by growth-factors, including brain-derived neurotrophic factor (BDNF) and insulin-like growth factor 1 (IGF-1). We investigated, if treatment response to two different add-on exercise-therapies in juvenile depression, differ in the changes of BDNF and IGF-1 serology. A subgroup analysis for genetic variations in BDNF p.Val66Met-variants was added.

METHODS

Included subjects in the study (N = 64), aged 13 to 17 years, were diagnosed with major depression, controls received inpatient treatment as usual (TAU). Intervention groups performed as add-on to TAU two different forms of exercise-therapy: endurance ergometer cycling (EC) and muscle strengthening whole body vibration (WBV). We expected both exercise-forms to increase BDNF and IGF-1 serology and by this pathway to improve depression scores significantly stronger than the control group.

RESULTS

None of the experimental groups showed significant changes in BDNF between measurement time points. However, after 6 weeks exercise, BDNF of both intervention groups were significantly higher compared to TAU,. The IGF-1 increase after 6 weeks intervention was significant for EC only. No correlations of BDNF and IGF-1 to depression scores were found. Group analysis in BDNF p.Val66Met variants showed a trend for better response in depression scores to exercise-treatment for the Val66Val group.

LIMITATIONS

A small sample size, the non-randomized controls and the neglect of psychosocial factors have to be considered as limitations.

CONCLUSIONS

Endurance and muscle strengthening trainings seem to influence serological BDNF and IGF-1 differentially. However, the changes in growth factors did not correlate to the decreases in depression scores. BDNF p.Val66Val variant seems to be more receptive for exercise treatment. Identifying biomarkers (growth factors, genetic variants) in adolescent depression could help to develop tailored treatment strategies.

Effects of Aerobic Exercise on Serum Biomarkers of Neuroplasticity and Brain Repair in Stroke: A Systematic Review

OBJECTIVE

To provide a novel overview of the literature and to summarize the evidence for the effects of aerobic exercise (AE) on serum biomarkers neuroplasticity and brain repair in survivors of stroke.

DATA SOURCES

We conducted a systematic review and searched MEDLINE, Embase, and Cochrane CENTRAL using terms related to AE, neuroplasticity, brain repair, and stroke.

STUDY SELECTION

Titles, abstracts, and selected full texts were screened by 2 independent reviewers against the following inclusion criteria: including adult survivors of stroke, completing an AE intervention working within the AE capacity, and measuring at least 1 blood biomarker outcome of interest.

DATA EXTRACTION

Two independent reviewers extracted data and assessed risk of bias using Risk of Bias in Nonrandomized Studies-of Interventions and Cochrane's Risk of Bias 2 tools.

DATA SYNTHESIS

Nine studies (n=215 participants) were included, reporting on the following outcomes: brain-derived neurotrophic factor (BDNF), insulin-like growth factor 1 (IGF-1), vascular endothelial growth factor (VEGF), cortisol, interleukin 6, and myeloperoxidase. A single bout of high-intensity interval training significantly increased BDNF, IGF-1, and VEGF levels, and a 40-45-minute, 24-session, continuous 8-week AE training program significantly increased BDNF levels. No significant difference in response to any other AE intervention was found in other serum biomarkers.

CONCLUSIONS

AE can significantly increase BDNF, IGF-1, and VEGF across different AE protocols in survivors of stroke. However, more research is needed to determine the optimal exercise intensity and modalities, specifically in survivors of acute and subacute stroke, and how this may relate to functional outcomes.

Delayed voluntary physical exercise restores "when" and "where" object recognition memory after traumatic brain injury

Physical exercise has been associated with improved cognition and may even reduce memory deficits after brain injuries. The aims of this work were to: 1) assess whether voluntary physical exercise can reduce the deficits associated with traumatic brain injury (TBI) in two different components of episodic-like memory based on object recognition, temporal order memory ("when"), and object location memory ("where"); and 2) determine whether changes in levels of brain-derived neurotrophic factor (BDNF) in the hippocampus and prefrontal cortex, as well as alterations in hippocampal cytokines, insulin-like growth factor-1 (IGF-1) and vascular endothelial growth factor (VEGF), may influence the effects exercise has on either or both tasks. The rats were distributed into a sham group, a TBI group that remained sedentary (TBI-sed), and a TBI group that had access to a running wheel for a 25-day period from post-injury day 11 (TBI-exe). The rats were sacrificed after the "where" memory task, at post-injury day 37. Physical exercise restored the "when" and "where" memories, which had been impaired by the TBI, and increased the concentration of BDNF in the hippocampus, but not the prefrontal cortex. Neither TBI nor exercise were found to significantly affect hippocampal cytokines, IGF-1 or VEGF at this time post-injury. BDNF levels showed significant positive correlations with exercise, and with "when" (but not "where") memory. These results indicate that post-injury physical exercise restores "when" and "where" object recognition memory tasks after TBI, and that increased BDNF seems to be involved in this effect, particularly with regard to "when" memory.

Effects of Physical Exercise on Neuroplasticity and Brain Function: A Systematic Review in Human and Animal Studies

Background

Physical exercise (PE) has been associated with increase neuroplasticity, neurotrophic factors, and improvements in brain function.

Objective

To evaluate the effects of different PE protocols on neuroplasticity components and brain function in a human and animal model.

Methods

We conducted a systematic review process from November 2019 to January 2020 of the following databases: PubMed, ScienceDirect, SciELO, LILACS, and Scopus. A keyword combination referring to PE and neuroplasticity was included as part of a more thorough search process. From an initial number of 20,782 original articles, after reading the titles and abstracts, twenty-one original articles were included. Two investigators evaluated the abstract, the data of the study, the design, the sample size, the participant characteristics, and the PE protocol.

Results

PE increases neuroplasticity via neurotrophic factors (BDNF, GDNF, and NGF) and receptor (TrkB and P75NTR) production providing improvements in neuroplasticity, and cognitive function (learning and memory) in human and animal models.

Conclusion

PE was effective for increasing the production of neurotrophic factors, cell growth, and proliferation, as well as for improving brain functionality.

A Handful of Details to Ensure the Experimental Reproducibility on the FORCED Running Wheel in Rodents: A Systematic Review

A well-documented method and experimental design are essential to ensure the reproducibility and reliability in animal research. Experimental studies using exercise programs in animal models have experienced an exponential increase in the last decades. Complete reporting of forced wheel and treadmill exercise protocols would help to ensure the reproducibility of training programs. However, forced exercise programs are characterized by a poorly detailed methodology. Also, current guidelines do not cover the minimum data that must be included in published works to reproduce training programs. For this reason, we have carried out a systematic review to determine the reproducibility of training programs and experimental designs of published research in rodents using a forced wheel system. Having determined that most of the studies were not detailed enough to be reproducible, we have suggested guidelines for animal research using FORCED exercise wheels, which could also be applicable to any form of forced exercise.

Role of Regular Physical Activity in Neuroprotection against Acute Ischemia

One of the major obstacles that prevents an effective therapeutic intervention against ischemic stroke is the lack of neuroprotective agents able to reduce neuronal damage; this results in frequent evolution towards a long-term disability with limited alternatives available to aid in recovery. Nevertheless, various treatment options have shown clinical efficacy. Neurotrophins such as brain-derived neurotrophic factor (BDNF), widely produced throughout the brain, but also in distant tissues such as the muscle, have demonstrated regenerative properties with the potential to restore damaged neural tissue. Neurotrophins play a significant role in both protection and recovery of function following neurological diseases such as ischemic stroke or traumatic brain injury. Unfortunately, the efficacy of exogenous administration of these neurotrophins is limited by rapid degradation with subsequent poor half-life and a lack of blood-brain-barrier permeability. Regular exercise seems to be a therapeutic approach able to induce the activation of several pathways related to the neurotrophins release. Exercise, furthermore, reduces the infarct volume in the ischemic brain and ameliorates motor function in animal models increasing astrocyte proliferation, inducing angiogenesis and reducing neuronal apoptosis and oxidative stress. One of the most critical issues is to identify the relationship between neurotrophins and myokines, newly discovered skeletal muscle-derived factors released during and after exercise able to exert several biological functions. Various myokines (e.g., Insulin-Like Growth Factor 1, Irisin) have recently shown their ability to protects against neuronal injury in cerebral ischemia models, suggesting that these substances may influence the degree of neuronal damage in part via inhibiting inflammatory signaling pathways. The aim of this narrative review is to examine the main experimental data available to date on the neuroprotective and anti-ischemic role of regular exercise, analyzing also the possible role played by neurotrophins and myokines.

Applications of Acupuncture Therapy in Modulating the Plasticity of Neurodegenerative Disease and Depression: Do MicroRNA and Neurotrophin BDNF Shed Light on the Underlying Mechanism?

As the global population ages, the incidence of neurodegenerative diseases has risen. Furthermore, it has been suggested that depression, especially in elderly people, may also be an indication of latent neurodegeneration. Stroke, Alzheimer's disease (AD), and Parkinson's disease (PD) are usually accompanied by depression. The urgent challenge is further enforced by psychiatric comorbid conditions, particularly the feeling of despair in these patients. Fortunately, as our understanding of the neurobiological substrates of maladies affecting the central nervous system (CNS) has increased, more therapeutic options and novel potential biological mechanisms have been presented: (1) Neurodegenerative diseases share some similarities in their pathological characteristics, including changes in neuron structure or function and neuronal plasticity. (2) MicroRNAs (miRNAs) are small noncoding RNAs that contribute to the pathogenesis of diverse neurological disease. (3) One ubiquitous neurotrophin, brain-derived neurotrophic factor (BDNF), is crucial for the development of the nervous system. Accumulating data have indicated that miRNAs not only are related to BDNF regulation but also can directly bind with the 3'-UTR of BDNF to regulate BDNF and participate in neuroplasticity. In this short review, we present evidence of shared biological substrates among stroke, AD, PD, and depression and summarize the possible influencing mechanisms of acupuncture on the neuroplasticity of these diseases. We discuss neuroplasticity underscored by the roles of miRNAs and BDNF, which might further reveal the potential biological mechanism of neurodegenerative diseases and depression by acupuncture.

Individualized Running Wheel System with a Dynamically Adjustable Exercise Area and Speed for Rats Following Ischemic Stroke

Background

An innovative animal running wheel with an individualized design was implemented for the rehabilitation of rats following ischemic stroke.

Material/Methods

The design of the running wheel platform included the running wheel and a side plate for exercise area adjustments. A U-curve with a width of 2 cm was drawn on the lower half of the side plate for the dynamic adjustments of five infrared (IR) sensors based on the physical fitness of the rats. The individualized training process for this running wheel consisted of 2 days of free training to record their average and maximum speeds, 3 days of progressive training to determine their exercise areas, and 2 weeks of normal training based on their average speeds, maximum speeds, and exercise areas. Blood samples were obtained from the tail veins of all rats before the operations and on Days 14, 21, and 28 postsurgery to measure cortisol levels. The motor function tests were performed on Days 7 and 28 postsurgery. On Day 28 postsurgery, the rats were sacrificed under anesthesia, and their brains were removed for Nissl and H&E staining.

Results

On Day 28 after surgery, the motor function, lesion volume, and cell damage of the DEARW and control groups differed significantly, indicating that this device is effective for stroke rehabilitation.

Conclusions

The outcomes of the rats that were rehabilitated using the newly designed training system were better than those of their control-group counterparts, indicating the advantages of this designed system.

Cognitive Impairments of Sleep-Deprived Ovariectomized (OVX) Female Rats by Voluntary Exercise

Introduction:

Previous studies demonstrated that forced and voluntary exercise had ameliorative effects on behavioral tasks followed by Sleep Deprivation (SD) in intact female rats. The main goal of this research was evaluating the impact of voluntary exercise on cognitive functions while SD and ovariectomization is induced in female wistar rats.

Methods:

The rats were anesthesized combining dosage of ketamine and xylazine. Then, both ovaries were eliminated and 3 weeks after surgery the animals entered the study. The exercise protocol took 4 weeks of voluntary exercise in a wheel which was connected to home cage. For inducing a 72 hours deprivation the multiple platforms was applied. The cognitive functions were studied by exploiting the Morris Water Maze (MWM) and Novel object recognition tests. Anxiety was evaluated by open field test and corticostrone measurement was carried out by ELISA method. One-way and two-way ANOVA and repeated measures were utilized for data analysis and P<0.05 was considered statistically significant.

Results:

We observed significant spatial and recognition learning and memory impairments in OVX sleep-deprived rats compared to the control group and voluntary exercise alleviated the SD-induced learning and memory defects.

Conclusion:

We concluded that voluntary exercise can improve cognitive impairments followed by SD in OVX female rats.

A Review of Exercise-Induced Neuroplasticity in Ischemic Stroke: Pathology and Mechanisms

After ischemic stroke, survivors experience motor dysfunction and deterioration of memory and cognition. These symptoms are associated with the disruption of normal neuronal function, i.e., the secretion of neurotrophic factors, interhemispheric connections, and synaptic activity, and hence the disruption of the normal neural circuit. Exercise is considered an effective and feasible rehabilitation strategy for improving cognitive and motor recovery following ischemic stroke through the facilitation of neuroplasticity. In this review, our aim was to discuss the mechanisms by which exercise-induced neuroplasticity improves motor function and cognitive ability after ischemic stroke. The associated mechanisms include increases in neurotrophins, improvements in synaptic structure and function, the enhancement of interhemispheric connections, the promotion of neural regeneration, the acceleration of neural function reorganization, and the facilitation of compensation beyond the infarcted tissue. We also discuss some common exercise strategies and a novel exercise therapy, robot-assisted movement, which might be widely applied in the clinic to help stroke patients in the future.

Development of a three-channel automatic climbing training system for rat rehabilitation after ischemic stroke

This paper reports the development of a three-channel automatic speed-matching climbing training system that could train three rats at the same time for rehabilitation after an ischemic stroke. An infrared (IR) remote sensor was installed at the end of each channel to monitor the real-time position of a climbing rat. This research was carried out in five stages: i) system design; ii) hardware circuit; iii) running speed control; iv) functional testing; and v) verification using an animal model of cerebral stroke. The rehabilitated group significantly outperformed the middle cerebral artery occlusion (MCAo) sedentary group in the rota-rod and inclined plate tests 21 days after a stroke. The rehabilitated group also had a cerebral infarction volume of 28.34±19.4%, far below 56.81±18.12% of the MCAo group 28 days after the stroke, validating the effectiveness of this training platform for stroke rehabilitation. The running speed of the climbing rehabilitation training platform was designed to adapt to the physical conditions of subjects, and overtraining injuries can be completely prevented accordingly.

Intensity-dependent effects of consecutive treadmill exercise on spatial learning and memory through the p-CREB/BDNF/NMDAR signaling in hippocampus

Exercise is the most recommended non-pharmacological intervention to improve neurocognitive functions under physiological and pathological conditions. However, it remains to be elucidated concerning the influence and the underlying neurological molecular mechanism of different exercise intensity on cognitive function. In this study, we aimed to explore the effects of exercise intensity on spatial learning and memory, as well as the regulation of brain-derived neurotrophic factor (BDNF)/p-CREB/NMDAR signal. In the research, low-intensity consecutive treadmill (LICT) and high-intensity consecutive treadmill (HICT) were implied to rats for 8 weeks. We found that the performances in the Morris water maze were improved in the LICT group, while reduced in the HICT group as compared with the sedentary rats. Moreover, the expression of BDNF mRNA, phosphorylation cAMP-response-element binding protein (p-CREB), mature BDNF (mBDNF), tropomyosin receptor kinase B (TrkB), tissue plasminogen activator (t-PA), and NR2B proteins was increased, whereas the expression of precursor BDNF (proBDNF) and pan-neurotrophin receptor 75 (p75NTR) proteins was decreased in the hippocampus of LICT group compared with the sedentary rats. On the contrary, the expression of proteins and mRNA aforementioned in the LICT group showed a reversed tendency in the hippocampus of HICT rats. These findings suggest that the consecutive low-intensity exercise and high-intensity exercise exert different effects on spatial learning and memory by oppositely regulating the mutual stimulation of p-CREB and BDNF mRNA feedback loop, as well as the t-PA/BDNF/NMDAR which is the post-translation cascades of BDNF signaling.

Astrocyte-derived extracellular vesicles: Neuroreparative properties and role in the pathogenesis of neurodegenerative disorders

Extracellular vesicles (EVs) released by neural cells play an essential role in brain homeostasis and the crosstalk between neural cells and the periphery. EVs are diverse, nano-sized vesicles, which transport proteins, nucleic acids, and lipids between cells over short and long expanses and hence are proficient for modulating the target cells. EVs released from neural cells are implicated in synaptic plasticity, neuron-glia interface, neuroprotection, neuroregeneration, and the dissemination of neuropathological molecules. This review confers the various properties of EVs secreted by astrocytes and their potential role in health and disease with a focus on evolving concepts. Naïve astrocytes shed EVs containing a host of neuroprotective compounds, which include fibroblast growth factor-2, vascular endothelial growth factor, and apolipoprotein-D. Stimulated astrocytes secrete EVs with neuroprotective molecules including heat shock proteins, synapsin 1, unique microRNAs, and glutamate transporters. Well-characterized astrocyte-derived EVs (ADEVs) generated in specific culture conditions and ADEVs that are engineered to carry the desired miRNAs or proteins are likely useful for treating brain injury and neurogenerative diseases. On the other hand, in conditions such as Alzheimer's disease (AD), stroke, Parkinson's disease, Amyotrophic lateral sclerosis (ALS), and other neuroinflammatory conditions, EVs released by activated astrocytes appear to mediate or exacerbate the pathological processes. The examples include ADEVs spreading the dysregulated complement system in AD, mediating motoneuron toxicity in ALS, and stimulating peripheral leukocyte migration into the brain in inflammatory conditions. Strategies restraining the release of EVs by activated astrocytes or modulating the composition of ADEVs are likely beneficial for treating neurodegenerative diseases. Also, periodic analyses of ADEVs in the blood is useful for detecting astrocyte-specific biomarkers in different neurological conditions and for monitoring disease progression and remission with distinct therapeutic approaches.

Exercise Plus Pharmacological Neuromodulation of Synaptic Inhibition Enhance Motor Function Recovery After Ischemic Stroke

The objective of this study was to examine the interactive effects of exercise and low-level inhibition of GABA_A receptors on the recovery of motor function and BDNF expression in the primary motor cortex (M1) of a stroke rat model. Male Sprague-Dawley rats were divided into five groups: sham (SHAM), control (CON), exercise (EX), bicuculline (BIC), and bicuculline plus exercise (BICEX) groups. All rats, except those in the SHAM group, underwent middle cerebral artery occlusion (MCAO) surgery to induce an ischemic stroke. GABA_A receptor antagonist, bicuculline (0.25 mg/kg, i.p.), was administered to the BIC and BICEX groups. The EX and BICEX groups exercised on a treadmill (11 m/min for 30 min). Each intervention started 3 days after the MCAO surgery and was carried out every day for 2 weeks. Following the intervention, bilateral M1 BDNF mRNA and protein expression levels were assessed using qRT-PCR and ELISA. Marginal recovery was found in the EX and BIC groups, whereas motor function recovery was enhanced with exercise in the presence of BIC administration specifically in the BICEX group. Furthermore, BDNF protein level in the ipsilateral M1 was significantly higher in the BICEX group than in other groups. This study indicated that exercise combined with low-level inhibition of GABA_A receptors after stroke could facilitate the recovery of motor function accompanied by BDNF upregulation in the ipsilateral M1. Therefore, this study provides a novel insight of pharmacological neuromodulation into stroke rehabilitation.

An enriched environment increases the expression of fibronectin type III domain-containing protein 5 and brain-derived neurotrophic factor in the cerebral cortex of the ischemic mouse brain

Many studies have shown that fibronectin type III domain-containing protein 5 (FDNC5) and brain-derived neurotrophic factor (BDNF) play vital roles in plasticity after brain injury. An enriched environment refers to an environment that provides animals with multi-sensory stimulation and movement opportunities. An enriched environment has been shown to promote the regeneration of nerve cells, synapses, and blood vessels in the animal brain after cerebral ischemia; however, the exact mechanisms have not been clarified. This study aimed to determine whether an enriched environment could improve neurobehavioral functions after the experimental inducement of cerebral ischemia and whether neurobehavioral outcomes were associated with the expression of FDNC5 and BDNF. This study established ischemic mouse models using permanent middle cerebral artery occlusion (pMCAO) on the left side. On postoperative day 1, the mice were randomly assigned to either enriched environment or standard housing condition groups. Mice in the standard housing condition group were housed and fed under standard conditions. Mice in the enriched environment group were housed in a large cage, containing various toys, and fed with a standard diet. Sham-operated mice received the same procedure, but without artery occlusion, and were housed and fed under standard conditions. On postoperative days 7 and 14, a beam-walking test was used to assess coordination, balance, and spatial learning. On postoperative days 16–20, a Morris water maze test was used to assess spatial learning and memory. On postoperative day 15, the expression levels of FDNC5 and BDNF proteins in the ipsilateral cerebral cortex were analyzed by western blot assay. The results showed that compared with the standard housing condition group, the motor balance and coordination functions (based on beam-walking test scores 7 and 14 days after operation), spatial learning abilities (based on the spatial learning scores from the Morris water maze test 16–19 days after operation), and memory abilities (based on the memory scores of the Morris water maze test 20 days after operation) of the enriched environment group improved significantly. In addition, the expression levels of FDNC5 and BDNF proteins in the ipsilateral cerebral cortex increased in the enriched environment group compared with those in the standard housing condition group. Furthermore, the Pearson correlation coefficient showed that neurobehavioral functions were positively associated with the expression levels of FDNC5 and BDNF (r = 0.587 and r = 0.840, respectively). These findings suggest that an enriched environment upregulates FDNC5 protein expression in the ipsilateral cerebral cortex after cerebral ischemia, which then activates BDNF protein expression, improving neurological function. BDNF protein expression was positively correlated with improved neurological function. The experimental protocols were approved by the Institutional Animal Care and Use Committee of Fudan University, China (approval Nos. 20160858A232, 20160860A234) on February 24, 2016.

Acute forced exercise increases Bdnf IV mRNA and reduces exploratory behavior in C57BL/6J mice

Acute exercise has been shown to improve memory in humans. Potential mechanisms include increased Bdnf expression, noradrenergic activity and modification of glutamate receptors. Because mice are commonly used to study exercise and brain plasticity, it is important to explore how acute exercise impacts behavior in this model. C57BL/6J mice were assigned to three groups: control, moderate-intensity running, and high-intensity running. Control mice were placed on a stationary treadmill for 30 minutes and moderate- and high-intensity mice ran for 30 minutes at 12 and 15-17 m/min, respectively. Mice were sacrificed immediately after running and the hippocampus removed. Total Bdnf, Bdnf exon IV, and glutamate receptor subunits were quantified with quantitative polymerase chain reaction. Total and phosphorylated GluR1 (Ser845 and Ser831) protein was quantified following immunoblotting. Utilizing the same protocol for control and high-intensity running, object location memory was examined in a separate cohort of mice. Anxiety-like behavior was assessed in the open field task (OFT) in a third cohort of mice that were separated into four groups: control-saline, control-DSP-4, acute exercise-saline, and acute exercise-DSP-4. DSP-4 was used to lesion the central noradrenergic system. We observed higher Bdnf IV mRNA in high-intensity runners compared to controls, but no effects of acute exercise on memory. In the OFT, runners traveled less distance and spent more time grooming than controls. DSP-4 did not attenuate the effects of exercise. A single bout of exercise increases Bdnf IV mRNA in an intensity-dependent manner; however, high-intensity running reduces exploratory behavior in C57BL/6J mice.

Remarkable cell recovery from cerebral ischemia in rats using an adaptive escalator-based rehabilitation mechanism

Currently, many ischemic stroke patients worldwide suffer from physical and mental impairments, and thus have a low quality of life. However, although rehabilitation is acknowledged as an effective way to recover patients’ health, there does not exist yet an adaptive training platform for animal tests so far. For this sake, this paper aims to develop an adaptive escalator (AE) for rehabilitation of rats with cerebral ischemia. Rats were observed to climb upward spontaneously, and a motor-driven escalator, equipped with a position detection feature and an acceleration/deceleration mechanism, was constructed accordingly as an adaptive training platform. The rehabilitation performance was subsequently rated using an incline test, a rotarod test, the infarction volume, the lesion volume, the number of MAP2 positive cells and the level of cortisol. This paper is presented in 3 parts as follows. Part 1 refers to the escalator mechanism design, part 2 describes the adaptive ladder-climbing rehabilitation mechanism, and part 3 discusses the validation of an ischemic stroke model. As it turned out, a rehabilitated group using this training platform, designated as the AE group, significantly outperformed a control counterpart in terms of a rotarod test. After the sacrifice of the rats, the AE group gave an average infarction volume of (34.36 ± 3.8)%, while the control group gave (66.41 ± 3.1)%, validating the outperformance of the escalator-based rehabilitation platform in a sense. An obvious difference between the presented training platform and conventional counterparts is the platform mechanism, and for the first time in the literature rats can be well and voluntarily rehabilitated at full capacity using an adaptive escalator. Taking into account the physical diversity among rats, the training strength provided was made adaptive as a reliable way to eliminate workout or secondary injury. Accordingly, more convincing arguments can be made using this mental stress-free training platform.

Therapeutic effects of combined cell transplantation and locomotor training in rats with brain injury

Cell-based therapies are attracting attention as alternative therapeutic options for brain damage. In this study, we investigated the therapeutic effect of a combined therapy of cell transplantation and locomotor training by evaluating the neuronal connectivity. We transplanted neural cells derived from the frontal cortex of E14.5 GFP-expressing mice into the frontal lobe of 3-week-old rats with brain injury, followed by treadmill training (TMT) for 14 days. In the TMT(-) group, graft-derived neurites were observed only in the striatum and internal capsule. In contrast, in the TMT(+) group, they were observed in the striatum, internal capsule, and the cerebral peduncle and spinal cord. The length of the longest neurite was significantly longer in the TMT(+) group than in the TMT(-) group. In the TMT(+) group, Synaptophysin⁺ vesicles on the neuronal fibers around the ipsilateral red nucleus were found, suggesting that neuronal fibers from the grafted cells formed synapses with the host neurons. A functional analysis of motor recovery using the foot fault test showed that, 1 week after the transplantation, the recovery was significantly better in the cell transplantation and TMT group than the cell transplantation only group. The percentage of cells expressing C-FOS was increased in the grafts in the TMT(+) group. In conclusion, TMT promoted neurite extensions from the grafted neural cells, and the combined therapy of cell transplantation and locomotor training might have the potential to promote the functional recovery of rats with brain injury compared to cell transplantation alone.

Synergistic Benefits of Combined Aerobic and Cognitive Training on Fluid Intelligence and the Role of IGF-1 in Chronic Stroke

BACKGROUND

Paired exercise and cognitive training have the potential to enhance cognition by "priming" the brain and upregulating neurotrophins.

METHODS

Two-site randomized controlled trial. Fifty-two patients >6 months poststroke with concerns about cognitive impairment trained 50 to 70 minutes, 3× week for 10 weeks with 12-week follow-up. Participants were randomized to 1 of 2 physical interventions: Aerobic (>60% VO_2peak using <10% body weight-supported treadmill) or Activity (range of movement and functional tasks). Exercise was paired with 1 of 2 cognitive interventions (computerized dual working memory training [COG] or control computer games [Games]). The primary outcome for the 4 groups (Aerobic + COG, Aerobic + Games, Activity + COG, and Activity + Games) was fluid intelligence measured using Raven's Progressive Matrices Test administered at baseline, posttraining, and 3-month follow-up. Serum neurotrophins collected at one site (N = 30) included brain-derived neurotrophic factor (BDNF) at rest (BDNF_resting) and after a graded exercise test (BDNF_response) and insulin-like growth factor-1 at the same timepoints (IGF-1_rest, IGF-1_response).

RESULTS

At follow-up, fluid intelligence scores significantly improved compared to baseline in the Aerobic + COG and Activity + COG groups; however, only the Aerobic + COG group was significantly different (+47.8%) from control (Activity + Games -8.5%). Greater IGF-1_response at baseline predicted 40% of the variance in cognitive improvement. There was no effect of the interventions on BDNF_resting or BDNF_response; nor was BDNF predictive of the outcome.

CONCLUSIONS

Aerobic exercise combined with cognitive training improved fluid intelligence by almost 50% in patients >6 months poststroke. Participants with more robust improvements in cognition were able to upregulate higher levels of serum IGF-1 suggesting that this neurotrophin may be involved in behaviorally induced plasticity.

Serum levels of insulin-like growth factor-1 and brain-derived neurotrophic factor as potential recovery biomarkers in stroke

OBJECTIVES

Our objectives were: 1) to determine whether maximal aerobic exercise increased serum neurotrophins in chronic stroke and 2) to determine the factors that predict resting and exercise-dependent levels.

METHODS

We investigated the potential predictors of resting and exercise-dependent serum insulin-like growth factor-1 and brain-derived neurotrophic factor among 35 chronic stroke patients. Predictors from three domains (demographic, disease burden, and cardiometabolic) were entered into 4 separate stepwise linear regression models with outcome variables: resting insulin-like growth factor, resting brain-derived neurotrophic factor, exercise-dependent change in insulin-like growth factor, and exercise-dependent change brain-derived neurotrophic factor.

RESULTS

Insulin-like growth factor decreased after exercise (p = 0.001) while brain-derived neurotrophic factor did not change (p = 0.38). Greater lower extremity impairment predicted higher resting brain-derived neurotrophic factor (p = 0.004, r² = 0.23). Higher fluid intelligence predicted greater brain-derived neurotrophic factor response to exercise (p = 0.01, r² = 0.18). There were no significant predictors of resting or percent change insulin-like growth factor-1.

DISCUSSION

Biomarkers have the potential to characterize an individual's potential for recovery from stroke. Neurotrophins such as insulin-like growth factor-1 and brain-derived neurotrophic factor are thought to be important in neurorehabilitation; however, the factors that modulate these biomarkers are not well understood. Resting brain-derived neurotrophic factor and percent change in brain-derived neurotrophic factor were related to physical and cognitive recovery in chronic stroke, albeit weakly. Insulin-like growth factor-1 was not an informative biomarker among chronic stroke patients. The novel finding that fluid intelligence positively correlated with exercise-induced change in brain-derived neurotrophic factor warrants further research.

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.

Exercise Reduces Dopamine D1R and Increases D2R in Rats: Implications for Addiction

INTRODUCTION

Exercise has been shown to be effective for preventing and treating substance abuse in both clinical and preclinical studies. Less is known, however, regarding the underlying neurobiological mechanisms driving these changes in drug-seeking behavior. One possibility is that exercise may alter the mesolimbic dopamine pathway in such a way that makes drugs of abuse less salient and/or rewarding.

METHODS

To examine possible exercise-induced changes in dopamine signaling, male and female Lewis rats were split into exercise and sedentary groups at 8 wk of age. Exercise rats were run on a treadmill at 10 m·min, 5 d·wk, for 6 wk, whereas sedentary rats remained in their home cage. Rats were killed after the 6 wk of treatment, and their brains were used for in vitro autoradiography using [H]SCH 23,390, [H]Spiperone, and [H]WIN55,428 ligands to quantify dopamine type 1-like receptor (D1R)-like, dopamine type 2-like receptor (D2R)-like, and dopamine transporter binding, respectively.

RESULTS

Exercised rats had 18% and 21% lower D1R-like binding levels compared to sedentary rats within the olfactory tubercle and nucleus accumbens shell, respectively. In addition, male and female exercise rats showed greater D2R-like binding levels within the dorsomedial caudate putamen (30%), ventrolateral caudate putamen (24%), and ventromedial caudate putamen (27%), as well as the olfactory tubercle (19%). Greater D2R-like binding in the nucleus accumbens core (24%) and shell (25%) of exercised rats compared with sedentary rats approached significance. No effects were found for dopamine transporter binding.

CONCLUSIONS

These findings support the hypothesis that aerobic exercise results in changes in the mesolimbic pathway that could mediate exercise-induced attenuation of drug-seeking behavior.

Chronic forced exercise inhibits stress-induced reinstatement of cocaine conditioned place preference

Stress increases the likelihood of cocaine relapse in humans and animals, even following a prolonged extinction/abstinence period. Exercise has previously been shown to reduce stress and decrease the likelihood of drug dependence, while also reducing cravings in humans and inhibiting relapse behaviors due to other risk factors in rodents. The present study evaluated the efficacy of exercise to reduce stress-induced relapse to cocaine in a rodent model. Young adult female Sprague Dawley rats were tested for cocaine conditioned place preference (CPP), then split into sedentary or exercise (six weeks of one-hour daily treadmill running, five days per week) groups. Following cocaine CPP, rats were tested for extinction behavior, and then tested for stress-primed reinstatement (15 min immobilization) following the six-week intervention period. Exercise inhibited stress-induced reinstatement of cocaine CPP despite increasing serum corticosterone levels following 15 min of immobilization, suggesting that chronic aerobic exercise intervention may result in adaptations of stress pathways. These findings suggest that exercise may help prevent stress-induced drug relapse, adding to a growing body of evidence supporting the utility of exercise to combat substance abuse.

A Bout of High Intensity Interval Training Lengthened Nerve Conduction Latency to the Non-exercised Affected Limb in Chronic Stroke

Objective: Evaluate intensity-dependent effects of a single bout of high intensity interval training (HIIT) compared to moderate intensity constant-load exercise (MICE) on corticospinal excitability (CSE) and effects on upper limb performance in chronic stroke.

Design: Randomized cross-over trial.

Setting: Research laboratory in a tertiary rehabilitation hospital.

Participants: Convenience sample of 12 chronic stroke survivors.

Outcome measures: Bilateral CSE measures of intracortical inhibition and facilitation, motor thresholds, and motor evoked potential (MEP) latency using transcranial magnetic stimulation. Upper limb functional measures of dexterity (Box and Blocks Test) and strength (pinch and grip strength).

Results: Twelve (10 males; 62.50 ± 9.0 years old) chronic stroke (26.70 ± 23.0 months) survivors with moderate level of residual impairment participated. MEP latency from the ipsilesional hemisphere was lengthened after HIIT (pre: 24.27 ± 1.8 ms, and post: 25.04 ± 1.8 ms, p = 0.01) but not MICE (pre: 25.49 ± 1.10 ms, and post: 25.28 ± 1.0 ms, p = 0.44). There were no significant changes in motor thresholds, intracortical inhibition or facilitation. Pinch strength of the affected hand decreased after MICE (pre: 8.96 ± 1.9 kg vs. post: 8.40 ± 2.0 kg, p = 0.02) but not after HIIT (pre: 8.83 ± 2.0 kg vs. post: 8.65 ± 2.2 kg, p = 0.29). Regardless of type of aerobic exercise, higher total energy expenditure was associated with greater increases in pinch strength in the affected hand after exercise (R² = 0.31, p = 0.04) and decreases in pinch strength of the less affected hand (R² = 0.26 p = 0.02).

Conclusion: A single bout of HIIT resulted in lengthened nerve conduction latency in the affected hand that was not engaged in the exercise. Longer latency could be related to the cross-over effects of fatiguing exercise or to reduced hand spasticity. Somewhat counterintuitively, pinch strength of the affected hand decreased after MICE but not HIIT. Regardless of the structure of exercise, higher energy expended was associated with pinch strength gains in the affected hand and strength losses in the less affected hand. Since aerobic exercise has acute effects on MEP latency and hand strength, it could be paired with upper limb training to potentiate beneficial effects.

40 YEARS of IGF1: IGF1: the Jekyll and Hyde of the aging brain

The insulin-like growth factor 1 (IGF1) signaling pathway has emerged as a major regulator of the aging process, from rodents to humans. However, given the pleiotropic actions of IGF1, its role in the aging brain remains complex and controversial. While IGF1 is clearly essential for normal development of the central nervous system, conflicting evidence has emerged from preclinical and human studies regarding its relationship to cognitive function, as well as cerebrovascular and neurodegenerative disorders. This review delves into the current state of the evidence examining the role of IGF1 in the aging brain, encompassing preclinical and clinical studies. A broad examination of the data indicates that IGF1 may indeed play opposing roles in the aging brain, depending on the underlying pathology and context. Some evidence suggests that in the setting of neurodegenerative diseases that manifest with abnormal protein deposition in the brain, such as Alzheimer's disease, reducing IGF1 signaling may serve a protective role by slowing disease progression and augmenting clearance of pathologic proteins to maintain cellular homeostasis. In contrast, inducing IGF1 deficiency has also been implicated in dysregulated function of cognition and the neurovascular system, suggesting that some IGF1 signaling may be necessary for normal brain function. Furthermore, states of acute neuronal injury, which necessitate growth, repair and survival signals to persevere, typically demonstrate salutary effects of IGF1 in that context. Appreciating the dual, at times opposing 'Dr Jekyll' and 'Mr Hyde' characteristics of IGF1 in the aging brain, will bring us closer to understanding its impact and devising more targeted IGF1-related interventions.

Whole body vibration added to treatment as usual is effective in adolescents with depression: a partly randomized, three-armed clinical trial in inpatients

There is growing evidence for the effectiveness of exercise in the treatment of adult major depression. With regard to adolescents, clinical trials are scarce. Due to the inherent symptoms of depression (lack of energy, low motivation to exercise), endurance training forms could be too demanding especially in the first weeks of treatment. We hypothesized that an easy-to-perform passive muscular training on a whole body vibration (WBV) device has equal anti-depressive effects compared to a cardiovascular training, both administered as add-ons to treatment as usual (TAU). Secondly, we presumed that both exercise interventions would be superior in their response, compared to TAU. In 2 years 64 medication-naïve depressed inpatients aged 13-18, were included. Both exercise groups fulfilled a supervised vigorous training for 6 weeks. Depressive symptoms were assessed by self-report ("Depressions Inventar für Kinder und Jugendliche"-DIKJ) before intervention and after weeks 6, 14 and 26. Compared to TAU, both groups responded earlier and more strongly measured by DIKJ scores, showing a trend for the WBV group after week 6 (p = 0.082). The decrease became statistically significant for both intervention groups after week 26 (p = 0.037 for ergometer and p = 0.042 for WBV). Remission rates amounted to 39.7% after week 6 and 66% after week 26, compared to 25% after week 26 in TAU. These results provide qualified support for the effectiveness of exercise as add-on treatment for medication-naïve depressed adolescents. The present results are limited by the not randomized control group.

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.