Aerobic exercise alleviates ischemia-induced memory impairment by enhancing cell proliferation and suppressing neuronal apoptosis in hippocampus

Rehabilitation training enhanced the therapeutic effect of calycosin on neurological function recovery of rats following spinal cord injury

BACKGROUND

Calycosin (CA), a flavonoids component, has demonstrated potential neuroprotection effects by inhibiting oxidative stress in spinal cord injury (SCI) models. This study aims to investigate the impact of combined rehabilitation training (RT) and calycosin therapy on neurological function following SCI, primarily by assessing changes in motor function recovery, neuronal survival, neuronal oxidative stress levels, and neural proliferation, in order to provide novel insights for the treatment of SCI.

MATERIALS AND METHODS

The SCI model was constructed by compressing the spinal cord using vascular clamps. Calycosin was injected intraperitoneally into the SCI model rats, and a group of 5 rats underwent RT. The motor function of rats after SCI was evaluated using the Basso Beattle Bresnaha (BBB) score and the inclined plate test. Histopathological changes were evaluated by NeuN immunohistochemistry, HE and Nissl staining. Apoptosis was detected by TUNEL staining. The antioxidant effect of combined treatment was assessed by measuring changes in oxidative stress markers after SCI. Western blot analysis was conducted to examine changes in Hsp90-Akt/ASK1-p38 pathway-related proteins. Finally, cell proliferation was detected by BrdU and Ki67 assays.

RESULTS

RT significantly improved the BBB score and angle of incline promoted by calycosin, resulting in enhanced motor function recovery in rats with SCI. Combining rehabilitation training with calycosin has a positive effect on morphological recovery. Similarly, combined RT enhanced the Nissl and NeuN staining signals of spinal cord neurons increased by calycosin, thereby increasing the number of neurons. TUNEL staining results indicated that calycosin treatment reduced the apoptosis signal in SCI, and the addition of RT further reduced the apoptosis. Moreover, RT combined with calycosin reduced oxidative stress by increasing SOD and GSH levels, while decreasing MDA, NO, ROS, and LDH expressions compared to the calycosin alone. RT slightly enhanced the effect of calycosin in activating Hsp90 and Akt and inhibiting the activation of ASK1 and p38, leading to enhanced inhibition of oxidative stress by calycosin. Additionally, the proliferation indexes (Ki67 and BrdU) assays showed that calycosin treatment alone increased both, whereas the combination treatment further promoted cell proliferation.

CONCLUSION

Our research findings demonstrate that rehabilitation training enhances the ability of calycosin to reduce oxidative stress, resulting in a decrease in neuronal apoptosis and an increase in proliferation, ultimately promoting neuronal survival.

Aerobic exercise training reduces deep-frying oil-induced apoptosis of hippocampal tissue by reducing oxidative stress in male rats

Deep-frying oil (DFO) contains high amounts of free radicals, and consuming foods prepared with this method causes damage to nervous tissue due to oxidative stress (OS). Since moderate-intensity aerobic exercise training (AT) reduces OS, the current search investigated the effects of AT on OS, apoptosis, and neurogenesis markers in the hippocampal tissue of DFO-fed rats. Eighteen Wistar male rats (200-280 gr) were randomly allocated to a control group fed with normal food (Con-ND), a control group receiving DFO (Con-DFO), and a group receiving DFO-aerobic exercise (EX-DFO) (n = 6 in each). DFO was gavaged for four weeks, five days a week, with a dose of 2 ml. AT included running on a treadmill for four weeks and five sessions per week (40 min per session). The expression of genes B-cell lymphoma 2 (BCL-2), Protein X associated with Bcl-2 (BAX), Caspase-3 (Casp-3), and Caspase-9 (Casp-9) was measured by PCR method. The ELISA method was used to calculate levels of Superoxide dismutase (SOD) and Catalase (CAT) activity, malondialdehyde (MDA), and Brain-Derived Neurotrophic Factor (BDNF). Also, the expression of the proteins Cannabinoid receptor type 1(CB1), Cannabinoid receptor type2 (CB2), Glial fibrillary acidic protein (GFAP), Neuronal nuclei (NeuN), and DNA fragmentation was evaluated by Immunohistochemical and TUNEL staining. DFO feeding led to a significant increase in apoptotic markers, such as BAX, Casp-3, and Casp-9 gene expression, and DNA fragmentation (p ≤ 0.05) while decreasing BDNF concentration SOD activity (p ≤ 0.05). AT significantly reduced the BAX, Casp-3, Casp-9, MDA, CB1, GFAP, and DNA fragmentation (p ≤ 0.05). In conclusion, AT can reduce the harmful effects of feeding with DFO on the hippocampal tissue.

Very early environmental enrichment protects against apoptosis and improves functional recovery from hypoxic-ischemic brain injury

Appropriate rehabilitation of stroke patients at a very early phase results in favorable outcomes. However, the optimal strategy for very early rehabilitation is at present unclear due to the limited knowledge on the effects of very early initiation of rehabilitation based on voluntary exercise (VE). Environmental enrichment (EE) is a therapeutic paradigm for laboratory animals that involves complex combinations of physical, cognitive, and social stimuli, as well as VE. Few studies delineated the effect of EE on apoptosis in very early stroke in an experimental model. Although a minimal benefit of early rehabilitation in stroke models has been claimed in previous studies, these were based on a forced exercise paradigm. The aim of this study is to determine whether very early exposure to EE can effectively regulate Fas/FasL-mediated apoptosis following hypoxic-ischemic (HI) brain injury and improve neurobehavioral function. C57Bl/6 mice were housed for 2 weeks in either cages with EE or standard cages (SC) 3 h or 72 h after HI brain injury. Very early exposure to EE was associated with greater improvement in motor function and cognitive ability, reduced volume of the infarcted area, decreased mitochondria-mediated apoptosis, and decreased oxidative stress. Very early exposure to EE significantly downregulated Fas/FasL-mediated apoptosis, decreased expression of Fas, Fas-associated death domain, cleaved caspase-8/caspase-8, cleaved caspase-3/caspase-3, as well as Bax and Bcl-2, in the cerebral cortex and the hippocampus. Delayed exposure to EE, on the other hand, failed to inhibit the extrinsic pathway of apoptosis. This study demonstrates that very early exposure to EE is a potentially useful therapeutic translation for stroke rehabilitation through effective inhibition of the extrinsic and intrinsic apoptotic pathways.

Bringing High-Dose Neurorestorative Behavioral Training Into the Acute Stroke Unit

ABSTRACT

Stroke remains common and is a leading cause of adult disability. While there have been enormous system changes for the diagnosis and delivery of hyperacute stroke treatments at comprehensive stroke centers, few advances have been made in those same centers for treatments focused on behavioral recovery and brain repair. Specifically, during the early hospital period, there is a paucity of approaches available for reduction of impairment beyond what is expected from spontaneous biological recovery. Thus, patients in the early stroke recovery period are not receiving the kind of training needed, at the requisite intensity and dose, to exploit a potential critical period of heightened brain plasticity that could maximize true recovery instead of just compensation. Here, we describe an ongoing pilot program to reconfigure the acute stroke unit experience to allow for a new emphasis on brain repair. More specifically, we have introduced a novel room-based video-gaming intervention; restorative neuroanimation, into the acute stroke hospital setting. This new intervention provides the opportunity for an extra hour(s) of high-intensity neurorestorative behavioral treatment that is complementary to conventional rehabilitation. To accomplish this, system redesign was required to insert this new treatment into the patient day, to properly stratify patients behaviorally and physiologically for the treatment, to optimize the digital therapeutic approach itself, and to maintain the impairment reduction after discharge.

Exercise on Striatal Dopamine Level and Anxiety-Like Behavior in Male Rats after 2-VO Cerebral Ischemia

The purpose of this study was to discuss the effect of voluntary wheel running on striatal dopamine levels and anxiety-like behavior in rats with global cerebral ischemia. The male Sprague-Dawley rats were signed on in this study and randomly divided into following 4 groups: Control group (C group), Sham group (S group), ischemia group (I group), and 3 weeks physical exercise before ischemia group (3RI group). The rats in the 3RI group were placed in a voluntary running wheel for three weeks to exercise. Then, the rats in I and 3RI groups received bilateral carotid artery ligation (2-VO) operation. The C and S group did not perform voluntary running exercise and the bilateral common carotid arteries of S group were exposed without ligation. In vivo microdialysis was used in conjunction with high performance liquid chromatography (HPLC) and electrochemical detection to ascertain the level of dopamine in the striatum. Elevated plus maze (EPM) and open field (OF) were used to test anxiety status at 24 hours and 7days after 2-VO cerebral ischemia. Meanwhile, gait and motor coordination evaluations were carried out to eliminate the influence of non-specific motor problems. The results indicated that cerebral ischemia instigate the increase of striatal dopamine in I group rats during acute cerebral ischemia. A 3-week voluntary wheel running significantly enhances the striatal dopamine before ischemia and obstructs a further increase of dopamine during acute cerebral ischemia in 3RI group rats. At 24 hours after ischemia, striatal dopamine returned to pre-ischemic levels in 3RI group. Striatal dopamine in I group were less than pre-ischemic levels at 7 days. Behavioral data indicated that 3-week voluntary wheel running promoted recovery of anxiety-like behavior and gait were not affected by 2-VO cerebral ischemia at 24 hours post-ischemia rats. Therefore, it can be concluded that 3-week physical exercise significantly increased the striatal dopamine and improved anxiety-like behavior by inhibiting the increase of dopamine during acute cerebral ischemia and suppressing the decrease of dopamine after 24 hours and 7 days cerebral ischemia.

Adiponectin-Transfected Endothelial Progenitor Cells Have Protective Effects After 2-Hour Middle-Cerebral Artery Occlusion in Rats With Type 2 Diabetes Mellitus

Objectives: This present study aimed to examine the effects of adiponectin-transfected endothelial progenitor cells (LV-APN-EPCs) on cerebral ischemia–reperfusion injury in rats with type 2 diabetes mellitus (T2DM) and to explore the underlying mechanisms.

Methods: Seventy male Sprague–Dawley rats with T2DM were randomly divided into sham, phosphate-buffered saline (PBS), LV-APN-EPCs, LV-EPCs, and EPCs groups. Transient middle cerebral artery occlusion (MCAO) was induced by the intraluminal suture method. After 1 h of reperfusion, the five interventions were performed by tail-vein injections. The modified neurological severity score (mNSS) was used to assess neurological function before and on days 1, 7, and 14 after MCAO. After 14 days, magnetic resonance imaging scanning, hematoxylin and eosin staining, terminal dUTP nick-end labeling staining, Western blotting analysis, cluster of differentiation (CD) 31 immunofluorescence, and enzyme-linked immunosorbent assay were used to evaluate infarct rate, morphological damage, cell apoptosis, and microvessel density.

Results: Compared with PBS, LV-EPCs, and EPCs groups, the LV-APN-EPCs group showed significantly lower mNSS score, lower infarct rate, and less morphological damage (all P < 0.05). In addition, compared with other groups, the LV-APN-EPCs group had significantly increased levels of B cell lymphoma/leukemia-2 (Bcl-2) protein, CD31+ microvessels, endothelial nitric oxide synthase, and vascular endothelial growth factor, and decreased levels of Bcl-2-associated X protein and neuronal apoptosis in the peri-infarct cortex (all P < 0.05).

Conclusion: These results suggest that LV-APN-EPCs exert protective effects against cerebral ischemia–reperfusion injury in T2DM rats by increasing angiogenesis.

Kynurenine pathway is altered in BDNF Val66Met knock-in mice: Effect of physical exercise

The Brain-Derived Neurotrophic Factor (BDNF) Val66Met polymorphism has been correlated with increased predisposition to develop cognitive and psychiatric disorders, and with a reduced response to some therapeutic treatments. However, the mechanisms underlying these impairments are currently not completely understood. Remarkably, kynurenine pathway alterations have also been implicated in cognitive and psychiatric disorders. Moreover, recent evidence suggests that physical exercise may promote beneficial effects by controlling kynurenine metabolism in the muscle. The aim of the present study was to assess whether the kynurenine pathway was differentially regulated in sedentary and exercising wild-type (BDNF^Val/Val) and homozygous knock-in BDNF Val66Met (BDNF^Met/Met) mice. We found that plasma and hippocampal levels of kynurenic acid and the hippocampal mRNA levels of IDO1 and KAT2 protein levels were increased in BDNF^Met/Met mice and were not modulated by physical exercise. On the contrary, KAT1 protein levels in the gastrocnemius muscle were reduced, whereas MCP1 mRNA in the gastrocnemius muscle and GFAP protein in the hippocampus were increased in BDNF^Met/Met mice compared to BDNF^Val/Val mice, and reduced by physical exercise. Physical exercise increased plasmatic kynurenine levels only in BDNF^Met/Met mice, and protein levels of KAT1 and KAT4 in the gastrocnemius muscle and hippocampus respectively, regardless of the genotype. Finally, we found that physical exercise was able to enhance the hippocampal-dependent memory only in the BDNF^Val/Val mice. Overall our results showing an overactivation of the kynurenine pathway in the BDNF^Met/Met mice may suggest a possible mechanism underlying the cognitive deficits reported in the BDNF Val66Met carriers.

Knockdown of FAM83D Enhances Radiosensitivity in Coordination with Irradiation by Inhibiting EMT via the Akt/GSK-3β/Snail Signaling Pathway in Human Esophageal Cancer Cells

Purpose

To explore the effects of FAM83D on the proliferation, invasion and radiosensitivity of human esophageal cancer cells and to elucidate the mechanism involved in the regulation of the growth and metastasis of esophageal cancer cells.

Methods and Materials

This study included sixty-nine patients with esophageal cancer. The expression levels of FAM83D in the esophageal cancer tissues and paracarcinoma tissues of the sixty-nine patients were measured. We also examined FAM83D expression in five cell lines. We analyzed the effects of FAM83D on the proliferation, invasion and radiosensitivity of human esophageal cancer cells via MTS, Transwell, and colony formation assays. The effect of FAM83D knockdown on cell apoptosis was assayed by flow cytometry. In addition, we also examined changes in the expression of metastasis-related molecules at the protein and mRNA levels by qRT-PCR and Western blotting after silencing FAM83D expression, and we detected the expression of PI3K/Akt signaling-related proteins by Western blotting.

Results

The results demonstrated that the expression of FAM83D was obviously higher in esophageal cancer tissues and cell lines than that in human adjacent normal tissues and normal esophageal epithelial cell lines. FAM83D overexpression was positively associated with tumor size, tumor-node-metastasis (TNM) stage, T classification, N classification, distant metastasis and relapse and was negatively associated with patient survival rates. FAM83D shRNA transfection suppressed its expression. Compared to that in the control group, the proliferation of tumor cells in the FAM83D shRNA group was hindered after exposure to radiation in vitro and in vivo; in addition, FAM83D knockdown inhibited cell invasion, induced apoptosis and regulated apoptosis-related protein expression. Moreover, the radiosensitivity of esophageal cancer cells was increased after depletion of FAM83D. In addition, FAM83D silencing was associated with the reversion of EMT, as reflected by an increase in the epithelial marker E-cadherin and a decrease in the mesenchymal markers N-cadherin and vimentin. Further study showed that FAM83D depletion suppressed the signaling pathway involving p-Akt, p-GSK-3β and Snail.

Conclusion

The results reveal that FAM83D may be a potential therapeutic target for esophageal squamous cell carcinoma (ESCC) and that lower expression of FAM83D in coordination with irradiation promotes the radiosensitization of ESCC by inducing EMT through the Akt/GSK-3β/Snail signaling pathway.

Angelica sinensis extract protects against ischemia-reperfusion injury in the hippocampus by activating p38 MAPK-mediated p90RSK/p-Bad and p90RSK/CREB/BDNF signaling after transient global cerebral ischemia in rats

ETHNOPHARMACOLOGICAL RELEVANCE

Angelica sinensis (Oliv.) Diels, commonly known as Dang Gui (DG), is one of the most popular traditional Chinese herbal medicines for the treatment of stroke. However, the effects of DG on transient global cerebral ischemia (GCI) and its precise mechanisms remain unclear.

AIM OF THE STUDY

This study aimed to investigate the effects of the DG extract on ischemia-reperfusion (I/R) injury in the hippocampus 7 d after transient GCI and to identify the potential mitogen-activated protein kinase (MAPK)-related signaling pathway in the hippocampus involved in the effects.

MATERIALS AND METHODS

Rats were intragastrically administered DG at doses of 0.25 g/kg (DG-0.25g), 0.5 g/kg (DG-0.5g), or 1 g/kg (DG-1g) 1, 3, and 5 d after GCI.

RESULTS

DG-0.5g and DG-1g treatments effectively promoted hippocampal cornu ammonis 1 (CA1) neuronal survival. DG-0.5g and DG-1g treatments markedly increased phospho-p38 MAPK (p-p38 MAPK), phospho-90-kDa ribosomal S6 kinase (p-p90RSK), cytosolic and mitochondrial phospho-Bad (p-Bad), phospho-cAMP response element-binding protein (p-CREB), brain-derived neurotrophic factor (BDNF), and p-CREB/BDNF expression; decreased 4-hydroxy-2-nonenal, cytochrome c (Cytc), and cleaved caspase-3 expression, and inhibited apoptosis in the hippocampal CA1 region. Pretreatment with a specific inhibitor of p38 MAPK, SB203580, completely blocked the effects of DG-1g on the expression of the aforementioned proteins.

CONCLUSIONS

DG-0.5g and DG-1g treatments exerted neuroprotective effects on I/R injury by activating p38 MAPK-mediated p90RSK/p-Bad-induced anti-apoptotic-Cytc/caspase-3-related and p90RSK/CREB/BDNF survival signaling in the hippocampus 7 d after transient GCI.

Modulation of Cognition: The Role of Gnidia glauca on Spatial Learning and Memory Retention in High-Fat Diet-Induced Obese Rats

Chronic exposures to high-fat diets are linked to neuropathological changes that culminate in obesity-related cognitive dysfunction and brain alteration. Learning, memory performance, and executive function are the main domains affected by an obesogenic diet. There are limited effective therapies for addressing cognitive deficits. Thus, it is important to identify additional and alternative therapies. In African traditional medicine, Gnidia glauca has putative efficacy in the management of obesity and associated complications. The use of Gnidia glauca is largely based on its long-term traditional use. Its therapeutic application has not been accompanied by sufficient scientific evaluation to validate its use. Therefore, the current study sought to explore the modulatory effects of dichloromethane leaf extracts of Gnidia glauca on cognitive function in the high-fat diet- (HFD-) induced obese rats. Obesity was induced by feeding the rats with prepared HFD and water ad libitum for 6 weeks. The in vivo antiobesity effects were determined by oral administration of G. glauca at dosage levels of 200, 250, and 300 mg/kg body weight in HFD-induced obese rats from the 6th to the 12th weeks. The Lee obesity index was used as a diagnostic criterion of obesity. The Morris water maze was employed to test spatial learning and memory retention in rats. The results indicated that Gnidia glauca showed potent antiobesity effects as indicated in the reduction of body weight and obesity index in extract-treated rats. Moreover, Gnidia glauca exhibited cognitive-enhancing effects in obese rats. The positive influences on cognitive functions might be attributed to the extracts' phytochemicals that have been suggested to confer protection against obesity-induced oxidative damage, reduction of central inflammation, and increased neurogenesis. The therapeutic effects observed suggest that Gnidia glauca might be an alternative to current medications for the symptomatic complications of obesity, such as learning and memory loss. Further studies are therefore needed to establish its toxicity profiles.

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.

Bone Marrow Stromal Cells With Exercise and Thyroid Hormone Effect on Post-Stroke Injuries in Middle-aged Mice

Introduction:

Based on our previous findings, the treatment of stem cells alone or in combination with thyroid hormone (T₃) and mild exercise could effectively reduce the risk of stroke damage in young mice. However, it is unclear whether this treatment is effective in aged or middle-aged mice. Therefore, this study designed to assess whether combination of Bone Marrow Stromal Cells (BMSCs) with T₃ and mild treadmill exercise can decrease stroke complications in middle-aged mice.

Methods:

Under laser Doppler flowmetry monitoring, transient focal cerebral ischemia was produced by right Middle Cerebral Artery Occlusion (MCAO) for 45 min followed by 7 days of reperfusion in middle-aged mice. BMSCs (1×10⁵) were injected into the right cerebral ventricle 24 h after MCAO, followed by daily injection of triiodothyronine (T₃) (20 μg/100 g/d SC) and 6 days of running on a treadmill. Infarct size, neurological function, apoptotic cells and expression levels of Glial Fibrillary Acidic Protein (GFAP) were evaluated 1 week after stroke.

Results:

Post-ischemic treatment with BMSCs or with T₃ and or mild treadmill exercise alone or in combination did not significantly change neurological function, infarct size, and apoptotic cells 7 days after ischemia in middle-aged mice (P>0.05). However, the expression of GFAP significantly reduced after treatment with BMSCs and or T₃ (P<0.01).

Conclusion:

Our findings indicate that post-stroke treatment BMSCs with exercise and thyroid hormone cannot reverse neuronal damage 7 days after ischemia in middle-aged mice. These findings further support that age is an important variable in stroke treatment

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.

Astragaloside VI Promotes Neural Stem Cell Proliferation and Enhances Neurological Function Recovery in Transient Cerebral Ischemic Injury via Activating EGFR/MAPK Signaling Cascades

Radix Astragali (AR) is a commonly used medicinal herb for post-stroke disability in Traditional Chinese Medicine but its active compounds for promoting neurogenic effects are largely unknown. In the present study, we tested the hypothesis that Astragaloside VI could be a promising active compound from AR for adult neurogenesis and brain repair via targeting epidermal growth factor (EGF)-mediated MAPK signaling pathway in post-stroke treatment. By using cultured neural stem cells (NSCs) and experimental stroke rat model, we investigated the effects of Astragaloside VI on inducing NSCs proliferation and self-renewal in vitro, and enhancing neurogenesis for the recovery of the neurological functions in post-ischemic brains in vivo. For animal experiments, rats were undergone 1.5 h middle cerebral artery occlusion (MCAO) plus 7 days reperfusion. Astragaloside VI (2 μg/kg) was daily administrated by intravenous injection (i.v.) for 7 days. Astragaloside VI treatment promoted neurogenesis and astrogenic formation in dentate gyrus zone, subventricular zone, and cortex of the transient ischemic rat brains in vivo. Astragaloside VI treatment enhanced NSCs self-renewal and proliferation in the cultured NSCs in vitro without affecting NSCs differentiation. Western blot analysis showed that Astragaloside VI up-regulated the expression of nestin, p-EGFR and p-MAPK, and increased neurosphere sizes, whose effects were abolished by the co-treatment of EGF receptor inhibitor gefitinib and ERK inhibitor PD98059. Behavior tests revealed that Astragaloside VI promoted the spatial learning and memory and improved the impaired motor function in transient cerebral ischemic rats. Taken together, Astragaloside VI could effectively activate EGFR/MAPK signaling cascades, promote NSCs proliferation and neurogenesis in transient cerebral ischemic brains, and improve the repair of neurological functions in post-ischemic stroke rats. Astragaloside VI could be a new therapeutic drug candidate for post-stroke treatment.

Modulation of long-term potentiation-like cortical plasticity in the healthy brain with low frequency-pulsed electromagnetic fields

Background

Non-depolarizing magnetic fields, like low frequency-pulsed electromagnetic fields (LF-PEMFs) have shown the ability to modulate living structures, principally by influencing synaptic activity and ion channels on cellular membranes. Recently, the CTU Mega 20 device was presented as a molecular accelerator, using energy up to 200 J and providing high-power (2 Tesla) pulsating fields with a water-repulsive (diamagnetic) action and tissue biostimulation. We tested the hypothesis that LF-PEMFs could modulate long-term corticospinal excitability in healthy brains by applying CTU Mega 20^®. Ten healthy subjects without known neurological and/or psychiatric diseases entered the study. A randomized double-blind sham-controlled crossover design was employed, recording TMS parameters (amplitude variation of the motor evoked potential as index of cortical excitability perturbations of the motor system) before (pre) and after (post + 0, + 15, + 30 min) a single CTU Mega 20 session on the corresponding primary right-hand motor area, using a real (magnetic field = 2 Tesla; intensity = 90 J; impulse frequency = 7 Hz; duration = 15 min) or sham device. A two-way repeated measures ANOVA with TIME (pre, post + 0, + 15, + 30 min) and TREATMENT (real vs. sham stimulation) as within-subjects factor was applied.

Results

A significant TIME × TREATMENT interaction was found (p < 0.001). Post hoc comparisons showed a significant effect of TIME, with significant differences at + 0, + 15 and + 30 min compared to baseline after real stimulation (all p < 0.05) but not after sham stimulation (all p < 0.05) and significant effects of TREATMENT, with significant differences at + 0, + 15 and + 30 min for real stimulation compared to sham stimulation (all p < 0.005). No significant depolarizing effects were detected throughout the (real) stimulation.

Conclusions

Our proof-of-concept study in healthy subjects supports the idea that non-ionizing LF-PEMFs induced by the CTU Mega 20 diamagnetic acceleration system could represent a new approach for brain neuromodulation. Further studies to optimize protocol parameters for different neurological and psychiatric conditions are warranted.

Trial Registration The present work has been retrospectively registered as clinical trial on ClinicalTrials.gov NCT03537469 and publicly released on May 24, 2018

Electronic supplementary material

The online version of this article (10.1186/s12868-018-0434-z) contains supplementary material, which is available to authorized users.

Effect of treadmill exercise on spatial navigation impairment associated with cerebellar Purkinje cell loss following chronic cerebral hypoperfusion

In addition to roles in motor coordination, the cerebellum is also associated with cognitive function. The aim of the present study was to investigate the effect of treadmill exercise on spatial navigation deficit induced by chronic cerebral hypoperfusion (CCH). Furthermore, whether decreased loss of Purkinje cells, which contain the calcium-binding protein in the posterior lobe of the cerebellum, attenuates the spatial navigation deficit induced by CCH was also investigated. Wistar rats were randomly divided into three groups: Sham group, bilateral common carotid arteries occlusion (BCCAO) group and a BCCAO + exercise (Ex) group. The rats in the BCCAO + Ex group ran on a treadmill for 30 min once a day for 8 weeks, starting at 4 weeks post-birth. CCH was induced by performing BCCAO at 12 weeks post-birth. The Morris water maze test was performed to determine the spatial navigation function of the rats. To investigate the histological features of the cerebellum in all of the experimental groups post-treatment, terminal deoxynucleotidyl transferase dUTP nick end labeling staining, as well as immunohistochemical analysis revealing the expression of calbindin, parvalbumin, glial fibrillary acidic protein, ionized calcium-binding adaptor molecule 1 and caspase-3, was performed. The results of the present study revealed that treadmill exercise improved spatial navigation, decreased the expression of reactive astrocytes and microglial cells, and decreased apoptotic rates in the cerebellar vermis post-CCH. Treadmill exercise also attenuated the loss of Purkinje cells following CCH. The number of Purkinje cells was revealed to be negatively correlated with spatial navigation performance. These results indicate that treadmill exercise may attenuate spatial navigation impairment via inhibition of Purkinje cell loss in the posterior lobe of the cerebellum following CCH. Therefore, treadmill exercise may represent a therapeutic strategy for the treatment of patients with spatial navigation impairment following CCH.

Physical Exercise Promotes Novel Object Recognition Memory in Spontaneously Hypertensive Rats after Ischemic Stroke by Promoting Neural Plasticity in the Entorhinal Cortex

Cerebral ischemia leads to memory impairment, and several studies have indicated that physical exercise (PE) has memory-improving effects after ischemia. This study was designed to further explore the specific role of PE in novel object recognition (NOR) memory after stroke and the exact cortical regions in which memory is restored by PE. Spontaneously hypertensive rats (SHR) were subjected to transient middle cerebral artery occlusion (tMCAO) or sham surgery, followed by 26 days of PE starting on day 3 post-tMCAO. Thereafter, infarct volume, neurobehavioral outcome and NOR memory were assessed. Immunofluorescence staining and Luxol Fast Blue (LFB) staining were performed in the prefrontal cortex, entorhinal cortex and corpus callosum regions. Western blot analysis was performed to detect expressions of Nestin, Bcl-2 and SYN proteins in the entorhinal cortex. After tMCAO, NOR memory impairment was found in SHR. Rats subjected to PE post-tMCAO showed increased discrimination ratio, as well as significant decreases in infarct volumes and modified neurological severity scores (mNSS), when compared with tMCAO rats without PE. After stroke, NeuN-positive cell number was drastically reduced in the entorhinal cortex, rather than in the prefrontal cortex. Ischemic stroke had no impact on myelin and phospholipids, and the ratio of SMI-32/MBP in the corpus callosum. PE increased NeuN, Nestin, Ki67, MBP, SYN, PSD-95 and Bcl-2 expressions in the entorhinal cortex, while TUNEL and SMI-32 expressions were decreased. In conclusion, the NOR memory-improving capacity promoted by PE was closely related to neuronal cell proliferation and synaptic plasticity of the entorhinal cortex.

Tai Chi Chuan and Baduanjin Mind-Body Training Changes Resting-State Low-Frequency Fluctuations in the Frontal Lobe of Older Adults: A Resting-State fMRI Study

Age-related cognitive decline is a significant public health concern. Recently, non-pharmacological methods, such as physical activity and mental training practices, have emerged as promising low-cost methods to slow the progression of age-related memory decline. In this study, we investigated if Tai Chi Chuan (TCC) and Baduanjin modulated the fractional amplitude of low-frequency fluctuations (fALFF) in different frequency bands (low-frequency: 0.01-0.08 Hz; slow-5: 0.01-0.027 Hz; slow-4: 0.027-0.073 Hz) and improved memory function. Older adults were recruited for the randomized study. Participants in the TCC and Baduanjin groups received 12 weeks of training (1 h/day for 5 days/week). Participants in the control group received basic health education. Each subject participated in memory tests and fMRI scans at the beginning and end of the experiment. We found that compared to the control group: (1) TCC and Baduanjin groups demonstrated significant improvements in memory function; (2) TCC increased fALFF in the dorsolateral prefrontal cortex (DLPFC) in the slow-5 and low-frequency bands; and (3) Baduanjin increased fALFF in the medial PFC in the slow-5 and low-frequency bands. This increase was positively associated with memory function improvement in the slow-5 and low-frequency bands across the TCC and Baduanjin groups. Our results suggest that TCC and Baduanjin may work through different brain mechanisms to prevent memory decline due to aging.

Effects of the combined treatment of bone marrow stromal cells with mild exercise and thyroid hormone on brain damage and apoptosis in a mouse focal cerebral ischemia model

This study examined whether post-stroke bone marrow stromal cells (BMSCs) therapy combined with exercise (EX) and/or thyroid hormone (TH) could reduce brain damage in an experimental ischemic stroke in mice. Focal cerebral ischemia was induced under Laser Doppler Flowmetry (LDF) guide by 45 min of middle cerebral artery occlusion (MCAO), followed by 7 days of reperfusion in albino mice. BMSCs were injected into the right cerebral ventricle 24 h after MCAO, followed by daily injection of T3 (20 μg/100 g weight S.C) and 6 days of running on a treadmill. Infarct size, neurobehavioral test, TUNEL and BrdU positive cells were evaluated at 7 days after MCAO. Treatment with BMSCs and mild EX alone significantly reduced the infarct volume by 23% and 44%, respectively (both, p < 0.001). The BMSCs + TH, BMSCs + EX, and BMSCs + EX + TH combination therapies significantly reduced the infarct volume by 26%, 51%, and 70%, respectively (all, p < 0.001). A significant improvement in the neurobehavioral functioning was observed in the EX, BMSCs + EX, and BMSCs + EX+ TH groups (p < 0.001). The number of TUNEL-positive cells (a marker of apoptosis) was significantly reduced in the EX, BMSCs, BMSCs + EX, BMSCs + TH, and BMSCs + EX + TH groups (all, p < 0.001). Moreover, the combination therapy considerably increased BrdU-labeled cells in the subventricular zone (SVZ) (p < 0.01). Our findings indicated that the combined treatment of BMSCs with mild EX and TH more efficiently reduces the cerebral infarct size after stroke. More likely, these effects mediate via enchaining generation of new neuronal cells and the attenuation of apoptosis in ischemia stroke in young mice.

Treatment with Enriched Environment Reduces Neuronal Apoptosis in the Periinfarct Cortex after Cerebral Ischemia/Reperfusion Injury

Background/Aims: Enriched environment (EE) has been reported to exert neuroprotective effect in animal models of ischemic stroke. However, the underlying mechanism remains unclear. The purpose of this study was to investigate the effect of EE treatment on neuronal apoptosis in the periinfarct cortex after cerebral ischemia/reperfusion (I/R) injury. Methods: The cerebral I/R injury was established by middle cerebral artery occlusion (MCAO). A set of behavioral tests including the modified neurological severity score (mNSS), limb-placing test and foot-fault test were conducted. The infarct volume and the neuronal survival rate were evaluated by Nissl staining. The morphology and ultrastructure of ischemic neurons was examined by transmission electron microscopy. Neuronal apoptosis was assessed by double labeling of TdT-mediated dUTP-biotin nick end labeling (TUNEL) with NeuN. The expressions of apoptosis-related proteins were tested by western blotting and immunohistochemical labeling. Results: EE treatment improved neurological function, reduced infarct volume, increased neuronal survival rate and alleviated the morphological and ultrastructural damage of neurons (especially mitochondria) after I/R injury. EE treatment reduced the neuronal apoptosis, increased B cell lymphoma/leukemia-2 (Bcl-2) protein levels while decreased Bcl-2-associated X protein (Bax), cytochrome c, caspase-3 expressions and Bax/Bcl-2 ratio in the periinfarct cortex after cerebral I/R injury. Conclusion: Our findings suggest that EE treatment inhibits neuronal apoptosis in the periinfarct cortex after focal cerebral I/R injury, which may be one of the possible mechanisms underlying the neuroprotective effects of EE.

Comparison of the behavioral effects of exercise and high fat diet on cognitive function in adolescent rats

Adolescence is a critical period for neurodevelopment, neuronal plasticity, and cognitive function. Experiences of adolescence can be exerted positive and negative effects on brain development. Physical exercise has a positive effect on brain function, which is characterized by improving memory function and increased neural plasticity. High fat diet (HFD)-induced obesity has a negative effect on brain function, which is characterized by insulin resistance and neuroinflammation and reduced microvessel constructure. Although the positive effect of exercise and negative effect of obesity on cognitive function have been documented, it has not been well whether comparison of the effects of exercise and obesity on cognitive function in adolescent rats. In the present study, we evaluated the behavioral changes related to cognitive function induced by exercise and obesity in adolescent rats. Male Wistar rats were randomly divided into three groups: the control group (CON), the exercise group (Ex), the high fat diet group (HFD). The HFD containing fat 60% was freely provided. The present results showed that spatial learning ability and short-term memory did not show significant effect exercise as compared to the control group. The present results showed that spatial learning ability and short-term memory was significantly decreased HFD-induced obesity group as compared to the control group. These results suggest that positive effect of physical exercise in adolescence rats may be exerted no significant effect on cognitive function. But, negative effect of HFD-induced obesity might induce cognitive impairment. HFD-induced obesity in adolescent rats may be used as an animal model of neurodevelopmental disorders.

The ameliorative effects of exercise on cognitive impairment and white matter injury from blood-brain barrier disruption induced by chronic cerebral hypoperfusion in adolescent rats

Vascular dementia is the progressive change in blood vessels that leads to neuronal injuries in vulnerable areas induced by chronic cerebral hypoperfusion (CCH). CCH induces disruption of blood-brain barrier (BBB), and this BBB disruption can initiate the cognitive impairment and white matter injury. In the present study, we evaluated the effect of treadmill exercise on the cognitive impairment, white matter injury, and BBB disruption induced by CCH. Vascular dementia was induced by permanent bilateral common carotid arteries occlusion (BCCAO) in rats. The rats in the exercise group were made to run on a treadmill for 30min once a day for 14 weeks, starting 4 weeks after birth. Our results revealed that treadmill exercise group was alleviated the cognitive impairment and myelin degradation induced by CCH. The disruption of BBB after CCH indicates degradation of occludin, zonula occluden-1 (ZO-1), and up-regulation of matrix metalloproteinases (MMPs). Treadmill exercise may provide protective effects on BBB disruption from degradation of occludin, ZO-1, and overexpression of MMP-9 after CCH. These findings suggest that treadmill exercise ameliorates cognitive impairment and white matter injury from BBB disruption induced by CCH in rats. The present study will be valuable for means of prophylactic and therapeutic intervention for patients with CCH.

Treadmill Exercise Improves Memory Function Depending on Circadian Rhythm Changes in Mice

Purpose

Exercise enhances memory function by increasing neurogenesis in the hippocampus, and circadian rhythms modulate synaptic plasticity in the hippocampus. The circadian rhythm-dependent effects of treadmill exercise on memory function in relation with neurogenesis were investigated using mice.

Methods

The step-down avoidance test was used to evaluate short-term memory, the 8-arm maze test was used to test spatial learning ability, and 5-bromo-2’-deoxyuridine immunofluorescence was used to assess neurogenesis. Western blotting was also performed to assess levels of synaptic plasticity-associated proteins, such as brain-derived neurotrophic factor, tyrosine kinase receptor B, phosphorylated cAMP response element-binding protein, early growth response protein 1, postsynaptic density protein 95, and growth-associated protein 43. The mice in the treadmill exercise at zeitgeber 1 group started exercising 1 hour after sunrise, the mice in the treadmill exercise at zeitgeber 6 group started exercising 6 hours after sunrise, and the mice in the treadmill exercise at zeitgeber 13 group started exercising 1 hour after sunset. The mice in the exercise groups were forced to run on a motorized treadmill for 30 minutes once a day for 7 weeks.

Results

Treadmill exercise improved short-term memory and spatial learning ability, and increased hippocampal neurogenesis and the expression of synaptic plasticity-associated proteins. These effects of treadmill exercise were stronger in mice that exercised during the day or in the evening than in mice that exercised at dawn.

Conclusions

Treadmill exercise improved memory function by increasing neurogenesis and the expression of synaptic plasticity-associated proteins. These results suggest that the memory-enhancing effect of treadmill exercise may depend on circadian rhythm changes.

Neuroprotective Effect of Low Frequency-Pulsed Electromagnetic Fields in Ischemic Stroke

Low frequency-pulsed electromagnetic fields (LF-PEMFs) affect many biological processes; however, the fundamental mechanisms responsible for these effects remain unclear. Our study aimed to investigate the effect of LF-PEMFs on neuroprotection after ischemic stroke. C57B6 mice were exposed to LF-PEMF (F = 60 Hz, Bm = 10 mT) after photothrombotic occlusion. We measured the BDNF/TrkB/Akt signaling pathway, pro-apoptotic and pro-survival protein and gene expressions, and the expression of inflammatory mediators and performed behavioral tests in both LF-PEMF-treated and untreated ischemic stroke mice. Our results showed that LF-PEMF treatment promotes activation of the BDNF/TrkB/Akt signaling pathway. Subsequently, pro-survival proteins were significantly increased, while pro-apoptotic proteins and inflammatory mediators were decreased in ischemic stroke mice after LF-PEMF treatment. The results demonstrated that LF-PEMF exposure has a neuroprotective effect after ischemic stroke in mice during the recovery process.

Pentoxifylline Alleviates Perinatal Hypoxic-Ischemia-Induced Short-term Memory Impairment by Suppressing Apoptosis in the Hippocampus of Rat Pups

Purpose:

Perinatal hypoxic-ischemic brain damage is a major cause of acute mortality and chronic neurologic morbidity in infants and children. We investigated the effects of pentoxifylline, a methylxanthine derivative and type-4 phosphodiesterase inhibitor, on short-term memory and apoptotic neuronal cell death in the hippocampus following perinatal hypoxic-ischemia in newborn rats.

Methods:

We used a step-down avoidance task to evaluate short-term memory and 3ʹ-5ʹ-cyclic adenosine monophosphate (cAMP) assay to detect cAMP levels. We evaluated apoptosis using a terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling (TUNEL) assay for evidence of DNA fragmentation, immunohistochemistry for caspase-3 levels, and western blot for Bcl-2 and Bax.

Results:

Perinatal hypoxic-ischemic injury increased apoptotic cell death in the hippocampus, resulting in impaired short-term memory with decreased cAMP levels. Pentoxifylline treatment improved short-term memory by suppressing apoptotic cell death in the hippocampus with elevated cAMP levels.

Conclusions:

Pentoxifylline ameliorated perinatal hypoxic-ischemia in rat pups. This alleviating effect could be ascribed to the inhibition apoptosis due to increased cAMP production by pentoxifylline.

Exercise and Environmental Enrichment as Enablers of Task-Specific Neuroplasticity and Stroke Recovery

Improved stroke care has resulted in greater survival, but >50% of patients have chronic disabilities and 33% are institutionalized. While stroke rehabilitation is helpful, recovery is limited and the most significant gains occur in the first 2-3 months. Stroke triggers an early wave of gene and protein changes, many of which are potentially beneficial for recovery. It is likely that these molecular changes are what subserve spontaneous recovery. Two interventions, aerobic exercise and environmental enrichment, have pleiotropic actions that influence many of the same molecular changes associated with stroke injury and subsequent spontaneous recovery. Enrichment paradigms have been used for decades in adult and neonatal animal models of brain injury and are now being adapted for use in the clinic. Aerobic exercise enhances motor recovery and helps reduce depression after stroke. While exercise attenuates many of the signs associated with normal aging (e.g., hippocampal atrophy), its ability to reverse cognitive impairments subsequent to stroke is less evident. It may be that stroke, like other diseases such as cancer, needs to use multimodal treatments that augment complimentary neurorestorative processes.

Baicalin alleviates ischemia-induced memory impairment by inhibiting the phosphorylation of CaMKII in hippocampus

Baicalin has a significant neuroprotective effect in stroke. However, the mechanism remains unclear. This study was to reveal the mechanisms by which baicalin protected hippocampal neurons and improved learning and memory impairment after global cerebral ischemia/reperfusion in gerbil. In the present study, the Morris water maze test showed that baicalin significantly improved learning and memory impairment after global cerebral ischemia/reperfusion in gerbils. Laser scanning confocal fluorescence microscope examination showed that baicalin suppressed OGD-induced augmentation of intracellular calcium concentration. Western blotting analysis indicated that baicalin suppressed ischemia-caused elevated phosphorylation level of CaMKII in vivo, in hippocampal neurons in culture, and in SH-SY5Y cells in culture. Western blotting, TUNEL and RNA interference technology were applied to detect effects of baicalin on neuronal apoptosis. We found that baicalin, a CaMKII inhibitor and knocking down the CaMKII prevented OGD-induced apoptosis of hippocampal or SH-SY5Y cells in culture. Therefore, these results suggested that baicalin improves learning and memory impairment induced by global cerebral ischemia/reperfusion in gerbils via attenuating the phosphorylation level of CaMKII and further preventing hippocampal neuronal apoptosis.

Neuroprotective effects of atorvastatin against cerebral ischemia/reperfusion injury through the inhibition of endoplasmic reticulum stress

Cerebral ischemia triggers secondary ischemia/reperfusion injury and endoplasmic reticulum stress initiates cell apoptosis. However, the regulatory mechanism of the signaling pathway remains unclear. We hypothesize that the regulatory mechanisms are mediated by the protein kinase-like endoplasmic reticulum kinase/eukaryotic initiation factor 2α in the endoplasmic reticulum stress signaling pathway. To verify this hypothesis, we occluded the middle cerebral artery in rats to establish focal cerebral ischemia/reperfusion model. Results showed that the expression levels of protein kinase-like endoplasmic reticulum kinase and caspase-3, as well as the phosphorylation of eukaryotic initiation factor 2α, were increased after ischemia/reperfusion. Administration of atorvastatin decreased the expression of protein kinase-like endoplasmic reticulum kinase, caspase-3 and phosphorylated eukaryotic initiation factor 2α, reduced the infarct volume and improved ultrastructure in the rat brain. After salubrinal, the specific inhibitor of phosphorylated eukaryotic initiation factor 2α was given into the rats intragastrically, the expression levels of caspase-3 and phosphorylated eukaryotic initiation factor 2α in the were decreased, a reduction of the infarct volume and less ultrastructural damage were observed than the untreated, ischemic brain. However, salubrinal had no impact on the expression of protein kinase-like endoplasmic reticulum kinase. Experimental findings indicate that atorvastatin inhibits endoplasmic reticulum stress and exerts neuroprotective effects. The underlying mechanisms of attenuating ischemia/reperfusion injury are associated with the protein kinase-like endoplasmic reticulum kinase/eukaryotic initiation factor 2α/caspase-3 pathway.

Pre-ischemic exercise reduces apoptosis in hippocampal CA3 cells after cerebral ischemia by modulation of the Bax/Bcl-2 proteins ratio and prevention of caspase-3 activation

Ischemia induces physiological alterations in neurons that lead to cell death. This study investigated the effects of pre-ischemic exercise on CA3 neurons. Rats were divided into three groups. Animals in the exercise group were trained 5 days a week for 4 weeks. Ischemia was induced by occlusion of both common carotid arteries (CCAs) for 20 min. Apoptotic cell death was detected by TUNEL assay. Furthermore, expression of different proteins was determined by immunohistochemical staining. The number of TUNEL-positive cells was significantly increased in the ischemia group, but pre-ischemic exercise significantly reduced apoptotic cell death (P < 0.001). In addition, our results showed a significant increase in the Bax/Bcl-2 ratio in the ischemia group. Pre-ischemic exercise attenuated this ratio (P < 0.05). Furthermore, the number of active caspase-3-positive neurons was significantly increased in the ischemia group, which was reduced markedly by exercise preconditioning (P < 0.05). This study showed that pre-ischemic exercise can exert neuroprotective effects against ischemia in CA3 neurons.

Stress-Induced Depression Is Alleviated by Aerobic Exercise Through Up-Regulation of 5-Hydroxytryptamine 1A Receptors in Rats

PURPOSE

Stress is associated with depression, which induces many psychiatric disorders. Serotonin, also known as 5-hydroxy-tryptamine (5-HT), acts as a biochemical messenger and regulator in the brain. It also mediates several important physiological functions. Depression is closely associated with an overactive bladder. In the present study, we investigated the effect of treadmill exercise on stress-induced depression while focusing on the expression of 5-HT 1A (5-H1A) receptors in the dorsal raphe.

METHODS

Stress was induced by applying a 0.2-mA electric foot shock to rats. Each set of electric foot shocks comprised a 6-second shock duration that was repeated 10 times with a 30-second interval. Three sets of electric foot shocks were applied each day for 7 days. For the confirmation of depressive state, a forced swimming test was performed. To visualize the expression of 5-HT and tryptophan hydroxylase (TPH), immunohistochemistry for 5-HT and TPH in the dorsal raphe was performed. Expression of 5-H1A receptors was determined by western blot analysis.

RESULTS

A depressive state was induced by stress, and treadmill exercise alleviated the depression symptoms in the stress-induced rats. Expressions of 5-HT, TPH, and HT 1A in the dorsal raphe were reduced by the induction of stress. Treadmill exercise increased 5-HT, TPH, and HT 1A expressions in the stress-induced rats.

CONCLUSIONS

Treadmill exercise enhanced 5-HT synthesis through the up-regulation of 5-HT1A receptors, and improved the stress-induced depression. In the present study, treadmill exercise improved depression symptoms by enhancing 5-HT1A receptor expression. The present results suggest that treadmill exercise might be helpful for the alleviation of overactive bladder and improve sexual function.

Treadmill exercise improves short-term memory by enhancing hippocampal cell proliferation in quinolinic acid-induced Huntington's disease rats

Huntington’s disease (HD) is an inherited genetic disorder, characterized by cognitive dysfunction and abnormal body movements called chorea. Quinolinic acid (QA) is an endogenous metabolite of tryptophan in the kynurenine pathway. QA-induced alterations are similar to the symptoms of HD patients. Physical exercise has beneficial effects on the brain functions. Exercise increases production of neurotrophic factors in the brain and improves learning ability and memory function. In the present study, we investigated the effects of treadmill exercise short-term memory on QA-induced HD rats in relation with cell proliferation. For the induction of Huntington’s animal model, 2 μL of 100 nmol QA was intrastriatal injected into the rats. The rats in the treadmill exercise groups were forced to run on a treadmill for 30 min once a day, five times a week for 2 weeks. Step-down avoidance test was conducted for the determination of short-term memory. Cell proliferation in the hippocampal dentate gyrus was determined by 5-bromo-2′-deoxyuridine (BrdU) and doublecortin (DCX) immunohistochemistry. Western blot for brain-derived neurotrophic factor (BDNF) and tyrosine kinase B (TrkB) were performed. In the present results, treadmill exercise alleviated QA-induced short-term memory impairment in HD rats. Treadmill exercise increased cell proliferation in the hippocampal dentate gyrus through enhancing BDNF expression in the HD rats. These results revealed that treadmill exercise is effective for the symptom improvement in the HD patients.