Motor skills training promotes motor functional recovery and induces synaptogenesis in the motor cortex and striatum after intracerebral hemorrhage in rats

Advancing Post-Stroke Depression Research: Insights from Murine Models and Behavioral Analyses

Post-stroke depression (PSD) represents a significant neuropsychiatric complication that affects between 39% and 52% of stroke survivors, leading to impaired recovery, decreased quality of life, and increased mortality. This comprehensive review synthesizes our current knowledge of PSD, encompassing its epidemiology, risk factors, underlying neurochemical mechanisms, and the existing tools for preclinical investigation, including animal models and behavioral analyses. Despite the high prevalence and severe impact of PSD, challenges persist in accurately modeling its complex symptomatology in preclinical settings, underscoring the need for robust and valid animal models to better understand and treat PSD. This review also highlights the multidimensional nature of PSD, where both biological and psychosocial factors interplay to influence its onset and course. Further, we examine the efficacy and limitations of the current animal models in mimicking the human PSD condition, along with behavioral tests used to evaluate depressive-like behaviors in rodents. This review also sets a new precedent by integrating the latest findings across multidisciplinary studies, thereby offering a unique and comprehensive perspective of existing knowledge. Finally, the development of more sophisticated models that closely replicate the clinical features of PSD is crucial in order to advance translational research and facilitate the discovery of future effective therapies.

Acrobatic training prevents motor deficits and neuronal loss in male and female rats following chronic cerebral hypoperfusion

BACKGROUND

Chronic cerebral hypoperfusion in vascular dementia leads to memory and motor deficits; Physical exercise improves these aspects and promotes neuroprotection. Sexual dimorphism may significantly influence both ischemic and exercise outcomes.

AIMS

The aim of this study was to investigate the effects of 2VO (Two-Vessel occlusion) and the acrobatic training on motor function, functional performance, and tissue loss in male and female rats.

METHODS

Male and female rats were randomly divided into 4 groups: sham acrobatic, sham sedentary, 2VO acrobatic and 2VO sedentary. After 45 days of 2VO surgery, the animals received 4 weeks of acrobatic training. At the end, open field, beam balance and horizontal ladder tests were performed. Brain samples were taken for histological and morphological evaluation.

RESULTS

Spontaneous motor activity in the open field was not affected by 2VO, on the other hand, an impairment in forelimb placement was observed after 2VO and acrobatic training prevented errors and improved hindlimb placement. Neuronal loss was found in the motor cortex and striatum after 2VO, especially in females, which was prevented by acrobatic training.

CONCLUSION

Mild motor damage was found in animals after 2VO when refined movement was evaluated, probably associated to neuronal death in the motor cortex and striatum. The acrobatic exercise showed a neuroprotective effect, promoting neuronal survival and attenuating the motor deficit.

MSCs overexpressing GDNF restores brain structure and neurological function in rats with intracerebral hemorrhage

Mesenchymal stem cells (MSCs) have been applied in transplantation to treat intracerebral hemorrhage (ICH) but with limited efficacy. Accumulated evidence has shown that glial cell-derived neurotrophic factor (GDNF) plays a crucial part in neuronal protection and functional recovery of the brain after ICH; however, GDNF has difficulty crossing the blood-brain barrier, which limits its application. In this study, we investigated the influences of MSCs overexpressing GDNF (MSCs/GDNF) on the brain structure as well as gait of rats after ICH and explored the possible mechanisms. We found that cell transplantation could reverse the neurological dysfunction and brain damage caused by ICH to a certain extent, and MSCs/GDNF transplantation was superior to MSCs transplantation. Moreover, Transplantation of MSCs overexpressing GDNF effectively reduced the volume of bleeding foci and increased the level of glucose uptake in rats with ICH, which could be related to improving mitochondrial quality. Furthermore, GDNF produced by transplanted MSCs/GDNF further inhibited neuroinflammation, improved mitochondrial quality and function, promoted angiogenesis and the survival of neurons and oligodendrocytes, and enhanced synaptic plasticity in ICH rats when compared with simple MSC transplantation. Overall, our data indicate that GDNF overexpression heightens the curative effect of MSC implantation in treating rats following ICH.

Motor Rehabilitation Provides Modest Functional Benefits After Intracerebral Hemorrhage: a Systematic Review and Meta-Analysis of Translational Rehabilitation Studies

Few certainties exist regarding the optimal type, timing, or dosage of rehabilitation after stroke. Despite differing injury mechanisms and recovery patterns following ischemic and hemorrhagic stroke, most translational stroke research is conducted after ischemia. As we enter the era of personalized medicine, exploring subtype-specific treatment efficacy is essential to optimizing recovery. Our objective was to characterize common rehabilitation interventions used after in vivo preclinical intracerebral hemorrhage (ICH) and assess the impact of post-ICH rehabilitation (vs. no-rehabilitation) on recovery of motor function. Following PRISMA guidelines, a systematic review (Academic Search Complete, CINAHL, EMBASE, Medline, PubMed Central) identified eligible articles published up to December 2022. Risk of bias (SYRCLE) and study quality (CAMARADES) were evaluated, and random-effects meta-analysis was used to assess treatment efficacy in recovery of forelimb and locomotor functions. Thirty articles met inclusion criteria, and 48 rehabilitation intervention groups were identified. Most used collagenase to model striatal ICH in young, male rodents. Aerobic exercise, enriched rehabilitation, and constraint-induced movement therapy represented ~ 70% of interventions. Study quality was low (median 4/10, range 2-8), and risk of bias was unclear. Rehabilitation provided modest benefits in skilled reaching, spontaneous impaired forelimb use, and locomotor function; however, effects varied substantially by endpoint, treatment type, and study quality. Rehabilitation statistically improves motor function after preclinical ICH, but whether these effects are functionally meaningful is unclear. Incomplete reporting and variable research quality hinder our capacity to analyze and interpret how treatment factors influence rehabilitation efficacy and recovery after ICH.

Electro-nape-acupuncture regulates the differentiation of microglia through PD-1/PD-L1 reducing secondary brain injury in acute phase intracerebral hemorrhage rats

INTRODUCTION

This study aimed to investigate the effect of electro-nape-acupuncture (ENA) on the differentiation of microglia and the secondary brain injury in rats with acute-phase intracerebral hemorrhage (ICH) through the programmed cell death protein-1/ligand-1 (PD-1/PD-L1) pathway.

METHODS

A total of 27 male Sprague-Dawley rats were randomly divided into three groups: sham group, ICH group, and ENA group. The autologous blood infusion intracerebral hemorrhage model was used to study the effects of ENA by administering electroacupuncture at GB20 (Fengchi) and Jiaji (EX-B2) acupoints on 24 h after the modeling, once per day for 3 days. The neurological function damage, hematoma lesion, and inflammatory cell infiltration were measured by the beam walking test and hematoxylin-eosin staining. The expression of PD-1, PD-L1, CD86, CD206, and related cytokines around the hematoma was measured by western blot, quantitative reverse transcription polymerase chain reaction, and immunofluorescence.

RESULTS

The ICH group had significant neurological deficits (p < .001), hematoma lesions, and inflammatory cell infiltration. The levels of CD86 protein, inflammatory factors tumor necrosis factors (TNF)-α, interleukin (IL)-1β, and IL-6 were increased (p < .001), while CD206 protein was reduced (p < .01), and the number of CD86+ /CD11b+ cells was also increased (p < .001) compared to the sham group. However, after ENA intervention, there was a significant reduction in neurological function damage (p < .05), infiltration of inflammatory cells, and the expression levels of CD86+ /CD11b+ cells (p < .05), resulting in the increased expression of PD-1 protein and differentiation of M2 phenotype significantly (p < .001).

CONCLUSION

The study concludes that ENA could reduce neurological function damage, inhibit the expression of pro-inflammatory cytokines, and improve the infiltration of inflammatory cells to improve secondary brain injury in acute-phase intracerebral hemorrhage rats. These effects could be related to the increased expression of PD-1 around the lesion, promoting the differentiation of microglia from M1 to M2 phenotype.

Probucol treatment after traumatic brain injury activates BDNF/TrkB pathway, promotes neuroregeneration and ameliorates functional deficits in mice

BACKGROUND AND PURPOSE

Traumatic brain injury (TBI) is a major cause of mortality and morbidity worldwide, yet pharmacotherapies for TBI are currently lacking. Neuroregeneration is important in brain repair and functional recovery. In this study, probucol, a cholesterol-lowering drug with established safety profiles, was examined for its therapeutic effects and neuroregenerative actions in TBI.

EXPERIMENTAL APPROACH

Male mice were subjected to the controlled cortical impact model of TBI, followed by daily administration of probucol. Neurological and cognitive functions were evaluated. Histological analyses of the neocortex and hippocampus were performed to detect the lesion, dendritic degeneration (microtubule-associated protein 2), synaptic density (synaptophysin), neurogenesis (doublecortin), brain-derived neurotrophic factor (BDNF) and tropomyosin receptor kinase B (TrkB) activation. Involvement of BDNF/TrkB pathway in probucol-mediated effects was examined in primary cultures of cortical neurons.

KEY RESULTS

Probucol reduced brain lesion volume, enhanced the recovery of body symmetry, improved motor function and attenuated memory dysfunction after TBI. Meanwhile, probucol promoted post-injury dendritic growth and synaptogenesis and increased hippocampal proliferating neuronal progenitor cells, along with the formation as well as the survival of newborn neurons. Moreover, probucol enhances BDNF expression and TrkB activation. In vitro, probucol promoted neurite outgrowth, which was inhibited by a selective TrkB antagonist ANA-12.

CONCLUSIONS AND IMPLICATIONS

Probucol enhanced functional restoration and ameliorated cognitive impairment after TBI by promoting post-injury neuronal remodelling and neurogenesis. Increased activation of BDNF/TrkB pathway by probucol, at least in part, contributed to the neuroregenerative effects of probucol. Together, it may be promising to repurpose probucol for TBI.

Association Between Neurological Outcomes and Timing of Physical Therapy Initiation Among Patients Treated for Aneurysmal Subarachnoid Hemorrhage: A Propensity-Adjusted Analysis

BACKGROUND

Aneurysmal subarachnoid hemorrhage (aSAH) is a debilitating neurological disease associated with poor neurological outcomes.

OBJECTIVE

To evaluate the association between timing of physical therapy (PT) initiation and neurological outcomes among patients treated for aSAH.

METHODS

Patients receiving definitive aneurysm treatment at a single quaternary center (January 1, 2014-July 31, 2019) with data available on PT initiation and the number of sessions were analyzed. Patients were compared based on whether PT initiation was delayed (>24 hours after definitive aneurysm treatment) or nondelayed (≤24 hours after treatment). The primary outcome was a poor neurological outcome at last follow-up (modified Rankin Scale [mRS] score >2). A propensity-adjusted score was generated and included as a covariate in a logistic regression analysis.

RESULTS

Among 382 patients, 260 (68%) had delayed and 122 (32%) had nondelayed PT initiation. A significantly greater percentage of patients in the delayed PT group had an mRS score of >2 at last follow-up (42% [n = 110] vs 20% [n = 24]; P < .001). Among 298 patients with a Hunt and Hess (HH) grade <4, the percentage with an mRS score of >2 at last follow-up was significantly higher in the delayed (34% [62/184]) than nondelayed (18% [21/114]) PT group (P = .006). The logistic regression analysis showed that, among patients with an HH grade of <4, delayed PT initiation increased the risk of having an mRS score of >2 at follow-up (odds ratio = 1.90, 95% CI = 1.02-3.62, P = .047).

CONCLUSION

Delayed PT initiation after definitive aneurysm treatment was associated with poor neurological outcomes regardless of patient characteristics, neurological presentation, or aneurysm characteristics.

Tetramethylpyrazine promotes stroke recovery by inducing the restoration of neurovascular unit and transformation of A1/A2 reactive astrocytes

2,3,5,6-Tetramethylpyrazine (TMP) as an active ingredient extracted from a traditional Chinese herbal medicine Ligusticum chuanxiong Hort. has been proved to penetrate blood-brain barrier (BBB) and show neuroprotective effects on cerebral ischemia. However, whether TMP could regulate astrocytic reactivity to facilitate neurovascular restoration in the subacute ischemic stroke needs to be urgently verified. In this research, permanent occlusion of the middle cerebral artery (MCAO) model was conducted and TMP (10, 20, 40 mg/kg) was intraperitoneally administrated to rats once daily for 2 weeks. Neurological function was evaluated by motor deficit score (MDS). Magnetic resonance imaging (MRI) was implemented to analyze tissue injury and cerebral blood flow (CBF). Magnetic resonance angiography (MRA) was applied to exhibit vascular signals. Transmission electron microscopy (TEM) was performed to detect the neurovascular unit (NVU) ultrastructure. Haematoxylin and eosin (HE) staining was utilized to evaluate cerebral histopathological lesions. The neurogenesis, angiogenesis, A1/A2 reactivity, aquaporin 4 (AQP4) and connexin 43 (Cx43) of astrocytes were observed with immunofluorescent staining. Then FGF2/PI3K/AKT signals were measured by western blot. Findings revealed TMP ameliorated neurological functional recovery, preserved NVU integrity, and enhanced endogenous neurogenesis and angiogenesis of rats with subacute ischemia. Shifting A1 to A2 reactivity, suppressing excessive AQP4 and Cx43 expression of astrocytes, and activating FGF2/PI3K/AKT pathway might be potential mechanisms of promoting neurovascular restoration with TMP after ischemic stroke.

Motor skills training-induced activation of descending pathways mediating cortical command to hindlimb motoneurons in experimental diabetic rats

Diabetes disrupts the corticospinal tract (CST) system components that control hindlimb and trunk movement, resulting in weakness of the lower extremities. However, there is no information about a method to improve these disorders. This study aimed to investigate the rehabilitative effects of 2 weeks of aerobic training (AT) and complex motor skills training (ST) on motor disorders in streptozotocin-induced type 1 diabetic rats. In this study, electrophysiological mapping of the motor cortex showed that the diabetes mellitus (DM)-ST group had a larger motor cortical area compared to the DM-AT group and sedentary diabetic animals. Moreover, hand grip strength and rotarod latency increased in the DM-ST group; however, these two parameters did not change in the DM-AT group, as well as in control and sedentary diabetic rats. Furthermore, in the DM-ST group, cortical stimulation-induced and motor-evoked potentials were preserved after the interception of the CST; however, this potential disappeared after additional lesions were made on lateral funiculus, suggesting that their function extends to activating motor descending pathways other than the CST locating lateral funiculus. According to immunohistochemical analysis, the larger fibers present on the dorsal part of the lateral funiculus, which corresponds to the rubrospinal tract of the DM-ST group, expressed the phosphorylated growth-associated protein, 43 kD, which is a specific marker of axons with plastic changes. Additionally, electrical stimulation of the red nucleus revealed expansion of the hindlimb-responsible area and increased motor-evoked potentials of the hindlimb in the DM-ST group, suggesting a strengthening of synaptic connections between the red nucleus and spinal interneurons driving motoneurons. These results reveal that ST induces plastic changes in the rubrospinal tract in a diabetic model, which can compensate for diabetes by disrupting the CST system components that control the hindlimb. This finding suggests that ST can be a novel rehabilitation strategy to improve motor dysfunctions in diabetic patients.

Early, Intense Rehabilitation Fails to Improve Outcome After Intra-Striatal Hemorrhage in Rats

BACKGROUND

The formation and degradation of an intracerebral hemorrhage causes protracted cell death, and an extended window for intervention. Experimental studies find that rehabilitation mitigates late cell death, with accelerated hematoma clearance as a potential mechanism.

OBJECTIVE

We assessed whether early, intense, enriched rehabilitation (ER, environmental enrichment and massed skills training) enhances functional benefit, reduces brain injury, and augments hematoma clearance.

METHODS

In experiment 1, rats (n = 56) were randomized to intervention in the light (-L) or dark phase (-D) of their housing cycle, then to 10 days of ER or control (CON) treatment after collagenase-induced striatal intracerebral hemorrhage (ICH). ER rats were treated from 5 to 14 days after ICH. Behavior and residual hematoma volume was assessed on day 14. In experiment 2, rats (n = 72) were randomized to ER-D10, ER-D20, or CON-D. ER rats completed 10 or 20 days of training in the dark. Rats were euthanized on day 60 for histology. In both experiments, behavioral assessment was completed pre-ICH, pre-ER (day 4 post-ICH), and post-ER (experiment 1: days 13-14; experiment 2: days 16-17 and 30-31).

RESULTS

Reaching intensity was high but similar between ER-D10 and ER-L10. Unlike previous work, rehabilitation did not alter skilled reaching or hematoma resolution. Varying ER duration also did not affect reaching success or lesion volume.

CONCLUSIONS

In contrast to others, and under these conditions, our findings show that striatal ICH was generally unresponsive to rehabilitation. This highlights the difficulty of replicating and extending published work, perhaps owing to small inter-study differences.

Swimming Training Mitigates Neurological Impairment of Intracerebral Haemorrhage in Mice via the Serine-Threonine Kinase/Glycogen Synthase Kinase 3β Signalling Pathway

Swimming training (ST) can mitigate functional disorders in neurological diseases, but the effect and mechanism of ST in improving the neurological function of intracerebral haemorrhage (ICH) have not been reported. Our study aimed to explore the protective effect of early ST on ICH mice and its relationship with the serine-threonine kinase (Akt)/glycogen synthase kinase 3β (GSK3β) pathway. Our findings showed that the ICH model mice had poor behavioural manifestations in the Y maze test and open field test compared to the ST group and sham group. The modified neurological severity score was increased in the ICH mice, and 7 days of ST intervention significantly attenuated the neurological deficits. The ratios of myo-inositol/creatine, lactate/creatine and glutamate/creatine were decreased, and the ratios of N-acetylaspartate/creatine and choline/creatine were increased in the ICH mice with ST intervention. ST intervention decreased the expression of Iba1 and GFAP. Seven days of ST significantly increased the expression of p-Akt/Akt compared to that in the ICH mice. Furthermore, the Akt kinase inhibitor GSK690693 exacerbated neurological impairment, increased the expression of Iba1, GFAP and Bax/Bcl-2, and reversed the anti-apoptotic effects and anti-glia activation of ST, which was associated with the inhibition of p-Akt/Akt and p-GSK3β/GSK3β expression. These results indicated that the protective role of ST in ICH was mediated via the Akt/GSK3β pathway. In conclusion, ST displayed neuroprotection by inhibiting apoptosis and glial activation in ICH mice by activating the Akt/GSK3β signalling pathway.

Effects of acrobatic training on spatial memory and astrocytic scar in CA1 subfield of hippocampus after chronic cerebral hypoperfusion in male and female rats

Chronic cerebral hypoperfusion leads to neuronal loss in the hippocampus and spatial memory impairments. Physical exercise is known to prevent cognitive deficits in animal models; and there is evidence of sex differences in behavioral neuroprotective approaches. The aim of present study was to investigate the effects of acrobatic training in male and female rats submitted to chronic cerebral hypoperfusion. Males and females rats underwent 2VO (two-vessel occlusion) surgery and were randomly allocated into 4 groups of males and 4 groups of females, as follows: 2VO acrobatic, 2VO sedentary, Sham acrobatic and Sham sedentary. The acrobatic training started 45 days after surgery and lasted 4 weeks; animals were then submitted to object recognition and water maze testing. Brain samples were collected for histological and morphological assessment and flow cytometry. 2VO causes cognitive impairments and acrobatic training prevented spatial memory deficits assessed in the water maze, mainly for females. Morphological analysis showed that 2VO animals had less NeuN labeling and acrobatic training prevented it. Increased number of GFAP positive cells was observerd in females; moreover, males had more branched astrocytes and acrobatic training prevented the branching after 2VO. Flow cytometry showed higher mitochondrial potential in trained animals and more reactive oxygen species production in males. Acrobatic training promoted neuronal survival and improved mitochondrial function in both sexes, and influenced the glial scar in a sex-dependent manner, associated to greater cognitive benefit to females after chronic cerebral hypoperfusion.

Effect of exercise from a very early stage after intracerebral hemorrhage on microglial and macrophage reactivity states in rats

OBJECTIVE

This study investigated the effects of exercise, starting very early after intracerebral hemorrhage (ICH), on microglia and macrophages in a rat model. Collagenase solution was injected into the left striatum to induce ICH.

METHODS

Rats were randomly assigned to receive placebo surgery without exercise (sham surgery), ICH without exercise (ICH), or ICH with very early exercise (ICH + VET). The ICH + VET group was subjected to treadmill running 6 h, 24 h, and days 2-6 after ICH. Motor function assessment was performed using the ladder test and rotarod test 3 h, 25 h, and 7 days after ICH. Postexercise brain tissue was collected on day 8 after surgery to investigate the lesion volume. Very early exercise temporarily worsened motor dysfunction. The protein expression levels of the macrophage and microglial markers CD80, CD163, and TMEM119 were analyzed 6 h, 24 h, and 8 days after ICH. Protein analysis of NeuN, GFAP, and PSD95 was also performed on day 8 after ICH.

RESULTS

There was no significant difference in lesion volume between the ICH and ICH + VET groups on day 8 after ICH. Exercise from very early stage prevented elevated CD163 protein expression.

CONCLUSION

Very early exercise may inhibit the activation of anti-inflammatory-associated macrophages/microglia.

Ferrostatin-1 Polarizes Microglial Cells Toward M2 Phenotype to Alleviate Inflammation After Intracerebral Hemorrhage

BACKGROUND

Intracerebral hemorrhage (ICH) is one of the most lethal stroke types and lacks effective therapeutic regimens. Recently, evidence has suggested the involvement of the ferroptosis inhibitor ferrostatin-1 (Fer-1) in the pathophysiological process of ICH. In this study, we examined the underlying mechanism.

METHODS

We induced an in vitro apoptosis model in organotypic hippocampal slice (OHS) using hemoglobin (Hb) and an in vivo ICH model using collagenase. OHSs were treated with MK-801, Fer-1, glutamate, and Hb to assess the impacts of Fer-1 on neuron apoptosis, glutathione peroxidase-4 activity, reactive oxygen species production, inflammation-related factors, expression of M1 markers and M2 markers, and the phagocytic function of microglial cells in vitro. Then, ICH mice were treated with Fer-1 and ruxolitinib to evaluate the effects of Fer-1-orchestrating janus kinase 1/signal transducer and activator of transcription 6 pathway on neurological function, brain water content, hematoma volume, the anti-inflammatory factor, M1 and M2 markers, and the phagocytic function of microglial cells in vivo.

RESULTS

Hb or glutamate facilitated glutathione peroxidase dysfunction, reactive oxygen species production, and neuronal apoptosis in OHSs, which was nullified by Fer-1. Fer-1 polarized microglial cells to the M2 phenotype, enhanced their phagocytic function, and prevented inflammation in Hb-induced OHSs. In the ICH mouse model, Fer-1 was found to improve neurological function and promote hematoma absorption. In addition, Fer-1 activated the Fer-1-orchestrating janus kinase 1/signal transducer and activator of transcription 6 pathway, which accelerated microglial M2 polarization, enhanced the phagocytic function of microglial cells, and restrained inflammation in ICH mice.

CONCLUSIONS

Overall, our findings suggest that Fer-1 may be a novel mechanism underlying microglial M2 polarization and inflammation after ICH.

Mouse model of voluntary movement deficits induced by needlestick injuries to the primary motor cortex

BACKGROUND

Motor handicap is prevalent in patients with traumatic brain injury, but currently. there is a challenging task to prevent the degeneration of motor neurons and to fully recover the. voluntary movement after injury.

NEW METHOD

For the first time, we propose to apply needlestick injuries to the primary motor cortex to create mouse model of voluntary movement deficits. Rotarod test, cylinder test and forepaw grip strength test were used to assay motor coordination of both C57BL/6 J and the triple immunodeficient NCG mice. Immunofluorescence staining of PKC-gamma, UCHL1, GFAP, Iba1 and Fluoro-Jade C was performed to analyze the numbers of motor neurons, microglia, astrocytes and degenerating neurons.

RESULTS

Mice on either C57BL/6 J or immunodeficient background with the unilateral primary motor cortex injury exhibit motor neuron death, activation of glial cells and deficits in voluntary movement.

CONCLUSIONS

The main finding of this study was that the unilateral primary motor cortex injured by needlesticks leads to reactive gliosis, motor neuron death and voluntary movement deficits in mice. This needlestick injury model of primary motor cortex might be useful for future exploration of underlying mechanisms of motor neuron degeneration and of promising treatment modalities such as cell transplantation to improve locomotor deficiency following neurotrauma.

Trillium tschonoskii rhizomes' saponins induces oligodendrogenesis and axonal reorganization for ischemic stroke recovery in rats

ETHNOPHARMACOLOGICAL RELEVANCE

Trillium tschonoskii Maxim. is one of traditional Chinese medical herbs that has been utilized to treat brain damages and cephalalgia. The neuroprotective effect of total saponins from Trillium tschonoskii rhizome (TSTT) has been demonstrated efficacy in rats following ischemia. However, the axonal remodeling effect of TSTT and the detailed mechanisms after ischemic stroke have not been investigated.

AIM OF THE STUDY

We aimed to estimate therapeutic role of TSTT in axonal remodeling using magnetic resonance imaging (MRI) technique, and explored possible mechanisms underlying this process followed by histological assays in ischemic rats.

METHODS

Male Sprague-Dawley (SD) rats underwent permanently focal cerebral ischemia induced by occluding right permanent middle cerebral artery. TSTT was intragastrically administrated 6 h after surgery and once daily for consecutive 15 days. Neurological function was assessed by the motor deficit score and beam walking test. T2 relaxation mapping and diffusion tensor imaging (DTI) were applied for detecting cerebral tissues damages and microstructural integrity of axons. Luxol fast blue (LFB) and transmission electron microscope (TEM) were performed to evaluate histopathology in myelinated axons. Double immunofluorescent staining was conducted to assess oligodendrogenesis. Furthermore, the protein expressions regarding to axonal remodeling related signaling pathways were detected by Western blot assays.

RESULTS

TSTT treatment (65, 33 mg/kg) markedly improved motor function after ischemic stroke. T2 mapping MRI demonstrated that TSTT decreased lesion volumes, and DTI further confirmed that TSTT preserved axonal microstructure of the sensorimotor cortex and internal capsule. Meanwhile, diffusion tensor tractography (DTT) showed that TSTT elevated correspondent density and length of fiber in the internal capsule. These MRI measurements were confirmed by histological examinations. Notably, TSTT significantly increased Ki67/NG2, Ki67/CNPase double-labeled cells along the boundary zone of ischemic cortex and striatum. Meanwhile, TSTT treatment up-regulated the phosphorylation level of Ser 9 in GSK-3β, and down-regulated phosphorylated β-catenin and CRMP-2 expression.

CONCLUSION

Taken together, our findings indicated that TSTT (65, 33 mg/kg) enhanced post-stroke functional recovery, amplified endogenous oligodendrogenesis and promoted axonal regeneration. The beneficial role of TSTT might be correlated with GSK-3/β-catenin/CRMP-2 modulating axonal reorganization after ischemic stroke.

Central Nervous System Tissue Regeneration after Intracerebral Hemorrhage: The Next Frontier

Despite marked advances in surgical techniques and understanding of secondary brain injury mechanisms, the prognosis of intracerebral hemorrhage (ICH) remains devastating. Harnessing and promoting the regenerative potential of the central nervous system may improve the outcomes of patients with hemorrhagic stroke, but approaches are still in their infancy. In this review, we discuss the regenerative phenomena occurring in animal models and human ICH, provide results related to cellular and molecular mechanisms of the repair process including by microglia, and review potential methods to promote tissue regeneration in ICH. We aim to stimulate research involving tissue restoration after ICH.

Behavioral Assessment of Sensory, Motor, Emotion, and Cognition in Rodent Models of Intracerebral Hemorrhage

Intracerebral hemorrhage (ICH) is the second most common type of stroke and has one of the highest fatality rates of any disease. There are many clinical signs and symptoms after ICH due to brain cell injury and network disruption resulted from the rupture of a tiny artery and activation of inflammatory cells, such as motor dysfunction, sensory impairment, cognitive impairment, and emotional disturbance, etc. Thus, researchers have established many tests to evaluate behavioral changes in rodent ICH models, in order to achieve a better understanding and thus improvements in the prognosis for the clinical treatment of stroke. This review summarizes existing protocols that have been applied to assess neurologic function outcomes in the rodent ICH models such as pain, motor, cognition, and emotion tests. Pain tests include mechanical, hot, and cold pain tests; motor tests include the following 12 types: neurologic deficit scale test, staircase test, rotarod test, cylinder test, grid walk test, forelimb placing test, wire hanging test, modified neurologic severity score, beam walking test, horizontal ladder test, and adhesive removal test; learning and memory tests include Morris water maze, Y-maze, and novel object recognition test; emotion tests include elevated plus maze, sucrose preference test, tail suspension test, open field test, and forced swim test. This review discusses these assessments by examining their rationale, setup, duration, baseline, procedures as well as comparing their pros and cons, thus guiding researchers to select the most appropriate behavioral tests for preclinical ICH research.

Very Early Exercise Rehabilitation After Intracerebral Hemorrhage Promotes Inflammation in the Brain

BACKGROUND

Very early exercise has been reported to exacerbate motor dysfunction; however, its mechanism is largely unknown.

OBJECTIVE

This study examined the effect of very early exercise on motor recovery and associated brain damage following intracerebral hemorrhage (ICH) in rats.

METHODS

Collagenase solution was injected into the left striatum to induce ICH. Rats were randomly assigned to receive placebo surgery without exercise (SHAM) or ICH without (ICH) or with very early exercise within 24 hours of surgery (ICH+VET). We observed sensorimotor behaviors before surgery, and after surgery preexercise and postexercise. Postexercise brain tissue was collected 27 hours after surgery to investigate the hematoma area, brain edema, and Il1b, Tgfb1, and Igf1 mRNA levels in the striatum and sensorimotor cortex using real-time reverse transcription polymerase chain reaction. NeuN, PSD95, and GFAP protein expression was analyzed by Western blotting.

RESULTS

We observed significantly increased skillful sensorimotor impairment in the horizontal ladder test and significantly higher Il1b mRNA levels in the striatum of the ICH+VET group compared with the ICH group. NeuN protein expression was significantly reduced in both brain regions of the ICH+VET group compared with the SHAM group.

CONCLUSION

Our results suggest that very early exercise may be associated with an exacerbation of motor dysfunction because of increased neuronal death and region-specific changes in inflammatory factors. These results indicate that implementing exercise within 24 hours after ICH should be performed with caution.

The Effects of Selective Inhibition of Histone Deacetylase 1 and 3 in Huntington's Disease Mice

Huntington's disease (HD) is an autosomal dominant neurodegenerative disease characterized by a late clinical onset of psychiatric, cognitive, and motor symptoms. Transcriptional dysregulation is an early and central disease mechanism which is accompanied by epigenetic alterations in HD. Previous studies demonstrated that targeting transcriptional changes by inhibition of histone deacetylases (HDACs), especially the class I HDACs, provides therapeutic effects. Yet, their exact mechanisms of action and the features of HD pathology, on which these inhibitors act remain to be elucidated. Here, using transcriptional profiling, we found that selective inhibition of HDAC1 and HDAC3 by RGFP109 alleviated transcriptional dysregulation of a number of genes, including the transcription factor genes Neurod2 and Nr4a2, and gene sets and programs, especially those that are associated to insulin-like growth factor pathway, in the striatum of R6/1 mice. RGFP109 treatment led to a modest improvement of the motor skill learning and coordination deficit on the RotaRod test, while it did not alter the locomotor and anxiety-like phenotypes in R6/1 animals. We also found, by volumetric MRI, a widespread brain atrophy in the R6/1 mice at the symptomatic disease stage, on which RGFP109 showed no significant effects. Collectively, our combined work suggests that specific HDAC1 and HDAC3 inhibition may offer benefits for alleviating the motor phenotypic deficits and transcriptional dysregulation in HD.

Effects of voluntary and forced exercises on motor function recovery in intracerebral hemorrhage rats

Motor paralysis is a severe consequence of intracerebral hemorrhage (ICH) that reduces patient quality of life. Rehabilitation is beneficial for stroke patients. However, functional recovery depends on the exercise type, and which factors are effective during rehabilitation are unknown. We aimed to clarify the effect of voluntary and forced exercises for functional recovery in ICH rats. Male Sprague-Dawley rats were divided into three groups: forced treadmill running (F-Ex.), voluntary wheel cage running (V-Ex.) and no exercise (Non-Ex.). The effects of the two exercises on motor recovery were analyzed by determining the motor deficit score and using the beam walking test. Stress and motivation status after rehabilitation were determined by corticosterone concentrations (ELISA) and immunoreactivity of ΔFosB (immunohistochemistry) in the nucleus accumbens, respectively. Significantly enhanced motor functional recovery was observed in the two trained groups compared with that in the Non-Ex. group. Of note, recovery in the V-Ex. group was greater than that in the F-Ex. group. To investigate the motivation and stress related to the exercises, the expression of ΔFosB in the nucleus accumbens and corticosterone concentration were compared after rehabilitation. In the V-Ex. group, there was a significant increase of ΔFosB, and in the F-Ex. Group, there was a high concentration of corticosterone. These data suggest that the effect of training for motor recovery was enhanced by motivation and reduced by stress.

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

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

Acrobatic exercise recovers object recognition memory impairment in hypoxic-ischemic rats

Neonatal hypoxia-ischemia (HI) can lead to cognitive impairments and motor dysfunction. Acrobatic exercises (AE) were proposing as therapeutic option to manage HI motor deficits, however, the cognitive effects after this treatment are still poorly understood. Therefore, we evaluated the effects of AE protocol on memory impairments and brain plasticity markers after Rice-Vannucci HI rodent model. Wistar rats on the 7th postnatal day (PND) were submitted to HI model and after weaning (PND22) were trained for 5 weeks with AE protocol, then subsequently submitted to cognitive tests. Our results showed recovery in novel object recognition (NOR) memory, but not, spatial Morris Water Maze (WM) memory after AE treatment in HI rats. BDNF and synaptophysin neuroplasticity markers indicate plastic alterations in the hippocampus and striatum, with maintenance of synaptophysin despite the reduction of total volume tissue, besides, hippocampal HI-induced ipsilateral BDNF increased, and striatum contralateral BDNF decreased were noted. Nevertheless, the exercise promoted functional recovery and seems to be a promising strategy for HI treatment, however, future studies identifying neuroplastic pathway for this improvement are needed.

Functional Recovery Patterns of Hemorrhagic and Ischemic Stroke Patients Under Post-Acute Care Rehabilitation Program

BACKGROUND

Tailored rehabilitation programs for stroke patients cannot be made without knowledge of their recovery potential. The aim of this study is to characterize the functional recovery patterns of ischemic stroke (IS) and intracerebral hemorrhage (ICH) patients under post-acute care stroke rehabilitation.

METHODS

This retrospective study analyzed the data of patients enrolled in the Post-Acute Care-Cerebrovascular Disease (PAC-CVD) rehabilitation program, which provides an individualized 1- to 3-hour intensive physical, occupational, and speech and language therapy for post-acute stroke patients in Taoyuan Chang Gung Memorial hospital in Taiwan. Our primary endpoint measure was Barthel Index (BI), and secondary endpoint measures included other 12 functional measures.

RESULTS

A total of 489 patients were included for analysis. Patients with stroke history had less BI improvement than those who suffered their first-ever stroke. In first-ever stroke patients who had completed 6 to 12 weeks of PAC-CVD program, subcortical ICH patients had greater BI, quality of life, sensation, and balance improvements, and had greater late-phase recovery than their IS counterparts. In IS patients, those with age >75 had less BI improvement; those with National Institute of Health Stroke Scale (NIHSS) score 1-5 had greater Motor Activity Log quality of use (MAL-quality) improvement than those with NIHSS score >5; those with Mini-Mental State Examination (MMSE) score ≥24 had greater BI and instrumental activities of daily living (IADL) improvement. Using the general linear model, previous stroke (ß: -6.148, p=0.01) and subcortical ICH (ß: 5.04, p=0.03) were factors associated with BI improvement.

CONCLUSION

Subcortical ICH patients have greater functional improvement and greater late-phase recovery than their IS counterparts following PAC rehabilitation. More studies are needed to validate our findings and unravel the underlying mechanisms of stroke recovery to optimize the treatment strategy following a stroke.

Modified constraint-induced movement therapy alters synaptic plasticity of rat contralateral hippocampus following middle cerebral artery occlusion

Modified constraint-induced movement therapy is an effective treatment for neurological and motor impairments in patients with stroke by increasing the use of their affected limb and limiting the contralateral limb. However, the molecular mechanism underlying its efficacy remains unclear. In this study, a middle cerebral artery occlusion (MCAO) rat model was produced by the suture method. Rats received modified constraint-induced movement therapy 1 hour a day for 14 consecutive days, starting from the 7^th day after middle cerebral artery occlusion. Day 1 of treatment lasted for 10 minutes at 2 r/min, day 2 for 20 minutes at 2 r/min, and from day 3 onward for 20 minutes at 4 r/min. CatWalk gait analysis, adhesive removal test, and Y-maze test were used to investigate motor function, sensory function as well as cognitive function in rodent animals from the 1^st day before MCAO to the 21^st day after MCAO. On the 21^st day after MCAO, the neurotransmitter receptor-related genes from both contralateral and ipsilateral hippocampi were tested by micro-array and then verified by western blot assay. The glutamate related receptor was shown by transmission electron microscopy and the glutamate content was determined by high-performance liquid chromatography. The results of behavior tests showed that modified constraint-induced movement therapy promoted motor and sensory functional recovery in the middle cerebral artery-occluded rats, but had no effect on cognitive function. The modified constraint-induced movement therapy upregulated the expression of glutamate ionotropic receptor AMPA type subunit 3 (Gria3) in the hippocampus and downregulated the expression of the beta3-adrenergic receptor gene Adrb3 and arginine vasopressin receptor 1A, Avpr1a in the middle cerebral artery-occluded rats. In the ipsilateral hippocampus, only Adra2a was downregulated, and there was no significant change in Gria3. Transmission electron microscopy revealed a denser distribution the more distribution of postsynaptic glutamate receptor 2/3, which is an α-amino-3-hydroxy-5-methyl-4-isoxazole-propionic acid receptor, within 240 nm of the postsynaptic density in the contralateral cornu ammonis 3 region. The size and distribution of the synaptic vesicles within 100 nm of the presynaptic active zone were unchanged. Western blot analysis showed that modified constraint-induced movement therapy also increased the expression of glutamate receptor 2/3 and brain-derived neurotrophic factor in the hippocampus of rats with middle cerebral artery occlusion, but had no effect on Synapsin I levels. Besides, we also found modified constraint-induced movement therapy effectively reduced glutamate content in the contralateral hippocampus. This study demonstrated that modified constraint-induced movement therapy is an effective rehabilitation therapy in middle cerebral artery-occluded rats, and suggests that these positive effects occur via the upregulation of the postsynaptic membrane α-amino-3-hydroxy-5-methyl-4-isoxazole-propionic acid receptor expression. This study was approved by the Institutional Animal Care and Use Committee of Fudan University, China (approval No. 201802173S) on March 3, 2018.

Exercise, spinogenesis and cognitive functions

Exercise training improves mental and cognitive functions by enhancing neurogenesis and neuroprotection. Recent studies suggest the facilitation of spinogenesis across different brain regions including hippocampus and cerebral cortex by physical activity. In this article we will summarize major findings for exercise effects on synaptogenesis and spinogenesis, in order to provide mechanisms for exercise intervention of both psychiatric diseases and neurodegenerative disorders. We will also revisit major findings for molecular mechanism governing exercise-related spinogenesis, and will discuss the screening for novel factors, or exerkines, whose levels are correlated with endurance training and affect neural plasticity. We believe that further studies focusing on the molecular mechanism of exercise-mediate spinogenesis should benefit the optimization of exercise therapy in clinics and the evaluation of treatment efficiency using specific biomarkers.

Treatment of secondary brain injury by perturbing postsynaptic density protein-95-NMDA receptor interaction after intracerebral hemorrhage in rats

Postsynaptic density protein-95 (PSD95) plays important roles in the formation, differentiation, remodeling, and maturation of neuronal synapses. This study is to estimate the potential role of PSD95 in cognitive dysfunction and synaptic injury following intracerebral hemorrhage (ICH). The interaction between PSD95 and NMDA receptor subunit NR2B-neurotransmitter nitric oxide synthase (nNOS) could form a signal protein complex mediating excitatory signaling. Besides NR2B-nNOS, PSD95 also can bind to neurexin-1-neuroligin-1 to form a complex and participates in maintaining synaptic function. In this study, we found that there were an increase in the formation of PSD95-NR2B-nNOS complex and a decrease in the formation of neurexin-1-neuroligin-1-PSD95 complex after ICH, and this was accompanied by increased neuronal death and degeneration, and behavior dysfunction. PSD95 inhibitor Tat-NR2B9c effectively inhibited the interaction between PSD95 and NR2B-nNOS, and promoted the formation of neurexin-1-nueuroligin-1-PSD95 complex. In addition, Tat-NR2B9c treatment significantly reduced neuronal death and degeneration and matrix metalloproteinase 9 activity, alleviated inflammatory response and neurobehavioral disorders, and improved the cognitive and learning ability of ICH rats. Inhibition of the formation of PSD95-NR2B-nNOS complex can rescue secondary brain injury and behavioral cognitive impairment after ICH. PSD95 is expected to be a target for improving the prognosis of patients with ICH.

Neonatal hypoxia-ischemia caused mild motor dysfunction, recovered by acrobatic training, without affecting morphological structures involved in motor control in rats

The aim of this study was to evaluated motor function and morphological aspects of the components involved in motor control (sensorimotor cortex, spinal cord, sciatic nerve, neuromuscular junctions and skeletal muscle) in male Wistar rats exposed to a model of neonatal hypoxic-ischemic encephalopathy (HIE) and the possible influence of different physical exercise protocols - treadmill and acrobatic. Male Wistar rats at the 7^th post-natal day (PND) were submitted to the HIE model and from the 22^nd until 60^th PND the exercise protocols (treadmill or acrobatic training) were running. After the training, the animals were evaluated in Open Field, Ladder Rung Walking and Rotarod tasks and after samples of the motor control components were collected. Our results evidenced that the acrobatic training reversed the hyperactivity and anxiety, caused locomotion improvement and decreased brain atrophy in HIE animals. We did not find morphological differences on sensorimotor cortex, spinal cord, sciatic nerve, neuromuscular junctions and skeletal muscle in the animals submitted to HIE model. These intriguing data support the statement of the Rice-Vannucci model does not seem to reproduce, in structures involved in control function, the damage found in humans that suffer HIE. Regarding the protocols of exercise, we proposed that the acrobatic exercise could be a good therapeutic option especially in children affected by neonatal HIE and can be responsible for good results in cognitive and motor aspects.

Quantitative proteomic analysis of intracerebral hemorrhage in rats with a focus on brain energy metabolism

INTRODUCTION

Intracerebral hemorrhage (ICH) is a lethal cerebrovascular disorder with a high mortality and morbidity. The pathophysiological mechanisms underlying ICH-induced secondary injury remain unclear.

METHODS

To examine one of the gaps in the knowledge about ICH pathological mechanisms, isobaric tag for relative and absolute quantification (iTRAQ)-based liquid chromatography-tandem mass spectrometry (LC-MS/MS) was used in collagenase-induced ICH rats on the 2nd day.

RESULTS

A total of 6,456 proteins were identified with a 1% false discovery rate (FDR). Of these proteins, 126 and 75 differentially expressed proteins (DEPs) were substantially increased and decreased, respectively. Based on Gene Ontology (GO), Kyoto Encyclopedia of Genes and Genomes (KEGG), and STRING analyses, the protein changes in cerebral hemorrhage were comprehensively evaluated, and the energy metabolism in ICH was anchored. The core position of the nitrogen metabolism pathway in brain metabolism in ICH was found for the first time. Carbonic anhydrase 1 (Ca1), carbonic anhydrase 2 (Ca2), and glutamine synthetase (Glul) participated in this pathway. We constructed the protein-protein interaction (PPI) networks for the energy metabolism of ICH, including the Atp6v1a-Atp6v0c-Atp6v0d1-Ppa2-Atp6ap2 network.

CONCLUSIONS

It seems that dysregulation of energy metabolism, especially nitrogen metabolism, may be a major cause in secondary ICH injury. This information provides novel insights into secondary events following ICH.

Ultrastructural Characteristics of Neuronal Death and White Matter Injury in Mouse Brain Tissues After Intracerebral Hemorrhage: Coexistence of Ferroptosis, Autophagy, and Necrosis

Although intracerebral hemorrhage (ICH) is a devastating disease worldwide, the pathologic changes in ultrastructure during the acute and chronic phases of ICH are poorly described. In this study, transmission electron microscopy was used to examine the ultrastructure of ICH-induced pathology. ICH was induced in mice by an intrastriatal injection of collagenase. Pathologic changes were observed in the acute (3 days), subacute (6 days), and chronic (28 days) phases. Compared with sham animals, we observed various types of cell death in the injured striatum during the acute phase of ICH, including necrosis, ferroptosis, and autophagy. Different degrees of axon degeneration in the striatum were seen in the acute phase, and axonal demyelination was observed in the ipsilateral striatum and corpus callosum at late time points. In addition, phagocytes, resident microglia, and infiltrating monocyte-macrophages were present around red blood cells and degenerating neurons and were observed to engulf red blood cells and other debris. Many synapses appeared abnormal or were lost. This systematic analysis of the pathologic changes in ultrastructure after ICH in mice provides information that will be valuable for future ICH pathology studies.

Rehabilitation following hemorrhagic stroke: building the case for stroke-subtype specific recovery therapies

Intracerebral hemorrhage (ICH), a form of brain bleeding and minor subtype of stroke, leads to significant mortality and long-term disability. There are currently no validated approaches to promote functional recovery after ICH. Research in stroke recovery and rehabilitation has largely focused on ischemic stroke, but given the stark differences in the pathophysiology between ischemic and hemorrhagic stroke, it is possible that strategies to rehabilitate the brain in distinct stroke subtypes will be different. Here, we review our current understanding of recovery after primary intracerebral hemorrhage with the intent to provide a framework to promote novel, stroke-subtype specific approaches.

Exercise-Induced Neuroprotection of the Nigrostriatal Dopamine System in Parkinson's Disease

Epidemiological studies indicate that physical activity and exercise may reduce the risk of developing Parkinson's disease (PD), and clinical observations suggest that physical exercise can reduce the motor symptoms in PD patients. In experimental animals, a profound observation is that exercise of appropriate timing, duration, and intensity can reduce toxin-induced lesion of the nigrostriatal dopamine (DA) system in animal PD models, although negative results have also been reported, potentially due to inappropriate timing and intensity of the exercise regimen. Exercise may also minimize DA denervation-induced medium spiny neuron (MSN) dendritic atrophy and other abnormalities such as enlarged corticostriatal synapse and abnormal MSN excitability and spiking activity. Taken together, epidemiological studies, clinical observations, and animal research indicate that appropriately dosed physical activity and exercise may not only reduce the risk of developing PD in vulnerable populations but also benefit PD patients by potentially protecting the residual DA neurons or directly restoring the dysfunctional cortico-basal ganglia motor control circuit, and these benefits may be mediated by exercise-triggered production of endogenous neuroprotective molecules such as neurotrophic factors. Thus, exercise is a universally available, side effect-free medicine that should be prescribed to vulnerable populations as a preventive measure and to PD patients as a component of treatment. Future research needs to establish standardized exercise protocols that can reliably induce DA neuron protection, enabling the delineation of the underlying cellular and molecular mechanisms that in turn can maximize exercise-induced neuroprotection and neurorestoration in animal PD models and eventually in PD patients.

Exacerbation of Brain Injury by Post-Stroke Exercise Is Contingent Upon Exercise Initiation Timing

Accumulating evidence has demonstrated that post-stroke physical rehabilitation may reduce morbidity. The effectiveness of post-stroke exercise, however, appears to be contingent upon exercise initiation. This study assessed the hypothesis that very early exercise exacerbates brain injury, induces reactive oxygen species (ROS) generation, and promotes energy failure. A total of 230 adult male Sprague-Dawley rats were subjected to middle cerebral artery (MCA) occlusion for 2 h, and randomized into eight groups, including two sham injury control groups, three non-exercise and three exercise groups. Exercise was initiated after 6 h, 24 h and 3 days of reperfusion. Twenty-four hours after completion of exercise (and at corresponding time points in non-exercise controls), infarct volumes and apoptotic cell death were examined. Early brain oxidative metabolism was quantified by examining ROS, ATP and NADH levels 0.5 h after completion of exercise. Furthermore, protein expressions of angiogenic growth factors were measured in order to determine whether post-stroke angiogenesis played a role in rehabilitation. As expected, ischemic stroke resulted in brain infarction, apoptotic cell death and ROS generation, and diminished NADH and ATP production. Infarct volumes and apoptotic cell death were enhanced (p < 0.05) by exercise that was initiated after 6 h of reperfusion, but decreased by late exercise (24 h, 3 days). This exacerbated brain injury at 6 h was associated with increased ROS levels (p < 0.05), and decreased (p < 0.05) NADH and ATP levels. In conclusion, very early exercise aggravated brain damage, and early exercise-induced energy failure with ROS generation may underlie the exacerbation of brain injury. These results shed light on the manner in which exercise initiation timing may affect post-stroke rehabilitation.

Neural Plasticity in Moderate to Severe Chronic Stroke Following a Device-Assisted Task-Specific Arm/Hand Intervention

Currently, hand rehabilitation following stroke tends to focus on mildly impaired individuals, partially due to the inability for severely impaired subjects to sufficiently use the paretic hand. Device-assisted interventions offer a means to include this more severe population and show promising behavioral results. However, the ability for this population to demonstrate neural plasticity, a crucial factor in functional recovery following effective post-stroke interventions, remains unclear. This study aimed to investigate neural changes related to hand function induced by a device-assisted task-specific intervention in individuals with moderate to severe chronic stroke (upper extremity Fugl-Meyer < 30). We examined functional cortical reorganization related to paretic hand opening and gray matter (GM) structural changes using a multimodal imaging approach. Individuals demonstrated a shift in cortical activity related to hand opening from the contralesional to the ipsilesional hemisphere following the intervention. This was driven by decreased activity in contralesional primary sensorimotor cortex and increased activity in ipsilesional secondary motor cortex. Additionally, subjects displayed increased GM density in ipsilesional primary sensorimotor cortex and decreased GM density in contralesional primary sensorimotor cortex. These findings suggest that despite moderate to severe chronic impairments, post-stroke participants maintain ability to show cortical reorganization and GM structural changes following a device-assisted task-specific arm/hand intervention. These changes are similar as those reported in post-stroke individuals with mild impairment, suggesting that residual neural plasticity in more severely impaired individuals may have the potential to support improved hand function.

Preventive motor training but not progenitor grafting ameliorates cerebellar ataxia and deregulated autophagy in tambaleante mice

Treatment options for degenerative cerebellar ataxias are currently very limited. A large fraction of such disorders is represented by hereditary cerebellar ataxias, whose familiar transmission facilitates an early diagnosis and may possibly allow to start preventive treatments before the onset of the neurodegeneration and appearance of first symptoms. In spite of the heterogeneous aetiology, histological alterations of ataxias often include the primary degeneration of the cerebellar cortex caused by Purkinje cells (PCs) loss. Thus, approaches aimed at replacing or preserving PCs could represent promising ways of disease management. In the present study, we compared the efficacy of two different preventive strategies, namely cell replacement and motor training. We used tambaleante (tbl) mice as a model for progressive ataxia caused by selective loss of PCs and evaluated the effectiveness of the preventive transplantation of healthy PCs into early postnatal tbl cerebella, in terms of PC replacement and functional preservation. On the other hand, we investigated the effects of motor training on PC survival, cerebellar circuitry and their behavioral correlates. Our results demonstrate that, despite a good survival rate and integration of grafted PCs, the adopted grafting protocol could not alleviate the ataxic symptoms in tbl mice. Conversely, preventive motor training increases PCs survival with a moderate positive impact on the motor phenotype.

Enhanced apoptosis from early physical exercise rehabilitation following ischemic stroke

The effectiveness of the rehabilitative benefits of physical exercise appears to be contingent upon when the exercise is initiated after stroke. The present study assessed the hypothesis that very early exercise increases the extent of apoptotic cell death via increased expression of proapoptotic proteins in a rat stroke model. Adult male Sprague-Dawley rats were subjected to middle cerebral artery occlusion (MCAO) for 2 hr using an intraluminal filament and assigned to four nonexercise and three exercise groups. Exercise on a Rota-Rod was initiated for 30 min at 6 hr (considered very early), at 24 hr (early), and at 3 days (relatively late) after reperfusion. At 24 hr after exercise, apoptotic cell death was determined. At 3 and 24 hr after exercise, the expression of pro- and antiapoptotic proteins was evaluated through Western blotting. As expected, ischemic stroke significantly increased the levels of apoptotic cell death. Compared with the stroke group without exercise, apoptotic cell death was further increased (P < 0.05) at 6 hr but not at 24 hr or 3 days with exercise. This exacerbated cell injury was associated with increased expression of proapoptotic proteins (BAX and caspase-3). The expression of Bcl-2, an antiapoptotic protein, was not affected by exercise. In ischemic stroke, apoptotic cell death was enhanced by very early exercise in association with increased expression of proapoptotic proteins. These results shed light on the time-sensitive effect of exercise in poststroke rehabilitation. © 2016 Wiley Periodicals, Inc.

Early rehabilitation aggravates brain damage after stroke via enhanced activation of nicotinamide adenine dinucleotide phosphate oxidase (NOX)

INTRODUCTION

Although physical exercise has emerged as a potential therapeutic modality for functional deficits following ischemic stroke, the extent of this effect appears to be contingent upon the time of exercise initiation. In the present study, we assessed how exercise timing affected brain damage through hyperglycolysis-associated NADPH oxidase (NOX) activation.

METHODS

Using an intraluminal filament, adult male Sprague-Dawley rats were subjected to middle cerebral artery occlusion (MCAO) for 2h and assigned to one non-exercise and three exercise groups. Exercise on Rota-rod was initiated for 30min at 6h (considered very early), at 24h (early), and at day 3 (relatively late) after reperfusion. Lactate production was measured 30min after exercise completion, and NOX activity and protein expression of NOX subunits (p47(phox), gp91(phox), p22(phox) and p67(phox)) and glucose transporter 1 and 3 (Glut-1 and -3) were measured at 3 and 24h after exercise. Apoptotic cell death was determined at 24h after exercise.

RESULTS

Lactate production and Glut-1 and Glut-3 expression were increased after very early exercise (6h), but not after late exercise (3 days), suggesting hyperglycolysis. NOX activity was increased with the initiation of exercise at 6h (P<0.05), but not 24h or 3 days, following stroke. Early (6 and 24h), but not late (3 days), post-stroke exercise was associated with increased (P<0.05) expression of the NOX protein subunit p47(phox), gp91(phox)and p67(phox). This may have led to the enhanced apoptosis observed after early exercise in ischemic rats.

CONCLUSION

Hyperglycolysis and NOX activation was associated with an elevation in apoptotic cell death after very early exercise, and the detrimental effect of exercise on stroke recovery began to decrease when exercise was initiated 24h after reperfusion.

Moderate exercise prevents neurodegeneration in D-galactose-induced aging mice

D-galactose has been widely used in aging research because of its efficacy in inducing senescence and accelerating aging in animal models. The present study investigated the benefits of exercise for preventing neurodegeneration, such as synaptic plasticity, spatial learning and memory abilities, in mouse models of aging. D-galactose-induced aging mice were administered daily subcutaneous injections of D-galactose at the base of the neck for 10 consecutive weeks. Then, the mice were subjected to exercise training by running on a treadmill for 6 days a week. Shortened escape latency in a Morris water maze test indicated that exercise improved learning and memory in aging mice. The ameliorative changes were likely induced by an upregulation of Bcl-2 and brain-derived neurotrophic factor, the repression of apoptosis factors such as Fas and Bax, and an increase in the activity of glucose transporters-1 and 4. The data suggest moderate exercise may retard or inhibit neurodegeneration in D-galactose-induced aging mice.

Recovery and Rehabilitation after Intracerebral Hemorrhage

About half of patients survive intracerebral hemorrhage (ICH), but most are left with significant disability. Rehabilitation after ICH is the mainstay of treatment to reduce impairment, improve independence in activities, and return patients to meaningful participation in the community. The authors discuss the neuroplastic mechanisms underlying recovery in ICH, preclinical and clinical interventional studies to augment recovery, and the rehabilitative and medical management of post-ICH patients.

Hydrogen sulfide improves neural function in rats following cardiopulmonary resuscitation

The alleviation of brain injury is a key issue following cardiopulmonary resuscitation (CPR). Hydrogen sulfide (H₂S) is hypothesized to be involved in the pathophysiological process of ischemia-reperfusion injury, and exerts a protective effect on neurons. The aim of the present study was to investigate the effects of H₂S on neural functions following cardiac arrest (CA) in rats. A total of 60 rats were allocated at random into three groups. CA was induced to establish the model and CPR was performed after 6 min. Subsequently, sodium hydrosulfide (NaHS), hydroxylamine or saline was administered to the rats. Serum levels of H₂S, neuron-specific enolase (NSE) and S100β were determined following CPR. In addition, neurological deficit scoring (NDS), the beam walking test (BWT), prehensile traction test and Morris water maze experiment were conducted. Neuronal apoptosis rates were detected in the hippocampal region following sacrifice. After CPR, as the H₂S levels increased or decreased, the serum NSE and S100β concentrations decreased or increased, respectively (P<0.0w. The NDS results of the NaHS group were improved compared with those of the hydroxylamine group at 24 h after CPR (P<0.05). In the Morris water maze experiment, BWT and prehensile traction test the animals in the NaHS group performed best and rats in the hydroxylamine group performed worst. At day 7, the apoptotic index and the expression of caspase-3 were reduced in the hippocampal CA1 region, while the expression of Bcl-2 increased in the NaHS group; and results of the hydroxylamine group were in contrast. Therefore, the results of the present study indicate that H₂S is able to improve neural function in rats following CPR.

Running exercise enhances motor functional recovery with inhibition of dendritic regression in the motor cortex after collagenase-induced intracerebral hemorrhage in rats

Rehabilitative approaches benefit motor functional recovery after stroke and relate to neuronal plasticity. We investigated the effects of a treadmill running exercise on the motor functional recovery and neuronal plasticity after collagenase-induced striatal intracerebral hemorrhage (ICH) in rats. Male Wistar rats were injected with type IV collagenase into the left striatum to induce ICH. Sham-operated animals were injected with saline instead of collagenase. The animals were randomly assigned to the sham control (SC), the sham exercise (SE), the ICH control (IC), or the ICH exercise (IE) group. The exercise groups were forced to run on a treadmill at a speed of 9 m/min for 30 min/day between days 4 and 14 after surgery. Behavioral tests were performed using a motor deficit score, a beam-walking test and a cylinder test. At fifteen days after surgery, the animals were sacrificed, and their brains were removed. The motor function of the IE group significantly improved compared with the motor function of the IC group. No significant differences in cortical thickness were found between the groups. The IC group had fewer branches and shorter dendrite lengths compared with the sham groups. However, dendritic branches and lengths were not significantly different between the IE and the other groups. Tropomyosin-related kinase B (TrkB) expression levels increased in the IE compared with IC group, but no significant differences in other protein (brain-derived neurotrophic factor, BDNF; Nogo-A; Rho-A/Rho-associated protein kinase 2, ROCK2) expression levels were found between the groups. These results suggest that improved motor function after a treadmill running exercise after ICH may be related to the prevention of dendritic regression due to TrkB upregulation.

Intracerebral hemorrhage in mouse models: therapeutic interventions and functional recovery

There has been strong pre-clinical research on mechanisms of initial cell death and tissue injury in intracerebral hemorrhage (ICH). This data has led to the evaluation of several therapeutics for neuroprotection or the mitigation of early tissue damage. Most of these studies have been done in the rat. Also, there has been little study of the mechanisms of tissue repair and recovery. This review examines the testing of candidate therapeutics in mouse models of ICH for their effect on tissue protection and repair. This review will help the readers compare it to the extensively researched rat model of ICH and thus enhance work that are pending in mouse model.