scholarly journals Effects of Tetramethylpyrazine on Functional Recovery and Neuronal Dendritic Plasticity after Experimental Stroke

2015 ◽  
Vol 2015 ◽  
pp. 1-10 ◽  
Author(s):  
Jun-Bin Lin ◽  
Chan-Juan Zheng ◽  
Xuan Zhang ◽  
Juan Chen ◽  
Wei-Jing Liao ◽  
...  
Keyword(s):  
Ischemic Stroke ◽  
Functional Recovery ◽  
Classical Model ◽  
Significant Negative Correlation ◽  
Artery Occlusion ◽  
Neurological Function ◽  
Experimental Stroke ◽  
Spine Density ◽  
Dendritic Plasticity ◽  
Cerebral Artery Occlusion

The 2,3,5,6-tetramethylpyrazine (TMP) has been widely used in the treatment of ischemic stroke by Chinese doctors. Here, we report the effects of TMP on functional recovery and dendritic plasticity after ischemic stroke. A classical model of middle cerebral artery occlusion (MCAO) was established in this study. The rats were assigned into 3 groups: sham group (sham operated rats treated with saline), model group (MCAO rats treated with saline) and TMP group (MCAO rats treated with 20 mg/kg/d TMP). The neurological function test of animals was evaluated using the modified neurological severity score (mNSS) at 3 d, 7 d, and 14 d after MCAO. Animals were euthanized for immunohistochemical labeling to measure MAP-2 levels in the peri-infarct area. Golgi-Cox staining was performed to test effect of TMP on dendritic plasticity at 14 d after MCAO. TMP significantly improved neurological function at 7 d and 14 d after ischemia, increased MAP-2 level at 14 d after ischemia, and enhanced spine density of basilar dendrites. TMP failed to affect the spine density of apical dendrites and the total dendritic length. Data analyses indicate that there was significant negative correlation between mNSS and plasticity measured at 14 d after MCAO. Thus, enhanced dendritic plasticity contributes to TMP-elicited functional recovery after ischemic stroke.

Abstract WP118: The Flavanol (-)-Epicatechin Improves Functional Recovery In Mice Subjected To Experimental Stroke

Stroke ◽  
2013 ◽  
Vol 44 (suppl_1) ◽  
Author(s):  
Christopher C Leonardo ◽  
Sean Robbins ◽  
Abdullah A Ahmad ◽  
Sylvain Dore
Keyword(s):  
Functional Recovery ◽  
Transcriptional Activation ◽  
Infarct Volume ◽  
Epidemiological Studies ◽  
Artery Occlusion ◽  
Experimental Stroke ◽  
Adhesive Tape ◽  
Dietary Consumption ◽  
Therapeutic Doses ◽  
Cerebral Artery Occlusion

Background: Epidemiological studies indicate that flavanol consumption reduces the propensity to develop cerebrovascular disease. Available data suggest actions on multiple pro-inflammatory pathways, yet it remains unclear which pathways mediate functional recovery after stroke. Our goal is to begin identifying the mechanisms by which the flavanol (-)-epicatechin (EC) improves anatomical and functional outcomes. Based upon data from initial dose-response experiments, ongoing studies are investigating hypothesized protective pathways involving matrix metalloproteinase-mediated blood brain barrier protection and Nrf2 transcriptional activation. Methods: Male, 8-10wk old C57BL/6 mice were pretreated with EC 90m prior to permanent distal middle cerebral artery occlusion. Vehicle or EC was administered by oral gavage to mimic dietary consumption. Mice were evaluated 1, 4 and 7d post-stroke for performance on various sensorimotor tasks prior to histological assessments. Results: Initial experiments demonstrated that mice treated with 15mg/kg EC showed reduced latency to remove adhesive tape at 1d compared to vehicle controls (n=12, p<0.01). Similarly, immunoreactivity for the microglia/macrophage marker Iba1 was increased in the ipsilateral hemispheres of mice 7d after treatment with vehicle (p<0.01), whereas pretreatment with 15mg/kg blocked this effect (n=4). Mice treated with 15mg/kg also showed a trend toward reduced infarct volume relative to vehicle controls (n=5-9 per group). In subsequent reduced dosing studies, vehicle-treated mice again showed deficiencies in removing adhesive tape at 1d (n=8, p<0.01). Remarkably, mice treated with 15, 10 or 5mg/kg EC showed no deficits. Similarly, vehicle control mice showed grip strength impairments up to 7d (n=8, p<0.05) that were absent in all groups of EC-treated mice. Conclusions: Preventative administration of EC promotes functional recovery in mice subjected to experimental stroke. Investigations are underway to determine the pathways mediated by EC following administration at these therapeutic doses. Together, these data will provide insights into the potential for (-)-epicatechin as a clinical therapeutic.

scholarly journals Delayed inhibition of tonic inhibition enhances functional recovery following experimental ischemic stroke

2017 ◽  
Vol 39 (6) ◽  
pp. 1005-1014 ◽  
Author(s):  
James E Orfila ◽  
Himmat Grewal ◽  
Robert M Dietz ◽  
Frank Strnad ◽  
Takeru Shimizu ◽  
...  
Keyword(s):  
Ischemic Stroke ◽  
Functional Recovery ◽  
Ex Vivo ◽  
Long Term Potentiation ◽  
Artery Occlusion ◽  
Memory Impairments ◽  
Time Points ◽  
Term Potentiation ◽  
Cerebral Artery Occlusion

The current study focuses on the ability to improve cognitive function after stroke with interventions administered at delayed/chronic time points. In light of recent studies demonstrating delayed GABA antagonists improve motor function, we utilized electrophysiology, biochemistry and neurobehavioral methods to investigate the role of α5 GABAA receptors on hippocampal plasticity and functional recovery following ischemic stroke. Male C57Bl/6 mice were exposed to 45 min transient middle cerebral artery occlusion and analysis of synaptic and functional deficits performed 7 or 30 days after recovery. Our findings indicate that hippocampal long-term potentiation (LTP) is impaired 7 days after stroke and remain impaired for at least 30 days. We demonstrate that ex vivo administration of L655,708 reversed ischemia-induced plasticity deficits and importantly, in vivo administration at delayed time-points reversed stroke-induced memory deficits. Western blot analysis of hippocampal tissue reveals proteins responsible for GABA synthesis are upregulated (GAD65/67 and MAOB), increasing GABA in hippocampal interneurons 30 days after stroke. Thus, our data indicate that both synaptic plasticity and memory impairments observed after stroke are caused by excessive tonic GABA activity, making inhibition of specific GABA activity at delayed timepoints a potential therapeutic approach to improve functional recovery and reverse cognitive impairments after stroke.

scholarly journals Intracerebral Delivery of Brain-Derived Neurotrophic Factor Using HyStem®-C Hydrogel Implants Improves Functional Recovery and Reduces Neuroinflammation in a Rat Model of Ischemic Stroke

2018 ◽  
Vol 19 (12) ◽  
pp. 3782 ◽  
Author(s):  
Kristine Ravina ◽  
Denise Briggs ◽  
Sezen Kislal ◽  
Zuha Warraich ◽  
Tiffany Nguyen ◽  
...  
Keyword(s):  
Ischemic Stroke ◽  
Functional Recovery ◽  
Neurotrophic Factor ◽  
Infarct Volume ◽  
Brain Derived Neurotrophic Factor ◽  
Artery Occlusion ◽  
Sensorimotor Function ◽  
Neural Repair ◽  
Adhesive Removal ◽  
Cerebral Artery Occlusion

Ischemic stroke is a leading cause of death and disability worldwide. Potential therapeutics aimed at neural repair and functional recovery are limited in their blood-brain barrier permeability and may exert systemic or off-target effects. We examined the effects of brain-derived neurotrophic factor (BDNF), delivered via an extended release HyStem®-C hydrogel implant or vehicle, on sensorimotor function, infarct volume, and neuroinflammation, following permanent distal middle cerebral artery occlusion (dMCAo) in rats. Eight days following dMCAo or sham surgery, treatments were implanted directly into the infarction site. Rats received either vehicle, BDNF-only (0.167 µg/µL), hydrogel-only, hydrogel impregnated with 0.057 µg/µL of BDNF (hydrogel + BDNFLOW), or hydrogel impregnated with 0.167 µg/µL of BDNF (hydrogel + BDNFHIGH). The adhesive removal test (ART) and 28-point Neuroscore (28-PN) were used to evaluate sensorimotor function up to two months post-ischemia. The hydrogel + BDNFHIGH group showed significant improvements on the ART six to eight weeks following treatment and their behavioral performance was consistently greater on the 28-PN. Infarct volume was reduced in rats treated with hydrogel + BDNFHIGH as were levels of microglial, phagocyte, and astrocyte marker immunoexpression in the corpus striatum. These data suggest that targeted intracerebral delivery of BDNF using hydrogels may mitigate ischemic brain injury and restore functional deficits by reducing neuroinflammation.

scholarly journals CD28 Superagonist-Mediated Boost of Regulatory T Cells Increases Thrombo-Inflammation and Ischemic Neurodegeneration during the Acute Phase of Experimental Stroke

2014 ◽  
Vol 35 (1) ◽  
pp. 6-10 ◽  
Author(s):  
Michael K Schuhmann ◽  
Peter Kraft ◽  
Guido Stoll ◽  
Kristina Lorenz ◽  
Sven G Meuth ◽  
...  
Keyword(s):  
T Cells ◽  
Ischemic Stroke ◽  
Regulatory T Cells ◽  
Thrombus Formation ◽  
Inflammatory Lesion ◽  
Artery Occlusion ◽  
Acute Stage ◽  
Experimental Stroke ◽  
Cerebral Artery Occlusion

While the detrimental role of non-regulatory T cells in ischemic stroke is meanwhile unequivocally recognized, there are controversies about the properties of regulatory T cells (Treg). The aim of this study was to elucidate the role of Treg by applying superagonistic anti-CD28 antibody expansion of Treg. Stroke outcome, thrombus formation, and brain-infiltrating cells were determined on day 1 after transient middle cerebral artery occlusion. Antibody-mediated expansion of Treg enhanced stroke size and worsened functional outcome. Mechanistically, Treg increased thrombus formation in the cerebral microvasculature. These findings confirm that Treg promote thrombo-inflammatory lesion growth during the acute stage of ischemic stroke.

scholarly journals Delayed Reperfusion Deficits after Experimental Stroke Account for Increased Pathophysiology

2014 ◽  
Vol 35 (2) ◽  
pp. 277-284 ◽  
Author(s):  
Fiona E Burrows ◽  
Natasha Bray ◽  
Adam Denes ◽  
Stuart M Allan ◽  
Ingo Schiessl
Keyword(s):  
Ischemic Stroke ◽  
Artery Occlusion ◽  
Therapeutic Interventions ◽  
Experimental Stroke ◽  
Initial Increase ◽  
Significant Drop ◽  
Sham Surgery ◽  
Interleukin 1Α ◽  
Oxygen Perfusion ◽  
Cerebral Artery Occlusion

Cerebral blood flow and oxygenation in the first few hours after reperfusion following ischemic stroke are critical for therapeutic interventions but are not well understood. We investigate changes in oxyhemoglobin (HbO2) concentration in the cortex during and after ischemic stroke, using multispectral optical imaging in anesthetized mice, a remote filament to induce either 30 minute middle cerebral artery occlusion (MCAo), sham surgery or anesthesia alone. Immunohistochemistry establishes cortical injury and correlates the severity of damage with the change of oxygen perfusion. All groups were imaged for 6 hours after MCAo or sham surgery. Oxygenation maps were calculated using a pathlength scaling algorithm. The MCAo group shows a significant drop in HbO2 during occlusion and an initial increase after reperfusion. Over the subsequent 6 hours HbO2 concentrations decline to levels below those observed during stroke. Platelets, activated microglia, interleukin-1α, evidence of BBB breakdown and neuronal stress increase within the stroked hemisphere and correlate with the severity of the delayed reperfusion deficit but not with the ΔHbO2 during stroke. Despite initial restoration of HbO2 after 30 min MCAo there is a delayed compromise that coincides with inflammation and could be a target for improved stroke outcome after thrombolysis.

scholarly journals The Hsp90 Inhibitor 17-DMAG Attenuates Hyperglycemia-Enhanced Hemorrhagic Transformation in Experimental Stroke

2021 ◽  
Vol 2021 ◽  
pp. 1-7
Author(s):  
Jiaming Zhang ◽  
Kai Wang ◽  
Jia Qi ◽  
Xiaodong Cao ◽  
Feng Wang
Keyword(s):  
Ischemic Stroke ◽  
Hsp90 Inhibitor ◽  
Hemorrhagic Transformation ◽  
Artery Occlusion ◽  
Vital Role ◽  
Experimental Stroke ◽  
Acute Hyperglycemia ◽  
Inflammatory Molecules ◽  
Cerebral Artery Occlusion ◽  
The Brain

Introduction. Hemorrhagic transformation (HT) is one of the most common complications of ischemic stroke which is exacerbated by hyperglycemia. Oxidative stress, inflammatory response, and matrix metalloproteinases (MMPs) have been evidenced to play a vital role in the pathophysiology of HT. Our previous study has reported that 17-DMAG, an Hsp90 inhibitor, protects the brain against ischemic injury via inhibiting inflammation and reducing MMP-9 after ischemia. However, whether 17-DMAG would attenuate HT in hyperglycemic middle cerebral artery occlusion (MCAO) rats is still unknown. Methods. Acute hyperglycemia was induced by an injection of 50% dextrose. Rats were pretreated with 17-DMAG before MCAO. Infarction volume, hemorrhagic volume neurological scores, expressions of inflammatory molecules and tight junction proteins, and activity of MMP-2 and MMP-9 were assessed 24 h after MCAO. Results. 17-DMAG was found to reduce HT, improve neurological function, and inhibit expressions of inflammatory molecules and the activation of MMPs at 24 h after MCAO. Conclusion. These results implicated that Hsp90 could be a novel therapeutic target in HT following ischemic stroke.

scholarly journals Improved reperfusion following alternative surgical approach for experimental stroke in mice

F1000Research ◽  
2020 ◽  
Vol 9 ◽  
pp. 188
Author(s):  
Melissa Trotman-Lucas ◽  
Raymond Wong ◽  
Stuart M. Allan ◽  
Claire L. Gibson
Keyword(s):  
Ischemic Stroke ◽  
Surgical Approach ◽  
Artery Occlusion ◽  
Laser Speckle ◽  
Experimental Stroke ◽  
Contrast Imaging ◽  
Ipsilateral Hemisphere ◽  
Cerebral Artery Occlusion ◽  
The Brain

Background: Following ischemic stroke, recanalisation and restoration of blood flow to the affected area of the brain is critical and directly correlates with patient recovery.  In vivo models of ischemic stroke show high variability in outcomes, which may be due to variability in reperfusion.  We previously reported that a surgical refinement in the middle cerebral artery occlusion (MCAO) model of stroke, via repair of the common carotid artery (CCA), removes the reliance on the Circle of Willis for reperfusion and reduced infarct variability.  Here we further assess this refined surgical approach on reperfusion characteristics following transient MCAO in mice. Methods: Mice underwent 60 min of MCAO, followed by either CCA repair or ligation at reperfusion.  All mice underwent laser speckle contrast imaging at baseline, 24 h and 48 h post-MCAO. Results: CCA ligation reduced cerebral perfusion in the ipsilateral hemisphere compared to baseline (102.3 ± 4.57%) at 24 h (85.13 ± 16.09%; P < 0.01) and 48 h (75.04 ± 12.954%; P < 0.001) post-MCAO. Repair of the CCA returned perfusion to baseline (94.152 ± 2.44%) levels and perfusion was significantly improved compared to CCA ligation at both 24 h (102.83 ± 8.41%; P < 0.05) and 48 h (102.13 ± 9.34%; P < 0.001) post-MCAO. Conclusions: Our findings show CCA repair, an alternative surgical approach for MCAO, results in improved ischemic hemisphere perfusion during the acute phase.

scholarly journals Improved reperfusion following alternative surgical approach for experimental stroke in mice

F1000Research ◽  
2020 ◽  
Vol 9 ◽  
pp. 188
Author(s):  
Melissa Trotman-Lucas ◽  
Raymond Wong ◽  
Stuart M. Allan ◽  
Claire L. Gibson
Keyword(s):  
Ischemic Stroke ◽  
Surgical Approach ◽  
Artery Occlusion ◽  
Laser Speckle ◽  
Experimental Stroke ◽  
Contrast Imaging ◽  
Ipsilateral Hemisphere ◽  
Cerebral Artery Occlusion ◽  
The Brain

Background: Following ischemic stroke, recanalisation and restoration of blood flow to the affected area of the brain is critical and directly correlates with patient recovery.  In vivo models of ischemic stroke show high variability in outcomes, which may be due to variability in reperfusion.  We previously reported that a surgical refinement in the middle cerebral artery occlusion (MCAO) model of stroke, via repair of the common carotid artery (CCA), removes the reliance on the Circle of Willis for reperfusion and reduced infarct variability.  Here we further assess this refined surgical approach on reperfusion characteristics following transient MCAO in mice. Methods: Mice underwent 60 min of MCAO, followed by either CCA repair or ligation at reperfusion.  All mice underwent laser speckle contrast imaging at baseline, 24 h and 48 h post-MCAO. Results: CCA ligation reduced cerebral perfusion in the ipsilateral hemisphere compared to baseline (102.3 ± 4.57%) at 24 h (85.13 ± 16.09%; P < 0.01) and 48 h (75.04 ± 12.954%; P < 0.001) post-MCAO. Repair of the CCA returned perfusion to baseline (94.152 ± 2.44%) levels and perfusion was significantly improved compared to CCA ligation at both 24 h (102.83 ± 8.41%; P < 0.05) and 48 h (102.13 ± 9.34%; P < 0.001) post-MCAO. Conclusions: Our findings show CCA repair, an alternative surgical approach for MCAO, results in improved ischemic hemisphere perfusion during the acute phase.

scholarly journals Infarct Growth Precedes Cerebral Thrombosis Following Experimental Stroke in Mice

2021 ◽  
Author(s):  
Vanessa Göb ◽  
Maximilian G. Voll ◽  
Lena Zimmermann ◽  
Katherina Hemmen ◽  
Guido Stoll ◽  
...  
Keyword(s):  
Ischemic Stroke ◽  
Tissue Damage ◽  
Thrombus Formation ◽  
Brain Slices ◽  
Light Sheet ◽  
Artery Occlusion ◽  
Experimental Stroke ◽  
Cerebral Thrombosis ◽  
Cerebral Artery Occlusion ◽  
Kinetics Of

Abstract Ischemic stroke is among the leading causes of disability and death worldwide. In acute ischemic stroke, successful recanalization of occluded vessels is the primary therapeutic aim, but even if it is achieved, not all patients benefit. Although blockade of platelet aggregation did not prevent infarct progression, cerebral thrombosis as cause of secondary infarct growth has remained a matter of debate. As cerebral thrombi are frequently observed after experimental stroke, a thrombus-induced impairment of the brain microcirculation is considered to contribute to tissue damage. Here, we combine the model of transient middle cerebral artery occlusion (tMCAO) with light sheet fluorescence microscopy and immunohistochemistry of brain slices to investigate the kinetics of thrombus formation and infarct progression. Our data reveal that tissue damage already peaks after 8 h of reperfusion following 60 min MCAO, while cerebral thrombi are only observed at later time points. Thus, cerebral thrombosis is not causative for secondary infarct growth during ischemic stroke.

scholarly journals Improved reperfusion following alternative surgical approach for experimental stroke in mice

F1000Research ◽  
2020 ◽  
Vol 9 ◽  
pp. 188
Author(s):  
Melissa Trotman-Lucas ◽  
Raymond Wong ◽  
Stuart M. Allan ◽  
Claire L. Gibson
Keyword(s):  
Ischemic Stroke ◽  
Surgical Approach ◽  
Artery Occlusion ◽  
Laser Speckle ◽  
Experimental Stroke ◽  
Contrast Imaging ◽  
Ipsilateral Hemisphere ◽  
Cerebral Artery Occlusion ◽  
The Brain

Background: Following ischemic stroke, recanalisation and restoration of blood flow to the affected area of the brain is critical and directly correlates with patient recovery.  In vivo models of ischemic stroke show high variability in outcomes, which may be due to variability in reperfusion.  We previously reported that a surgical refinement in the middle cerebral artery occlusion (MCAO) model of stroke, via repair of the common carotid artery (CCA), removes the reliance on the Circle of Willis for reperfusion and reduced infarct variability.  Here we further assess this refined surgical approach on reperfusion characteristics following transient MCAO in mice. Methods: Mice underwent 60 min of MCAO, followed by either CCA repair or ligation at reperfusion.  All mice underwent laser speckle contrast imaging at baseline, 24 h and 48 h post-MCAO. Results: CCA ligation reduced cerebral perfusion in the ipsilateral hemisphere compared to baseline (102.3 ± 4.57%) at 24 h (85.13 ± 16.09%; P < 0.01) and 48 h (75.04 ± 12.954%; P < 0.001) post-MCAO. Repair of the CCA returned perfusion to baseline (94.152 ± 2.44%) levels and perfusion was significantly improved compared to CCA ligation at both 24 h (102.83 ± 8.41%; P < 0.05) and 48 h (102.13 ± 9.34%; P < 0.001) post-MCAO. Conclusions: Our findings show CCA repair, an alternative surgical approach for MCAO, results in improved ischemic hemisphere perfusion during the acute phase.

Sign in / Sign up

Export Citation Format

Share Document