scholarly journals Power spectrum slope and motor function recovery after focal cerebral ischemia in the rat

2018 ◽  
Author(s):  
Susan Leemburg ◽  
Bo Gao ◽  
Ertugrul Cam ◽  
Johannes Sarnthein ◽  
Claudio L. Bassetti
Keyword(s):  
Power Spectrum ◽  
Motor Function ◽  
Focal Cerebral Ischemia ◽  
Recovery Period ◽  
Artery Occlusion ◽  
Experimental Stroke ◽  
Stroke Models ◽  
Eeg Changes ◽  
Cerebral Artery Occlusion ◽  
Spectrum Slope

AbstractEEG changes across vigilance states have been observed after ischemic stroke in patients and experimental stroke models, but their relation to functional recovery remains unclear. Here, we evaluate motor function, as measured by single pellet reaching (SPR), as well as local EEG changes in NREM, REM and wakefulness during a 30-day recovery period after middle cerebral artery occlusion (MCAO) or sham surgery in rats. Small cortical infarcts resulted in poor SPR performance and induced widespread changes in EEG spectra in the ipsilesional hemisphere in all vigilance states, without causing major changes in sleep-wake architecture. Ipsilesional 1–4 Hz power was increased after stroke, whereas power in higher frequencies was reduced, resulting in a steeper slope of the power spectrum. Multielectrode array analysis of ipsilesional M1 showed that these spectral changes were present on the microelectrode level throughout M1 and were not related to increased synchronization between electrodes. Spectrum slope was significantly correlated with post-stroke motor function.

scholarly journals Power spectrum slope is related to motor function after focal cerebral ischemia in the rat

SLEEP ◽  
2018 ◽  
Vol 41 (10) ◽  
Author(s):  
Susan Leemburg ◽  
Bo Gao ◽  
Ertugrul Cam ◽  
Johannes Sarnthein ◽  
Claudio L Bassetti
Keyword(s):  
Cerebral Ischemia ◽  
Power Spectrum ◽  
Motor Function ◽  
Focal Cerebral Ischemia ◽  
Spectrum Slope

scholarly journals Enriched Environment Reduces Apolipoprotein E (ApoE) in Reactive Astrocytes and Attenuates Inflammation of the Peri-Infarct Tissue after Experimental Stroke

2009 ◽  
Vol 29 (11) ◽  
pp. 1796-1805 ◽  
Author(s):  
Karsten Ruscher ◽  
Emelie Johannesson ◽  
Elena Brugiere ◽  
Agnes Erickson ◽  
Mattias Rickhag ◽  
...  
Keyword(s):  
Apolipoprotein E ◽  
Interleukin 1 ◽  
Recovery Period ◽  
Artery Occlusion ◽  
Enriched Environment ◽  
Reactive Astrocytes ◽  
Experimental Stroke ◽  
Housing Conditions ◽  
Tissue Reorganization ◽  
Cerebral Artery Occlusion

Apolipoprotein E (ApoE), a cholesterol transporter and an immunomodulator, is brain protective after experimental stroke and implicated in brain repair. Here, we study the involvement of ApoE in the restoration of brain function after experimental stroke, by using animal housing conditions that differentially improve recovery after occlusion of the middle cerebral artery occlusion (MCAO). We found that after MCAO the ApoE levels increased in the injured hemisphere over a 30 days recovery period. The exception was a proximal narrow peri-infarct rim, in which ApoE was solely localized in S100 β+/glial fibrillary acidic protein (GFAP) negative reactive astrocytes at 4 to 7 days of recovery. Enriched housing after MCAO caused a marked decrease in ApoE levels compared with standard housing conditions, particularly in the ApoE/S100 β+ reactive astrocytes. In addition, the levels of interleukin 1 β were lower in animals housed in an enriched environment. We propose that during the subacute phase after experimental stroke a zone for tissue reorganization with low cellular ApoE levels is formed. We conclude that the strong sensori-motor stimulation provided by enriched housing conditions mitigates the inflammatory response after stroke decreasing the level of ApoE that may contribute to the observed improvement of functional recovery.

scholarly journals Lempel-Ziv complexity of the EEG predicts long-term functional recovery after stroke in rats

2018 ◽  
Author(s):  
Susan Leemburg ◽  
Claudio L. Bassetti
Keyword(s):  
Motor Function ◽  
Functional Recovery ◽  
Brain Function ◽  
Complexity Analysis ◽  
Recovery Period ◽  
Artery Occlusion ◽  
Multiscale Entropy ◽  
Experimental Stroke ◽  
Reaching Task ◽  
Post Stroke

AbstractNon-linear complexity of the EEG signal can be used to detect abnormal brain function relating to behavioral deficits. Here, we compare the effects of experimental stroke on EEG complexity using Lempel-Ziv complexity analysis (LZC) and multiscale entropy analysis (SampEn).EEG was recorded in bilateral motor cortex at baseline and during a 30-day recovery period after distal middle cerebral artery occlusion in rats. Motor function was assessed using a single pellet reaching task. Stroke caused an acute drop in both LZC and SampEn in the ipsilesional hemisphere in wakefulness, NREM and REM sleep, as well as reduced pellet reaching success. SampEn reductions persisted for at least 10 days post-stroke, whereas LZC had returned to baseline levels by day 4. EEG complexity in the contralesional hemisphere and in sham-operated animals were unaffected.If EEG complexity reflects post-stroke brain function, post-stroke asymmetry could be used to predict behavioral recovery. In rats, acute LZC asymmetry was significantly correlated with the amount of motor function recovery by post-stroke day 31, but SampEn asymmetry was not. EEG LZC may thus be a useful tool for predicting functional recovery after stroke. MSE could be effective in identifying cortical dysfunction, but does not reflect behavioral outcomes.

scholarly journals Neuroprotective Effects of a Novel Nitrone, NXY-059, after Transient Focal Cerebral Ischemia in the Rat

1999 ◽  
Vol 19 (7) ◽  
pp. 778-787 ◽  
Author(s):  
Satoshi Kuroda ◽  
Ryoichi Tsuchidate ◽  
Maj-Lis Smith ◽  
Kirk R. Maples ◽  
Bo K. Siesjö
Keyword(s):  
Focal Cerebral Ischemia ◽  
Infarct Volume ◽  
Recovery Period ◽  
Artery Occlusion ◽  
Transfer Constant ◽  
Neuroprotective Effects ◽  
Transient Focal Cerebral Ischemia ◽  
Therapeutic Opportunity ◽  
Cerebral Artery Occlusion ◽  
Antiischemic Effect

Recent results have demonstrated that the spin trapping agent α-phenyl- N- tert-butyl nitrone (PBN) reduces infarct volume in rats subjected to 2 hours of middle cerebral artery occlusion, even when given 1 to 3 hours after the start of recirculation. In the current study, the authors assessed the effect of NXY-059, a novel nitrone that is more soluble than PBN. Loading doses were given of 0.30, 3.0, or 30 mg · kg−1 followed by 0.30, 3.0, or 30 mg · kg−1 · h−1 for 24 or 48 hours. Dose–response studies showed that when treatment was begun 1 hour after recirculation, 0.30 mg · kg−1 had a small and 30 mg · kg-i a marked effect on infarct volume. At equimolar doses (3.0 mg · kg−1 for NXY-059 and 1.4 mg · kg−1 for PBN), NXY-059 was more efficacious than PBN. Similar results were obtained when a recovery period of 7 days was allowed. The window of therapeutic opportunity for NXY-059 was 3 to 6 hours after the start of recirculation. Studies of the transfer constant of [14C]NXY-059 showed that, in contrast to PBN, this more soluble nitrone penetrates the blood-brain barrier less extensively. This fact, and the pronounced antiischemic effect of NXY-059, suggest that the delayed events leading to infarction may be influenced by reactions occurring at the blood–endothelial interface.

scholarly journals Administration of Selective Endothelin Receptor Type a Antagonist Ro 61-1790 Does Not Improve Outcome in Focal Cerebral Ischemia in Cat

2000 ◽  
Vol 20 (3) ◽  
pp. 499-504 ◽  
Author(s):  
Anish Bhardwaj ◽  
Ying Wu ◽  
Patricia D. Hurn ◽  
Jeffrey R. Kirsch ◽  
Richard J. Traystman
Keyword(s):  
Focal Cerebral Ischemia ◽  
Plasma Concentrations ◽  
Type A ◽  
Artery Occlusion ◽  
Receptor Type ◽  
Experimental Stroke ◽  
Cranial Window ◽  
Pial Arterioles ◽  
Cerebral Artery Occlusion ◽  
Structure Score

The authors examined the effect of selective endothelin (ET) receptor type A (ETA) antagonism on histological and functional recovery in cat at 24 hours after reversible middle cerebral artery occlusion (MCAO). A novel and specific ETA antagonist, Ro 61-1790 [5-methylpyridine-2-sulfonic acid-6-(2-hydroxyethoxy)-5-(2-methoxyphenoxy)-2-(2-1 H-tetrazol-5-yl-pyridin-4-yl)-pyrimidin-4-ylamide sodium salt (1:2)] (Roche, Basel, Switzerland), was used at doses that produced steady-state plasma concentrations and abolished ET-induced pial arteriolar vasoconstriction. In a cranial window preparation, 8 nmol/L ET constricted pial arterioles by 33 ± 18% (mean ± SD), but this response was ablated by intravenous Ro 61-1790 treatment (10-mg/kg bolus, 4-mg/kg/h infusion). In additional animal cohorts, halothane-anesthetized cats were treated with 90 minutes of MCAO and 24 hours of reperfusion. Animals received Ro 61-1790 infusion beginning at the onset of reperfusion and continuing for 6 or 24 hours (n = 41). Control cats were treated with 0.9% saline by intravenous infusion throughout reperfusion. There was no difference in injury volume or neurologic evaluation score in saline-treated cats (n = 11; caudate 24 ± 28%, cortical injury 7.5 ± 5% of ipsilateral structure; score 52 ± 8) versus the results in cats treated with Ro 61-1790 for either 24 hours (n = 6; caudate 22 ± 23%, cortex 6 ± 5%, injury volume of ipsilateral structure; score 55 ± 3) or 6 hours (n = 11; caudate 33 ± 30%, cortex 12 ± 14%, injury volume of ipsilateral structure; score 50 ± 10). Mortality was greatest in the 24-hour drug treatment group. These data suggest that blockade of ETA receptor activity is not beneficial to tissue or functional outcomes from experimental stroke in cat.

scholarly journals Knockout of Silent Information Regulator 2 (SIRT2) Preserves Neurological Function after Experimental Stroke in Mice

2015 ◽  
Vol 35 (12) ◽  
pp. 2080-2088 ◽  
Author(s):  
Lea Krey ◽  
Fred Lühder ◽  
Kathrin Kusch ◽  
Bozena Czech-Zechmeister ◽  
Birte Könnecke ◽  
...  
Keyword(s):  
Ischemic Stroke ◽  
Cerebral Ischemia ◽  
Focal Cerebral Ischemia ◽  
Brain Regions ◽  
Artery Occlusion ◽  
Neurological Deficits ◽  
Experimental Stroke ◽  
Wild Type ◽  
Significant Difference ◽  
Stroke Models

Sirtuin-2 (Sirt2) is a member of the NAD+-dependent protein deacetylase family. Various members of the sirtuin class have been found to be involved in processes related to longevity, regulation of inflammation, and neuroprotection. Induction of Sirt2 mRNA was found in the whole hemisphere after experimental stroke in a recent screening approach. Moreover, Sirt2 protein is highly expressed in myelin-rich brain regions after stroke. To examine the effects of Sirt2 on ischemic stroke, we induced transient focal cerebral ischemia in adult male Sirt2-knockout and wild-type mice. Two stroke models with different occlusion times were applied: a severe ischemia (45 minutes of middle cerebral artery occlusion (MCAO)) and a mild one (15 minutes of MCAO), which was used to focus on subcortical infarcts. Neurological deficit was determined at 48 hours after 45 minutes of MCAO, and up to 7 days after induction of 15 minutes of cerebral ischemia. In contrast to recent data on Sirt1, Sirt2−/− mice showed less neurological deficits in both models of experimental stroke, with the strongest manifestation after 48 hours of reperfusion. However, we did not observe a significant difference of stroke volumes or inflammatory cell count between Sirt2-deficient and wild-type mice. Thus we postulate that Sirt2 mediates myelin-dependent neuronal dysfunction during the early phase after ischemic stroke.

Abstract 91: Remodeling After Stroke: The Recovering Brain Is Vulnerable To Lipoxygenase-dependent Semaphorin Signaling

Stroke ◽  
2013 ◽  
Vol 44 (suppl_1) ◽  
Author(s):  
Anton Pekcec ◽  
Kazim Yigitkanli ◽  
Joo Eun Jung ◽  
Hulya Karatas ◽  
Eng H Lo ◽  
...  
Keyword(s):  
Knockout Mice ◽  
Cortical Neurons ◽  
Second Messengers ◽  
Artery Occlusion ◽  
Tube Formation ◽  
Stroke Recovery ◽  
Experimental Stroke ◽  
Axon Extension ◽  
Cultured Cortical Neurons ◽  
Cerebral Artery Occlusion

Background and Purpose— Recovery from stroke is limited in part by an inhibitory environment in the post-ischemic brain, but factors preventing successful remodeling are not well known. We sought to investigate if signaling from the axon guidance molecule semaphorin 3A (Sema3A) via eicosanoid second messengers can contribute to this inhibitory environment, and if blocking the Sema3A pathway can provide a benefit following experimental stroke. Methods— Cultured cortical neurons from mice were treated with recombinant Sema3A, or with the eicosanoids 12-HETE and 12-HPETE. Neurons from ALOX15 knockout mice, and a human brain endothelial cell line, were treated similarly. The filament model of MCAO was used to induce experimental stroke in mice, in some of which Sema3A was injected stereotactically into the striatum. The 12/15-LOX inhibitor LOXBlock-1 was injected intraperitoneally one week after MCAO. Results— Expression levels of 12/15-lipoxygenase (12/15-LOX) were increased within two hours after exposure of primary neurons to 90nM recombinant Sema3A. Either Sema3A, or the 12/15-lipoxygenase (12/15-LOX) metabolites 12-HETE and 12-HPETE at 300nM, blocked axon extension in neurons compared to solvent controls, and decreased tube formation in endothelial cells. The Sema3A effect was reversed by inhibiting 12/15-LOX, and neurons derived from 12/15-LOX knockout mice were insensitive to Sema3A. Following middle cerebral artery occlusion to induce stroke in mice, immunohistochemistry showed both Sema3A and 12/15-LOX are increased in the cortex up to two weeks. To determine if a Sema3A-dependent damage pathway is activated following ischemia, we injected recombinant Sema3A into the striatum. Sema3A alone did not cause injury in normal brains. But when injected into post-ischemic brains, Sema3A increased cortical damage by 79%, and again this effect was reversed by 12/15-LOX inhibition. Administration of the 12/15-LOX inhibitor LOXBlock-1 7 days after transient MCAO increased vascularization in the infarcted and peri-infarct area one week later. Conclusions— Our findings suggest that blocking the semaphorin pathway may provide a novel therapeutic strategy to improve stroke recovery.

scholarly journals Relation of Apparent Diffusion Coefficient Changes and Metabolic Disturbances after 1 Hour of Focal Cerebral Ischemia and at Different Reperfusion Phases in Rats

2001 ◽  
Vol 21 (4) ◽  
pp. 430-439 ◽  
Author(s):  
Laszlo Olah ◽  
Stefan Wecker ◽  
Mathias Hoehn
Keyword(s):  
Energy Metabolism ◽  
Cerebral Ischemia ◽  
Middle Cerebral Artery ◽  
Focal Cerebral Ischemia ◽  
Artery Occlusion ◽  
Atp Depletion ◽  
Apparent Diffusion ◽  
Tissue Acidosis ◽  
Cerebral Artery Occlusion ◽  
Energy Failure

Changes in apparent diffusion coefficients (ADC) were compared with alterations of adenosine triphosphate (ATP) concentration and pH in different phases of transient focal cerebral ischemia to study the ADC threshold for breakdown of energy metabolism and tissue acidosis during ischemia and reperfusion. Male Wistar rats underwent 1 hour of middle cerebral artery occlusion without recirculation (n = 3) or with 1 hour (n = 4) or 10 hours of reperfusion (n = 5) inside the magnet, using a remotely controlled thread occlusion model. ADC maps were calculated from diffusion-weighted images and normalized to the preischemic value to obtain relative ADC maps. Hemispheric lesion volume (HLV) was determined on the last relative ADC maps at different relative ADC thresholds and was compared to the HLV measured by ATP depletion and by tissue acidosis. The HLVs, defined by ATP depletion and tissue acidosis, were 26.0% ± 10.6% and 38.1% ± 6.5% at the end of ischemia, 3.3% ± 2.4% and 4.8% ± 3.5% after 1 hour of reperfusion, and 11.2% ± 4.7% and 10.9% ± 5.2% after 10 hours of recirculation, respectively. The relative ADC thresholds for energy failure were consistently approximately 77% of the control value in the three different groups. The threshold for tissue acidosis was higher at the end of ischemia (86% of control) but was similar to the results obtained for ATP depletion after 1 hour (78% of control) and 10 hours (76% of control) of recirculation. These results indicate that the described relative ADC threshold of approximately 77% of control provides a good estimate for the breakdown of energy metabolism not only during middle cerebral artery occlusion but also at the early phase of reperfusion, when recovery of energy metabolism is expected to occur, or some hours later, when development of secondary energy failure was described.

scholarly journals Leukocyte-Endothelium Interactions during Permanent Focal Cerebral Ischemia in Mice

2004 ◽  
Vol 24 (6) ◽  
pp. 668-676 ◽  
Author(s):  
Hiroharu Kataoka ◽  
Seong-Woong Kim ◽  
Nikolaus Plesnila
Keyword(s):  
Cerebral Ischemia ◽  
Brain Damage ◽  
Molecular Mechanisms ◽  
Focal Cerebral Ischemia ◽  
Fluorescent Microscopy ◽  
Capillary Density ◽  
Artery Occlusion ◽  
Cerebral Artery Occlusion ◽  
Adherent Leukocytes

The contribution of leukocyte infiltration to brain damage after permanent focal cerebral ischemia and the underlying molecular mechanisms are still unclear. Therefore, the aim of this study was to establish a mouse model for the visualization of leukocytes in the cerebral microcirculation in vivo and to investigate leukocyte-endothelial interaction (LEI) after permanent middle cerebral artery occlusion (MCAO). Sham-operated 129/Sv mice showed physiologic LEI in pial venules as observed by intravital fluorescent microscopy. Permanent focal cerebral ischemia induced a significant increase of LEI predominantly in pial venules. The number of rolling and adherent leukocytes reached 36.5 ± 13.2/100 μm × min and 22.5 ± 7.9/100 μm × min, respectively at 120 minutes after MCAO ( P = 0.016 vs. control). Of note, rolling and adherent leukocytes were also observed in arterioles of ischemic animals (7.3 ± 3.0/100 μm × min rolling and 3.0 ± 3.6/100 μm × min adherent). Capillary density was not different between groups. These results demonstrate that leukocytes accumulate in the brain not only after transient but also after permanent focal cerebral ischemia and may therefore contribute to brain damage after stroke without reperfusion.

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