Immunohistochemistry and double immunofluorescent labeling techniques combined with confocal laser scanning microscope analysis were used to investigate the characteristic spatial induction profile of nestin following a transient middle cerebral artery occlusion in adult rat brain. The results showed that nestin was induced in ischemic core at 1 day after reperfusion. In addition to ischemic core, the expression of nestin increased in peri-ischemic I, II and III regions at 3 days and 1 week, then it decreased and narrowed along the rim of ischemic core 2 weeks after reperfusion. Double immunofluorescent labeling showed that nestin positive cells were mostly co-stained with GFAP,a astrocyte marker, in peri-ischemic I region 3 days after reperfusion. At 2 weeks, however nestin cells showed a long process and the cells double stained with nestin and NSE,a neuonal specific marker,increased in the ischemic brain. The results suggest that cerebral ischemia induces nestin expression in damaged neurons which might favor the neuroprotection against ischemic damage.
Animals ; Brain ; metabolism ; pathology ; Brain Ischemia ; metabolism ; pathology ; Immunohistochemistry ; Infarction, Middle Cerebral Artery ; metabolism ; pathology ; Nestin ; metabolism ; Neurons ; metabolism ; Rats

OBJECTIVETo investigate whether there is endogenous neural stem cell proliferation and whether these proliferated neural stem cells represent neural plasticity in the adult rats after cerebral infarction.

METHODSCerebral infarction models of rats were established and the dynamic expression of bromodeoxyuridine (BrdU), BrdU/polysialylated neural cell adhesion molecule (PSA-NCAM) were determined by immunohistochemistry and immunofluorescence staining. BrdU was used to mark dividing neural stem cells. PSA-NCAM was used to mark the plasticity of neural stem cells.

RESULTSCompared with controls, the number of BrdU-positive cells in the subventricular zone (SVZ) and hippocampus increased significantly at 1st day after cerebral infarction (P < 0.05), reached maximum at 7th day, decreased markedly at 14th day, but it was still elevated compared with that of the controls (P < 0.05). The number of BrdU-labeled with PSA-NCAM-positive cells increased significantly at 7th day (P < 0.05), reached maximum at 14th day, markedly decreased at 28th day, but it was still elevated compared with that of the controls (P < 0.05). It was equal to 60% of the number of BrdU-positive cells in the same period.

CONCLUSIONCerebral infarction may stimulate the proliferation of endogenous neural stem cells in situ and most proliferated neural stem cells represent neural plasticity.

Animals ; Bromodeoxyuridine ; metabolism ; Cell Proliferation ; Cerebral Infarction ; metabolism ; pathology ; Cerebral Ventricles ; pathology ; Hippocampus ; pathology ; Male ; Neural Cell Adhesion Molecule L1 ; metabolism ; Neuronal Plasticity ; Neurons ; metabolism ; pathology ; Rats ; Rats, Wistar ; Sialic Acids ; metabolism ; Stem Cells ; metabolism ; pathology

OBJECTIVEHypoxic-ischemic encephalopathy (HIE) is an important cause of morbidity and mortality in the neonates. Early and accurate diagnosis is helpful not only for assessing prognosis but also for making treatment decisions. The aim of this study was to explore the value of early assessment of HIE by applying the diffusion-weighted imaging (DWI) in acute (within 72 hours), subacute or chronic stages of HIE in comparison to conventional magnetic resonance imaging (MRI) in clinical practice.

METHODSImages and clinical charts of fourteen term neonates with clinically diagnosed severe hypoxic-ischemic encephalopathy treated in the NICU from January 2006 to February 2007 were retrospectively reviewed. Inclusion criteria were: term infant (37 approximately 42 weeks) and high clinical suspicion of severe HIE (low Apgar scores, need for resuscitation, metabolic acidosis, acute encephalopathy (eg, hypotonia, coma, seizures). All examinations were performed on a 3.0-T MRI system (Philips Intera Acheva Magnetom Vision) with echo-planar imaging capability with the use of a standard protocol. The imaging protocol for all the patients contained diffuse weighted images (EPI-SE, TR = 2144 ms, TE = 56 ms), T1-weighted images (TR = 389 ms; TE = 15 ms; slice thickness = 4 mm) as well as T2-weighted images (TR = 3035 ms; TE = 100 ms; slice thickness = 4 mm). The studies were first performed within 72 hours of life in these 14 consecutive patients, including both standard T1, T2-weighted image and DWI; follow-up MR studies were performed for 4 patients at the ages of 7 days, for 4 at 14 days, for another 3 at ages of both 21 days and 8 months.

RESULTSFirst inspection (on an average of 48 hours after birth): routine T1, T2-weighted images showed normal images in all patients, while diffusion images showed symmetric high intensity signal in the lateral thalami and posterior limbs of internal capsules (PLIC). Following up: on day 7, routine MRI showed both symmetric T1 prolongation and T2 slightly shortening in lateral thalami, DWI showed abnormal high signal intensity in bilateral basal ganglion (mainly in the back site of lentiform nuclei, putamen) and the cortex around central sulcus, but the previous hyperintensity in lateral thalami and PLIC disappeared. On day 14, routine MRI showed symmetric T1 prolongation, T2 shortening in bilateral thalami, lentiform nuclei and cortex around central sulus. On day 21, routine MRI showed T1 prolongation, T2 shortening in bilateral thalami and basal ganglion while previously obvious PLIC disappeared, whereas DWI showed normal images. Eight months later, deeper cerebral sulus, dilation of ventricles and widening of extracerebral space were shown.

CONCLUSIONDiffusion-weighted imaging has proved more sensitive than conventional MR imaging sequences in detecting acute cerebral infarction in adult subjects. DWI is proposed as a method for early detection of hypoxic-ischemic brain injury. In this study, DWI showed the same focus (lateral thalami and PLIC) and similar extent of the injury in these severe HIE patients in the early stage after birth (in 72 hours). The sites which showed hyperintensive signals in DWI were consistent with the foci in subsequent follow-up by routine MRI. Thus, DWI is supposed to be a technique for early assessment of the extent of hypoxic-ischemic brain injury and the prognosis in clinic. Though DWI is superior to the other imaging modalities in detecting ischemia, diffusion restriction is not necessarily indicative of permanent damage. The abnormal image on DWI may not last long. However, in chronic stage, the follow-up conventional MRI may compensate the inadequacy of DWI.

Brain ; pathology ; Cerebral Cortex ; metabolism ; Cerebral Infarction ; metabolism ; Diffusion ; Humans ; Hypoxia-Ischemia, Brain ; metabolism ; Infant ; Infant, Newborn ; Magnetic Resonance Imaging ; methods ; Stroke ; metabolism

OBJECTIVETo study the effect of electro-acupuncture (EA) in regulating calcium (Ca2+) content in brain neurocytes of rats with focal cerebral ischemia.

METHODSThe changes of Ca2+ content in ischemic neurocytes were observed by using laser confocal scanning microscope.

RESULTSCa2+ content did not change significantly in cerebral cortex when the brain ischemia occurred for 1 hr, but it raised significantly in striatum neurocytes. Both the Ca2+ contents in striatum and cortex area increased significantly 3 hrs after ischemia occurrence and the content in striatum was higher than that in cortex significantly. Brain Ca2+ content could be reduced significantly after the 3 hrs ischemic brain were treated by EA for 30 min.

CONCLUSIONEA could regulate the content of Ca2+ in the ischemic area of brain, inhibit Ca2+ overload, so as to protect neurons from ischemic injury.

Animals ; Biological Transport, Active ; Brain ; metabolism ; pathology ; Calcium ; metabolism ; Electroacupuncture ; Infarction, Middle Cerebral Artery ; metabolism ; pathology ; Male ; Microscopy, Confocal ; Neurons ; metabolism ; Random Allocation ; Rats ; Rats, Wistar

OBJECTIVETo observe the change of nitric oxide (NO) and expression of nuclear factor-kappa B (NF-kappaB) in the cortex of cerebral infarction rat induced by photochemical reaction, and study the effect of extract from Cornus officinalis (whose main ingredient is iridoid glycoside) in the course of disease.

METHODAfter rats were fed with experimental drugs for 7 days, the model of cerebral infarction was induced. Spectrophotography and immunohistochemistry were used to detect the change of the content of NO, NOS and the expression of NF-kappaB in the cortex.

RESULTCompared with control group, distinct infarction was visible in the model group, and the content of NO, the activity of NOS and the positive cell number of NF-kappaB were increased obviously. Compared with model group, the extract of C. officeinalis decreased the area of infarction, the content of NO, the activity of NOS and the positive cell number of NF-kappaB.

CONCLUSIONThe iridoid glycoside of C. officinalis may have therapeutical effect on cerebral infarction through regulating the content of NO and NF-kappaB.

Animals ; Cerebral Cortex ; metabolism ; pathology ; Cerebral Infarction ; metabolism ; pathology ; Cornus ; chemistry ; Drugs, Chinese Herbal ; isolation & purification ; pharmacology ; Male ; NF-kappa B ; metabolism ; Nitric Oxide ; metabolism ; Nitric Oxide Synthase ; metabolism ; Plants, Medicinal ; chemistry ; Random Allocation ; Rats ; Rats, Sprague-Dawley

The aim of the present study was to assess the clinical and histopathological findings in a canine model of ischemic stroke. Cerebral ischemic stroke was induced by middle cerebral artery occlusion in four healthy beagle dogs using silicone plugs. They showed neurological signs of forebrain dysfunction such as reduced responsiveness, head turning, circling, postural reaction deficits, perceptual deficits, and hemianopsia. These signs gradually regressed within 4 weeks without therapy. On magnetic resonance imaging, T2 hyperintensity and T1 hypointensity were found in the cerebral cortex and basal ganglia. These lesions were well-defined and sharply demarcated from adjacent brain parenchyma with a homogenous appearance. No abnormalities of the cerebrospinal fluid were observed. At necropsy, atrophic and necrotic lesions were observed in the cerebral cortex. The cerebral cortex, basal ganglia, and thalamus were partially unstained with triphenyl-tetrazolium chloride. Histopathologically, typical features of infarction were identified in cortical and thalamic lesions. This study demonstrates that our canine model resembles the conditions of real stroke patients.
Animals ; Behavior, Animal/physiology ; Brain/metabolism/pathology ; Cerebral Infarction/*etiology/*pathology ; Cerebrospinal Fluid/chemistry/cytology ; Disease Models, Animal ; *Dogs ; Infarction, Middle Cerebral Artery/*complications/*pathology ; Magnetic Resonance Imaging ; Male

PURPOSE: This study was done to identify whether pre-conditioning exercise has neuroprotective effects against cerebral ischemia, through enhance brain microvascular integrity. METHODS: Adult male Sprague-Dawley rats were randomly divided into four groups: 1) Normal (n=10); 2) Exercise (n=10); 3) Middle cerebral artery occlusion (MCAo), n=10); 4) Exercise+MCAo (n=10). Both exercise groups ran on a treadmill at a speed of 15 m/min, 30 min/day for 4 weeks, then, MCAo was performed for 90 min. Brain infarction was measured by Nissl staining. Examination of the remaining neuronal cell after MCAo, and microvascular protein expression on the motor cortex, showed the expression of Neuronal Nuclei (NeuN), Vascular endothelial growth factor (VEGF) & laminin. RESULTS: After 48 hr of MCAo, the infarct volume was significantly reduced in the Ex+MCAo group (15.6+/-2.7%) compared to the MCAo group (44.9+/-3.8%) (p<.05), and many neuronal cells were detected in the Ex+MCAo group (70.8+/-3.9%) compared to the MCAo group (43.4+/-5.1%) (p<.05). The immunoreactivity of laminin, as a marker of microvessels and Vascular endothelial growth factor (VEGF) were intensively increased in the Ex+MCAo group compared to the MCAo group. CONCLUSION: These findings suggest that the neuroprotective effects of exercise pre-conditioning reduce ischemic brain injury through strengthening the microvascular integrity after cerebral ischemia.
Animals ; Brain Infarction/pathology ; Disease Models, Animal ; Infarction, Middle Cerebral Artery/metabolism/pathology/*prevention & control ; Laminin/metabolism ; Male ; Microvessels/metabolism ; Neurons/metabolism ; *Physical Conditioning, Animal ; Rats ; Rats, Sprague-Dawley ; Stroke/prevention & control ; Vascular Endothelial Growth Factor A/metabolism

This study is to investigate the effect of gamma-hydroxybutyric acid receptor (GHBR) on focal cerebral ischemia-reperfusion injury in rats and its mechanism. NCS-356 (the agonist of GHBR) and NCS-382 (the antagonist of GHBR) were adopted as the tool medicine. The ripe male Sprague-Dawley rats weighing 240 - 280 g were randomly divided into seven groups: sham operation group (sham), ischemia-reperfusion group (Isc/R), NCS-356 160 microg x kg(-1) group (N1), NCS-356 320 microg x kg(-1) group (N2), NCS-356 640 microg x kg(-1) group (N3), NCS-382 640 microg x kg(-1) + NCS-356 640 microg x kg(-1) group (NCS-382 + N3), and nimodipine (Nim) 600 microg x kg(-1) group. The middle cerebral artery occlusion (MCAO) model referring to Longa's method with modifications was adopted. The effect of GHBR on behavioral consequence of MCAO rats was studied after 2 h of ischemia-reperfusion. After 24 h of ischemia-reperfusion, part of animals were used to measure the cerebral infarction volume by TTC staining; ischemic cortex of another part of animals were used to measure the content of intracellular free calcium by flow cytometry, the tNOS, iNOS activity and the content of NO by spectrophotometric method, the content of cGMP by radioimmunoassay. The neurological function score and infarction volume rate in Isc/R group rats increased significantly than that in sham group; The content of intracellular calcium ([Ca2+]) of cortex neuron and cGMP, the activities of tNOS and iNOS, and the content of NO in Isc/R group were higher than that in sham group obviously (P < 0.01); These consequence we mentioned of N1, N2, N3 and Nim group were lower than that of Isc/R. NCS-382 + N3 group could significantly antagonize the above effect of N3. Thus, NCS-356 has protective effects against ischemia-reperfusion brain injury by activating GHBR. The neuroprotective effect of GHBR is related with decreasing the content of [Ca2+]i, NO, cGMP and tNOS, iNOS activity in MCAO rats.
Animals ; Benzocycloheptenes ; pharmacology ; Calcium ; metabolism ; Cerebral Cortex ; metabolism ; Cerebral Infarction ; pathology ; Cyclic GMP ; metabolism ; Infarction, Middle Cerebral Artery ; complications ; Male ; Neuroprotective Agents ; pharmacology ; Nitric Oxide ; metabolism ; Nitric Oxide Synthase ; metabolism ; Nitric Oxide Synthase Type II ; metabolism ; Random Allocation ; Rats ; Rats, Sprague-Dawley ; Receptors, Cell Surface ; agonists ; antagonists & inhibitors ; metabolism ; Reperfusion Injury ; etiology ; metabolism ; pathology

OBJECTIVE: To explore the expression profile of Ephrin-B2 in the ischemic penumbra after transient focal cerebral ischemia in rats, and to clarify the mechanism of Ephrin-B2 triggering angiogenesis. METHODS: Sprague-Dawley rats were randomly divided into a normal group, a sham operation group and ischemic-reperfusion 1, 3, 7, 14, and 28 d groups. Suture-occluded method was used to establish the focal middle cerebral artery occlusion model and the ischemic brain was reperfused 2 h after the occlusion. Western blot and quantitative real-time reverse-transcription polymerase chain reaction were used to detect the dynamic expression profile of Ephrin-B2 in the penumbra cortex. Double immunofluorescence was used to speculate the location and the co-expression of Ephrin-B2 in blood vessels, neurons and astrocytes. Microvessel density was quantified by the number of CD31+ cells. Rats were subjected to neurologic functional tests by modified neurological severity scores (mNSS) before sacrifice. RESULTS: Compared with the sham group, Ephrin-B2 protein and mRNA level of the penumbra cortex in the ischemic group increased 3 days (P<0.05) after the reperfusion, peaked at day 7 and 14 (P<0.01), and declined at day 28. Double immunofluorescence indicated that Ehprin-b2 was expressed in the neurons, blood vessels and astrocytes; mNSS peaked at day 7, and gradually declined at day 14. The microvessel density of penumbra cortex in the ischemic group increased 3 days (P<0.05) after the reperfusion, peaked at day 14 (P<0.01), and gradually declined at 48 h. CONCLUSION Cerebral ischemia reperfusion induces the over-expression of Ephrin-B2, with a dynamic trend, suggesting that Ehprin-b2 may improve post-stroke functional recovery by enhancing angiogenesis and neurogenesis.
Animals ; Astrocytes ; metabolism ; Brain ; pathology ; Brain Ischemia ; metabolism ; Cerebral Cortex ; metabolism ; Ephrin-B2 ; metabolism ; Infarction, Middle Cerebral Artery ; Ischemic Attack, Transient ; Neurons ; metabolism ; Rats ; Rats, Sprague-Dawley ; Reperfusion Injury ; metabolism

AIMTo study the effects of 1-(2,6-dimethylphenoxy)-2-(3,4-dimethoxyphenylethylamino) propane hydrochloride(DDPH) on brain ischemia injury in rats.

METHODSBy using the middle cerebral artery occlusion (MCAO) induced by nylon surgical thread inserted through the internal carotid artery into the anterior cerebral artery in rats, the effects of DDPH on neuron defects(ND) and infarct size(IS) were investigated. Using incomplete cerebral ischemia in rats, the effects of DDPH on superoxide dismutase (SOD) activity and malondialdehyde (MDA) content in brain tissue and pathological changes in rats were studied.

RESULTSDDPH at the dose of 10 mg.kg-1 i.p. 30 min before ischemia decreased the ND 3 h after ischemia. The IS declined 24 h after ischemia as well. Meanwhile, DDPH was found to increase SOD activity and reduce the MDA content, as well as mitigate pathological damage, of neuron after brain ischemia in rats.

CONCLUSIONDDPH showed protective effects on brain ischemia, probably related to its properties of calcium antagonistic effect and increasing the activity of superoxide dismutases.

Animals ; Brain ; metabolism ; pathology ; Brain Ischemia ; metabolism ; pathology ; Female ; Infarction, Middle Cerebral Artery ; pathology ; Male ; Malondialdehyde ; metabolism ; Neuroprotective Agents ; pharmacology ; Phenethylamines ; pharmacology ; Rats ; Rats, Wistar ; Reperfusion Injury ; metabolism ; pathology ; Superoxide Dismutase ; metabolism