Bilateral Carotid Artery Ligation Research Articles

MORPHOLOGICAL CHANGES IN THE HIPPOCAMPUS OF THE RAT BRAIN IN ISCHEMIA AND IN CONDITIONS OF COMBINED PRECONDITIONING

BACKGROUND: Preconditioning is an effective method of increasing the body's resistance to hypoxia/ischemia.
 AIM: The aim is to evaluate morphological changes in the most hypoxia-sensitive fields of the hippocampus CA1 and CA3 in cerebral ischemia in rats and under conditions of combined preconditioning.
 MATERIALS AND METHODS. Cerebral ischemia was simulated in rats under anesthesia (8% chloral hydrate solution 400 mg/kg) by bilateral ligation of the common carotid arteries. The combined preconditioning method (CPreC) included the alternate use of two preconditional factors – pharmacological (amtisol at a dose of 25 mg /kg) and hypoxic (hypobaric hypoxia, 410 mmHg, exposure time 60 min). Morphometric assessment of brain damage was performed a day after modeling ischemia in the CA1 and CA3 fields of the hippocampus.
 RESULTS. KPreK has a positive effect on the morphometric parameters of the brain during its ischemia, increasing the survival of neurons in the early and late periods of ischemia modeling, preventing the formation of necrotically and apoptotically altered neurons, hyperactivation of microglial cells and contributing to the preservation of endotheliocytes. 
 CONCLUSION. KPreK (amtisol + hypobaric hypoxia) has a neuroprotective effect in cerebral ischemia.

Hydrogen Sulfide Protects against Rat Ischemic Brain Injury by Promoting RhoA Phosphorylation at Serine 188.

The protective role of hydrogen sulfide against cerebral ischemia-reperfusion injury involves the inhibition of the RhoA-/Rho-associated coiled-coil kinase (ROCK) pathway. However, the specific mechanism remains elusive. This study investigates the impact of hydrogen sulfide on RhoA phosphorylation at serine 188 (Ser188) in vivo, aiming to test the hypothesis that hydrogen sulfide exerts neuroprotection by enhancing RhoA phosphorylation at Ser188, subsequently inhibiting the RhoA/ROCK pathway. Recombinant RhoAwild-pEGFP-N1 and RhoAS188A-pEGFP-N1 plasmids were constructed and administered via stereotaxic injection into the rat hippocampus. A rat global cerebral ischemia-reperfusion model was induced by bilateral carotid artery ligation to elucidate the neuroprotective mechanisms of hydrogen sulfide. Both RhoAwild-pEGFP-N1 and RhoAS188A-pEGFP-N1 plasmids expressed RhoAwild and RhoAS188A proteins, respectively, in rat hippocampal tissues, alongside the intrinsic RhoA protein. Systemic administration of the exogenous hydrogen sulfide donor sodium hydrosulfide led to an increase in Ser188 phosphorylation of transfected RhoAwild and intrinsic RhoA protein within the hippocampus. However, this effect was not observed in tissues transfected with RhoAS188A. Sodium hydrosulfide-mediated RhoA phosphorylation correlated with decreased RhoA and ROCK2 activity in rat hippocampal tissues. Furthermore, sodium hydrosulfide administration reduced cerebral ischemia-reperfusion-induced neuronal damage and apoptosis in rat hippocampal tissues transfected with RhoAwild. However, this neuroprotective effect was attenuated in rats transfected with RhoAS188A. These findings suggest that the neuroprotective mechanism of hydrogen sulfide against cerebral ischemia/reperfusion injury involves increased RhoA phosphorylation at Ser188. Promoting this phosphorylation may represent a potential intrinsic therapeutic target for ischemic stroke.

Effect of different combinations of neuroprotectors on neurological deficit, motor and orientation-research activity, cognitive functions during experimental ischemic stroke

Annotation. Today, the maximum efforts of scientists are aimed at preserving the functional capacity and restoring neurons in the ischemic penumbra zone by developing new methods of neuroprotection, one of such approaches could be the combination of different neuroprotectors according to the mechanism of action. The purpose of the study is to study the effect of different combinations of neuroprotectors on neurological deficits, motor and orientation-research activity, and cognitive functions during experimental ischemic stroke. The study was conducted in the modelling of acute stroke according to the ischemic type on non-linear male rats by bilateral ligation of the internal carotid arteries. The four most effective combinations of neuroprotective complexes were selected as neuroprotective complexes (NPC) under investigation: cerebrolysin + mexidol; cerebrolysin + citicoline; cerebrolysin + edaravone; cerebrolysin + choline alfoscerate, which were previously discovered after screening the therapeutic effectiveness of various neuroprotectors and their combinations. Evaluation of the therapeutic effect of NPC was carried out on the 4th and 7th day of therapy. Neurological deficits were assessed using the McGraw Stroke Index. Locomotor and orientation-research activity was determined in the “open field” test. Cognitive functions were investigated in the extrapolation release test. The study of the cerebroprotective properties of four different combinations of neuroprotectors on an experimental model of an ischemic impression of the brain based on indicators of neurological deficit, locomotor and orientation-research activity, and cognitive functions made it possible to identify the most effective combinations and arrange them in order of decreasing effectiveness: NPC № 2 ≥ NPC №1 > NPC №4 ≥ NPC №3.

Rectal temperature after hypoxia-ischemia predicts white matter and cortical pathology in the near-term ferret.

Neonatal encephalopathy (NE) remains a common cause of infant morbidity and mortality. Neuropathological corollaries of NE associated with acute hypoxia-ischemia include a central injury pattern involving the basal ganglia and thalamus, which may interfere with thermoregulatory circuits. Spontaneous hypothermia (SH) occurs in both preclinical models and clinical hypoxic-ischemic NE and may provide an early biomarker of injury severity. To determine whether SH predicts the degree of injury in a ferret model of hypoxic-ischemic NE, we investigated whether rectal temperature (RT) 1 h after insult correlated with long-term outcomes. Postnatal day (P)17 ferrets were presensitized with Escherichia coli lipopolysaccharide before undergoing hypoxia-ischemia/hyperoxia (HIH): bilateral carotid artery ligation, hypoxia-hyperoxia-hypoxia, and right ligation reversal. One hour later, nesting RTs were measured. Animals exposed to HIH were separated into normothermic (NT; ≥34.4 °C) or spontaneously hypothermic (SH; <34.4 °C) groups. At P42, cortical development, ex vivo MRI, and neuropathology were quantitated. Whole-brain volume and fractional anisotropy in SH brains were significantly decreased compared to control and NT animals. SH brains also had significantly altered gyrification, greater cortical pathology, and increased corpus callosum GFAP staining relative to NT and control brains. In near-term-equivalent ferrets, nesting RT 1 h after HIH may predict long-term neuropathological outcomes. High-throughput methods to determine injury severity prior to treatment in animal studies of neonatal brain injury are lacking. In a gyrified animal model of neonatal inflammation-sensitized hypoxic-ischemic brain injury in the ferret, rectal temperature 1 h after hypoxia predicts animals who will have increased cortical pathology and white matter changes on MRI. These changes parallel similar responses in rodents and humans but have not previously been correlated with long-term neuropathological outcomes in gyrified animal models. Endogenous thermoregulatory responses to injury may provide a translational marker of injury severity to help stratify animals to treatment groups or predict outcome in preclinical studies.

Photobiomodulation Promotes Hippocampal Neurogenesis and Improves Cognitive Function and Anti-Inflammatory Injury in Rats With Chronic Cerebral Hypoperfusion

To investigate the effect of photobiomodulation (PBM) on hippocampal neurogenesis, cognitive function, and inflammatory injury in rats with chronic cerebral hypoperfusion. Bilateral ovariectomy (OVX) was performed on female Sprague-Dawley (SD) rats. One week later, the rats were randomly assigned to three groups, Sham surgery (or Sham) group, bilateral common carotid artery occlusion (BCCAO) group, and PBM intervention (or BCCAO+PBM) group. There were 8 rats in each group. In the BCCAO group, chronic cerebral hyporeperfusion was induced by permanent ligation of bilateral common carotid arteries and no PBM was given. Rats in the Sham group underwent the same surgical procedure except for the occlusion of the two carotids arteries and no PBM was given. In addition to the BCCAO surgery, rats in the BCCAO+PBM group received 808 nm laser therapy (5 min each time at a laser dose of 20 mW/cm 2) of the frontal cortex every other day for 1 month. Between 86 and 90 days after BCCAO, Morris water maze (MWM) was used to observe the spatial learning and memory function of the rats. The rats were sacrificed on day 90 and immunofluorescence staining and Western blot were performed thereafter. Immunofluorescence staining was used to determine the expression of 5-bromodeoxyuracil nucleoside (BrdU), a cell proliferation marker, glial fibrillary acidic protein (GFAP), an astrocyte marker, doublecortin (DCX), a specific marker of newborn neuron precursor cells, NeuN, a marker of mature neurons, and Iba1, a microglia marker, in the hippocampal dentate gyrus (DG) region. Western blot was performed to analyze the protein expressions of inflammasome components, NLRP3, ASC, cleaved caspase-1, and Iba1 in the hippocampus. In the latency trial of MWM test, BCCAO+PBM rats spent shorter periods of time finding the underwater platform than the BCCAO rats did. In the probe trial, after the platform that was original placed in a quadrant was removed, the BCCAO+PBM rats spent longer periods of time exploring the quadrant than the BCCAO animals did ( P<0.05). Compared with BCCAO rats, BCCAO+PBM rats showed significant decrease in the immunofluorescence intensities of GFAP and Iba1 ( P<0.01). PBM intervention significantly increased the number of BrdU-positive cells in the hippocampal DG region compared with those of Sham and BCCAO groups ( P<0.05). Furthermore, the number of NeuN positive cells showed no significant difference among the three groups, while in BCCAO+PBM group, the number of DCX-positive cells was significantly increased ( P<0.001) and the number of DCX +/NeuN + co-located cells was significantly increased compared to that of the BCCAO group ( P<0.001). Compared with those of the BCCAO group, Western blot results showed that the protein expression levels of Iba1, NLRP3, and cleaved caspase-1 in the BCCAO+PBM group were significantly decreased ( P<0.05), while the ASC protein expression level showed no significant difference. PBM can effectively improve the spatial learning and memory function in rats with chronic cerebral hypoperfusion, inhibit the activation of glial cells, reduce inflammatory damage mediated by NLRP3 inflammasome, and promote the regeneration of endogenous neural stem cells in the hippocampal DG region of rats.

Effect of moxibustion on inositol requiring enzyme 1 / X-box binding protein 1 pathway in hippocampal CA1 region of rats with vascular dementia

To observe the effect of moxibustion at Governor Vessel acupoints on inositol requiring enzyme 1 （IRE1） / X-box binding protein 1 （XBP1） pathway in hippocampal CA1 region of rats with vascular dementia （VD）, so as to explore its mechanisms in the treatment of VD. Male SD rats were randomly divided into normal, sham operation, model, moxibustion （Moxi） and medication groups （n=12）. The VD model was established by permanent ligation of bilateral common carotid arteries. For rats of the Moxi group, mild moxibustion was given to "Baihui" （GV20）, "Dazhui" （GV14） and "Fengfu" （GV16） for 20 min each point, once a day for consecutive 6 days per week, for a total of 4 weeks. For rats of the medication group, intragastric perfusion of nimodipine was given 3 times each day with total dose of 2 mg•kg-1•d-1 for 4 weeks. Morris water maze test was used to detect the learning and memory ability of rats before and after modeling as well as after intervention. The apoptosis rate of nerve cells in hippocampal CA1 region was detected by TUNEL staining. The proteins and mRNA expression levels of IRE1, XBP1, B-cell lymphoma/leukemia-2 （Bcl-2）, Bcl-2 associated X protein （Bax） in hippocampal CA1 region were detected by Western blot and real-time quantitative PCR, respectively. Compared with the sham operation group, the average escape latency was significantly prolonged （P<0.01）, the number of times crossing the original platform was significantly reduced （P<0.01）, the apoptosis rate of nerve cells in hippocampal CA1 region was significantly increased （P<0.01）, the proteins and mRNA expression levels of IRE1, XBP1 and Bax were significantly increased （P<0.01）, and the expression levels of Bcl-2 protein and mRNA were significantly decreased （P<0.01） in rats of the model group. After treatment, compared with the model group, the average escape latency was significantly shortened （P<0.01）, the number of times crossing the original platform was increased （P<0.05）, the apoptosis rate of nerve cells in hippocampal CA1 region was significantly decreased （P<0.01）, the protein and mRNA expression levels of IRE1, XBP1 and Bax were decreased （P<0.05, P<0.01）, and the expression levels of Bcl-2 protein and mRNA were increased （P<0.05, P<0.01） in rats of the Moxi group and medication group. There was no significant difference in the above indexes between the Moxi group and the medication group. Moxibustion at the acupoints of Governor Vessel can improve the cognitive function of VD rats, and its mechanism may be related to regulating IRE1/XBP1 pathway, inhibiting the release of pro-apoptotic protein Bax, increasing the expression of anti-apoptotic protein Bcl-2, and thus inhibiting the apoptosis of hippocampal nerve cells.

Sub-dose anesthetics combined with chloride regulators protect the brain against chronic ischemia-hypoxia injury.

Cerebral ischemia-hypoxia leads to excitotoxicity-mediated neuronal damage and cognitive dysfunction, especially in the elderly. Excessive intracellular [Cl- ]i accumulation weakens γ-aminobutyric acid (GABA) compensatory effects. Sub-anesthetic dose of propofol protected the brain against ischemia-hypoxia, which was abolished by blocking Cl- efflux transporter K+ /Cl- cotransporter 2 (KCC2). We aimed to determine whether low-dose anesthetic combined with [Cl- ]i regulators could restore the compensatory GABAergic system and improve cognitive function. Chronic cerebral hypoxia (CCH) model was established by bilateral carotid artery ligation in aged rats. Sub-dose of anesthetics (propofol and sevoflurane) with or without KCC2 agonist N-ethylmaleimide (NEM) or Na+ /K+ /Cl- cotransporter 1 (NKCC1) antagonist bumetanide (BTN) was administered systemically 30 days post-surgery. Primary rat hippocampal neuronal cultures were subjected to hypoxic injury with or without drug treatment. Memory function, hippocampal neuronal survival, GABAergic system functioning, and brain-derived neurotrophic factor (BDNF) expressions were evaluated. Sub-anesthetic dose of combined propofol (1.2 μg mL-1 ) and sevoflurane [0.7 MAC (minimum alveolar concentration)] did not aggravate the hypoxic brain injury in rats or cell damage in neuronal cultures. Adding either BTN or NEM protected against hypoxic injury, associated with improved cognitive function in vivo, less intracellular accumulation of [Cl- ]i , reduced cell death, restored GABAergic compensation, and increased BDNF expression both in vivo and in vitro. Sub-anesthetic dose of propofol and sevoflurane is a recommended anesthesia regimen in at-risk patients. Restoration of [Cl- ]i homeostasis and GABAergic could further reduce the brain damage caused by ischemia-hypoxia.

Vasoactive and Neuroprotective Action of с-Jun-N-Terminal Kinases Inhibitor in Rats with Chronic Brain Hypoperfusion

The aim of this study was to evaluate the vasoactive and neuroprotective effects of c-Jun-N-terminal kinase inhibitor IQ-1 (11H-indeno[1,2-b]quinoxalin-11-one oxime) in chronic cerebral hypoperfusion caused by irreversible bilateral ligation of carotid arteries. Cerebral blood flow was measured quantitatively (hydrogen clearance method) simultaneously in the parietal cortex, hippocampus, substantia nigra, and striatum of the brain of awake rats. It was found that ligation of the carotid arteries caused a decrease in blood flow in the brain structures with a more pronounced decrease in the cortex (by 48% of the initial level) and with the smallest drop in the substantia nigra (by 25% of the initial level). The reduced level of blood flow persisted for 14 days of measurements. The responses of the cerebral vessels to hypercapnic probes (5% CO2) were lost during the 2-week hypoperfusion period, and the neurological status of the animals did not improve. The administration of IQ-1 (50 mg/kg, intraperitoneally, every 48 hours for 14 days) was accompanied by an increase in blood flow in all brain structures. The maximum increase in blood flow was observed in the striatum and the minimum in the substantia nigra. After the administration of IQ-1, the sensitivity of the cerebral vessels to the hypercapnic stimulus was restored and the neurological state of the animals significantly improved by the end of the second week of cerebral hypoperfusion. The results show that the use of the JNK inhibitor can reduce cerebrovascular disorders and associated neurological disorders in hypoperfusion brain injury.

Untargeted metabolomics uncovering neuroprotective effect of Dl-3-n-butylphthalide on improving cognitive impairment induced by chronic cerebral hypoperfusion in rats

Chronic cerebral hypoperfusion (CCH) can cause cognitive impairments. Dl-3-n-butylphthalide (NBP) is widely used in neurological disorders; but, the role of NBP in CCH remains unclear. This study aimed to investigate the potential mechanism of NBP on CCH through untargeted metabolomics. Animals were divided into CCH, Sham, and NBP groups. A rat model of bilateral carotid artery ligation was used to simulate CCH. Cognitive function of the rats was assessed using the Morris water maze test. Additionally, we used LC-MS/MS to detect ionic intensities of metabolites between the three groups for off-target metabolism analysis and to screen for differential metabolites. The analysis showed an improvement in cognitive function in rats after NBP treatment. Moreover, metabolomic studies showed that the serum metabolic profiles of the Sham and CCH groups were significantly altered, and 33 metabolites were identified as potential biomarkers associated with the effects of NBP. These metabolites were enriched in 24 metabolic pathways.And the pathway of differential metabolite enrichment was further verified by immunofluorescence. Thus, the study provides a theoretical basis for the pathogenesis of CCH and the treatment of CCH by NBP, and supports a wider application of NBP drugs.

Changes In the Morphology of Neurons of The Parietal Cortex and Hippocampus of Rats in The Dynamics of Step Subtotal Cerebral Ischemia

The study of the brain in norm and pathology is an urgent and promising direction of modern science and, in this regard, a frequent topic of dissertation research. Cerebral ischemia leads to a number of general and local metabolic and functional disorders, the pathogenesis of which is complex, multifaceted and largely. The aim was to change the morphology of neurons in the parietal cortex and hippocampus of rats in the dynamics of stepwise subtotal cerebral ischemia. With stepwise bilateral ligation of both common carotid arteries with an interval of 7 days, negative changes were least pronounced, especially in the hippocampus. The longer the interval between dressings, the more effectively neurons adapt to lack of oxygen, which makes it possible to further study in more detail the dynamics of the mechanisms of damage development and adaptive changes in the brain.

Dendrobium Nobile Polysaccharides Attenuates Ferroptosis and Improves Cognitive Function in Vascular Dementia Rats.

To investigate the neuroprotective effect and mechanism of Dendrobium nobile polysaccharide (DNP) on vascular dementia (VD) rats. VD model rats were prepared by permanent ligation of bilateral common carotid arteries. Cognitive function was tested by morris water maze test, mitochondrial morphology and ultrastructure of hippocampal synapses were tested by transmission electron microscopy, GSH, xCT, GPx4, and PSD-95 expressions were tested by western blot and PCR. The number of platform crossing was significantly increased, and the escape latency was significantly shorter in DNP group. The expressions of GSH, xCT and GPx4 in the hippocampus were up-regulated in DNP group. Moreover, the synapses of DNP group were relatively intact and synaptic vesicles increased, the length of synaptic active zone and PSD thickness were significantly increased, and PSD-95 protein expression was significantly up-regulated compared VD group. DNP may take a neuroprotective effect by inhibiting ferroptosis in VD.

Effects of perindopril on the swallowing reflex in a rat dysphagia model induced by ligation of bilateral common carotid arteries (BCAO)

Effects of perindopril on the swallowing reflex in a rat dysphagia model induced by ligation of bilateral common carotid arteries (BCAO)

Combination of indirect revascularization and endothelial progenitor cell transplantation improved cerebral perfusion and ameliorated tauopathy in a rat model of bilateral ICA ligation

ObjectiveEndothelial progenitor cells (EPCs) contribute to the recovery of neurological function after ischemic stroke. Indirect revascularization has exhibited promising effects in the treatment of cerebral ischemia related to moyamoya disease and intracranial atherosclerotic disease. The role of EPCs in augmenting the revascularization effect is not clear. In this study, we investigated the therapeutic effects of indirect revascularization combined with EPC transplantation in rats with chronic cerebral ischemia.MethodsChronic cerebral ischemia was induced by bilateral internal carotid artery ligation (BICAL) in rats, and indirect revascularization by encephalo-myo-synangiosis (EMS) was performed 1 week later. During the EMS procedure, intramuscular injection of EPCs and the addition of stromal cell-derived factor 1 (SDF-1), and AMD3100, an SDF-1 inhibitor, were undertaken, respectively, to investigate their effects on indirect revascularization. Two weeks later, the cortical microcirculation, neuronal damage, and functional outcome were evaluated according to the microvasculature density and partial pressure of brain tissue oxygen (PbtO2), regional blood flow, expression of phosphorylated Tau (pTau), TUNEL staining and the rotarod performance test, respectively.ResultsThe cortical microcirculation, according to PbtO2 and regional blood flow, was impaired 3 weeks after BICAL. These impairments were improved by the EMS procedure. The regional blood flow was further increased by the addition of SDF-1 and decreased by the addition of AMD3100. Intramuscular injection of EPCs further increased the regional blood flow as compared with the EMS group. The rotarod test results showed that the functional outcome was best in the EMS combined with EPC injection group. Western blot analysis showed that the EMS combined with EPC treatment group had significantly decreased expressions of phosphorylated Tau and phosphorylated glycogen synthase kinase 3 beta (Y216 of GSK-3β). pTau and TUNEL-positive cells were markedly increased at 3 weeks after BICAL induction. Furthermore, the groups treated with EMS combined with SDF-1 or EPCs exhibited marked decreases in the pTau expression and TUNEL-positive cells, whereas AMD3100 treatment increased TUNEL-positive cells.ConclusionThe results of this study suggested that indirect revascularization ameliorated the cerebral ischemic changes. EPCs played a key role in augmenting the effect of indirect revascularization in the treatment of chronic cerebral ischemia.

Influence of physical loading on behavioral reactions of rats in cerebral hypoperfusion

A number of clinical studies demonstrate that individual characteristics such as stress tolerance and cognitive ability can be considered not only as diagnostic variables but also as risk factors for severe cerebral hypoperfusion. The aim of the study was to identify the typological features of the effect of physical activity on the behavioral reactions of rats during cerebral hypoperfusion. Material and methods. Cerebral hypoperfusion was modeled by bilateral carotid artery ligation. The study involved 280 rats, divided into equal subgroups, according to sex, stress tolerance and learning capacity. Of these, 112 animals were subjected to daily short-term swimming as a rehabilitation model. Before the simulation, and at 6, 8, 14, 21, 28, 35, 60 and 90 days postoperatively, the animals were tested using a Morris water maze and an “open field” test. Results and discussion. The dynamics of stress resistance and learning ability are related to the periodicity of inflammatory, necrotic, circulatory and reparative remodeling in the model used. After 2-3 months of study, cerebral hypoperfusion causes stabilization of indices characterizing stress resistance and cognitive functions below control values. A decrease in stress resistance begins earlier from day 6 of the study, while the index characterizing cognitive functions first decreases significantly after 3 weeks of study. Factors reducing the damaging effects of cerebral hypoperfusion were female gender, high baseline stress tolerance and learning ability. When assessing learning ability under physical load, animals with high baseline cognitive development showed earlier recovery dynamics during urgent adaptation and a significant increase during long-term adaptation.

Comparison of the immunohistochemical and ultrastructural studies of the white rats sensorimotor cortex synaptic terminals reaction to common carotid arteries ligation

The aim of the research was to study the structural and functional changes in axonal terminals in layers I, III, and V of the sensorimotor cortex (SMC) of the brain of Wistar rats after the common carotid artery (CCA) bilateral ligation using immunohistochemical and apparatus-microscopic methods. Material and methods. Incomplete cerebral ischemia was modeled by bilateral ligation of the common carotid arteries (CCA - 2-vessel model of global ischemia without hypotension) in white Wistar rats (n=36). SMC was studied in the control (intact rats, n=6), 1, 3, 7, 14 and 30 days (n=30) after POCA. Nissl, hematoxylin-eosin, immunohistochemical reactions for p38, and electron microscopy were used. The total number density and relative area of axonal terminals were determined. Statistical hypotheses were tested using nonparametric methods for pairwise and multiple comparisons using the Statistica 8.0 program. Results. After CCA bilateral ligation, the content of degeneratively altered neurons in the rat brain SMC increased. Changes in the SMC neurons were accompanied by neuropil hyperhydration and reactive astrogliosis. The total number density of terminals in all SMC layers decreased statistically significantly after 1 day (by 28.6% in layer I, 46.9% in layer III, and 46.4% in layer V) and remained approximately at this level throughout the entire observation period. . The relative area of synaptic terminals differed in the compared SMC layers. In layers I and III of the SMC, the values of this indicator first (days 1 and 3) decreased, and then (days 7, 14, and 30) they increased. In layer V of the SMC, activation of the expression of this protein occurred already in the acute period (days 1 and 3), decreased after 7 and 14 days, and increased again after 30 days. Ultrastructural examination revealed more small terminal axonal branches. However, the general trend of changes in the number of terminals was similar. Conclusion. After CCA bilateral ligation, destructive and compensatory-restorative changes in axonal terminals were revealed in layers I, III, and V of the rat MMC. The reorganization of interneuronal relationships occurred against the background of pronounced manifestations of neuropil hyperhydration. The maximum destruction of synaptic terminals was noted in layer III of the SMC, and their adaptive changes were observed in layer V. The results of immunohistochemical and ultrastructural studies are comparable and complement each other. All this can probably be considered as a structural basis for changes in the integrative-starting activity of the brain after CCA bilateral ligation.

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

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

The nNOS and NeuN expression aspects in the cerebral cortex of rats with different cognitive abilities in cerebral hypoperfusion with short-term physical exercise

Introduction. Physical activity is often used in rehabilitation to restore cognitive function after cerebral blood flow impairment and typological features like baseline cognitive ability may alter their effectiveness.The aim was to evaluate the expression of nNOS and NeuN in the large hemisphere cortex in the cerebral hypoperfusion occurrence in rats having different scores in the Morris maze.Materials and methods. Cerebral hypoperfusion was simulated by bilateral ligation of the common carotid arteries. Before surgery, Wistar rats were divided into equal subgroups with high (HCA) and low levels of cognitive ability (LCA) according to the results of Morris maze testing. Animals were removed from the experiment at 8, 21, 35, 60, and 90 days after surgery, a total of 184 rats, 24 formed the control group and 80 formed the cerebral hypoperfusion subgroup with 80 animals undergoing short-term swimming daily starting on day 7 of the experiment.Results. We revealed the earlier changes in HCA animals (8th day of the experiment) induced by cerebral hypoperfusion accompanied by a more intense nNOS-positive neurons density reduction to 47 % of control values, the length of their processes, and an increase in pericarion area. In LCA the decrease of density was only 75 % of control values and pericarion area does not differ from control values. At later periods on the 60 and 90 days of the experiment LCA demonstrates the preservation of the neurons density and greater length of their processes (67 % of the control subgroup values).Conclusion. HCA is a risk factor for damage of nNOS-positive neurons in cerebral hypoperfusion. Physical exercise more effectively decreases nNOS expression in animals with HCA, which may be one of the sanogenetic mechanisms of this factor.

Effects of electroacupuncture on ROS-NLRP3 inflammatory pathway and autophagy related proteins in hippocampus of vascular dementia rats

To observe the effect of electroacupuncture (EA) on learning-memory ability, ultrastructural changes of hippocampal CA1 neurons, reactive oxygen species (ROS) level, Nod-like receptor protein 3 (NLRP3) and auto-phagy-related proteins expression in the hippocampus of vascular dementia (VD) rats, so as to reveal its partial mechanisms in treating VD. Male SD rats were randomly divided into sham operation, model, and EA groups (n=10 rats in each group). The VD model was established by permanent ligation of bilateral common carotid arteries. Rats of the EA group were treated with EA at "Baihui" (GV20), "Dazhui" (GV14) and bilateral "Shenshu" (BL23) for 30 min, once a day for 4 weeks. Morris water maze was used to evaluate the learning and memory ability of rats before modeling, 4 weeks after modeling and after intervention. Transmission electron microscopy (TEM) was used to observe the ultrastructural changes of hippocampal CA1 neurons. The level of ROS in hippocampus was detected by DCFH-DA fluorescence probe. The expressions of NLRP3, autophagy-related protein Beclin1 and microtubule-associated protein 1 light chain 3 (LC3) were measured by Western blot. In comparison with the sham operation group, the average escape latency of rats in the model group was prolonged (P<0.01), and the times of crossing the original platform were reduced (P<0.05), the level of ROS, the expression levels of LC3-Ⅱ/LC3-Ⅰ ratio, Beclin1 and NLRP3 proteins in hippocampus were increased (P<0.01, P<0.05) in the model group. After EA intervention, the average escape latency of rats was significantly shortened (P<0.01), and the times of crossing the original platform were increased (P<0.05), the level of ROS, the expression levels of LC3-Ⅱ/LC3-Ⅰ ratio, Beclin1 and NLRP3 proteins in hippocampus were decreased (P<0.01, P<0.05) in the EA group compared with those of the model group. Outcomes of TEM showed that CA1 neurons in the hippocampus were damaged, chromatin aggregation, mitochondria pyknosis, cristae structure disorder, rough endoplasmic reticulum expanded and degranulated, the number of free ribosomes decreased, and autophagy could be seen in the model group, which were milder in the EA group. EA at GV20, GV14 and BL23 can improve the learning and memory abilities of VD rats, alleviate the ultrastructural damage of neurons in hippocampal CA1 area, and repair the damaged neurons. The mechanism may be related to the reduction of ROS level, LC3-Ⅱ/LC3-Ⅰ ratio, NLRP3 and Beclin1 protein expression, the decrease of neuronal autophagy, inhibition of activation of NLRP3 inflammasome and alleviation of central inflammatory response.

Morphological and morphometric description of neurons in the sensorimotor cortex of the rat brain after ligation of the common carotid arteries

The aim of the study was to present structural and morphometric changes in the sensorimotor cortex neurons of the rat brain after ligation of the common carotid arteries (LCCA).Material and methods. Cerebral ischemia was modeled in white Wistar rats by irreversible bilateral ligation of common carotid arteries (2-vessel model of incomplete global ischemia, without hypotension). For morphological studies, histological (hematoxylin–eosin, thionin staining according to the Nissl method), immunohistochemical (NSE, GFAP) and morphometric methods were used. The control group consisted of intact animals (n=6), the material was taken 1, 3, 7, 14 and 30 days after the experimental modeling of LCCA (n=30). Morphometric analysis was performed on preparations of frontal sections of the brain using the ImageJ 1.53; statistical hypotheses were tested using the Statistica 8.0.Results. It was found that the number density of normochromic neurons decreased throughout the study period and reached its minimum values 30 days after LCCA: the decrease in layer III was 75.9%, and in layer V it was 72.6%. There was a decrease in the total number density of neurons. After 1 and 3 days, in layers III and V, the content of hyperchromic neurons with intact shape of perikarya increased. The numerical density of hyperchromic neurons with a spindle-shaped perikaryon, a deformed nucleus, as well as neurons with a homogeneous cytoplasm had maximum values after 30 days.Conclusion. After irreversible bilateral LCCA, together with an increase in the number density of hyperchromic pycnotic neurons, as well as neurons with homogenization of the cytoplasm and nucleus, a decrease in the NSE content in the cytoplasm of pyramidal neurons was noted, which may indicate a decrease in the expression of this protein and a decrease in the functional activity of neurons by the end of the study period. An increase in hyperchromic pycnotic neurons and shadow cells against the background of a decrease in the number density of normochromic and hyperchromic non-pycnotic neurons may indicate a significant severity of the processes occurring after LCCA and the irreversibility of destructive changes in nerve cells.

Neurological Deficit and Corrective Effect of Omega-3 Polyunsaturated Fatty Acids in Cerebral Ischemia in Rats: A case-control study

Objectives: It was to assess vasoprotective effects of ω-3 polyunsaturated fatty acids in cerebral ischemia. Materials and methods: The experiments were carried out on 42 male outbred white rats weighing 260 ± 20 g. modeling of cerebral ischemia was carried out under conditions of intravenous thiopental anesthesia (40-50 mg / kg). The studies used models of subtotal, partial and stepwise subtotal cerebral ischemia. The table shows the experimental groups and the number of animals in them. Subtotal cerebral ischemia (SCI) was modeled by simultaneous ligation of both common carotid arteries (CCA). Partial cerebral ischemia (PCI) was modeled by ligating one CCA on the right. Stepwise subtotal CI (SSCI) was performed by sequential ligation of both CCA with an interval of 1 day (subgroup 1), 3 days (subgroup 2), or 7 days (subgroup 3). To study the effects of omega-3 polyunsaturated fatty acids (ω-3 PUFA), animals with CI were injected intragastrically with the drug "Omegamed" (SCI+ω-3 PUFA) at a dose of 5 g / kg body weight for a week. The control group consisted of sham-operated rats of the same sex and weight. Neurological deficits were assessed in the "muscle strength", "swimming test" and "open field" tests after 5-6 hours of the ischemic period. The study was carried out 6 hours after the simulation of the CI. Quantitative continuous data were obtained, which were processed using the licensed computer program Statistica 10.0 for Windows (StatSoft, Inc., USA). Since the experiment used small samples that had an abnormal distribution, the analysis was carried out by methods of nonparametric statistics. Data are presented as Me (LQ; UQ), where Me is the median, LQ is the value of the lower quartile; UQ is the upper quartile value. Differences between groups were considered significant at p &lt;0.05 (Regression Model). Results: With a stepwise bilateral ligation of both common carotid arteries with an interval of 1 day, neurological disorders were most pronounced, which indicates an aggravation of neurological deficit with a reduction in the time between CCA dressings. In rats with SCI, the changes were more pronounced than with PCI, but less than with SCI. The least pronounced changes were noted in the 3rd subgroup (the interval between CCA dressings was 7 days). Studies have shown the dependence of the severity of brain damage in SSCI on the interval between the cessation of blood flow in both CCA. At a 7-day interval between CCA dressings, compensatory mechanisms were activated, which prevented the development of morphological changes and neurological deficits. When CCA was ligated with an interval of 1 day, the degree of neurological deficit was maximal, which indicates insufficient implementation of compensatory mechanisms. Compared with the control group, the rats of the "SCI+ω3-PUFA" group retained neurological deficit, the muscle strength indicator was 86% less (p&lt;0.05), the swimming duration - by 63% (p&lt;0.05), the number of crossed squares - by 55% (p&lt;0.05), the number of washes - by 62% (p&lt;0.05), the number of racks - by 62.5% (p&lt;0.05) and the number of bowel movements - by 60% (p&lt;0.05). However, in comparison with the SCI group, the neurological deficit was less pronounced. There was an increase in muscle strength by 67% (p&lt;0.05), swimming duration by 37.5% (p&lt;0.05) and the number of squares crossed in the open field test by 31% (p&lt;0.05), which indicates the presence of a corrective action in the ω-3 polyunsaturated fatty acids preparation. Conclusion: The introduction of the preparation of ω-3 polyunsaturated fatty acids has a corrective effect in conditions of subtotal cerebral ischemia, contributing to a lesser severity of manifestations of neurological deficit (an increase in muscle strength, duration of swimming and the number of squares crossed in the open field test).