scholarly journals Neurodegeneration, Myelin Loss and Glial Response in the Three-Vessel Global Ischemia Model in Rat

2020 ◽  
Vol 21 (17) ◽  
pp. 6246
Author(s):  
Tatiana Anan’ina ◽  
Alena Kisel ◽  
Marina Kudabaeva ◽  
Galina Chernysheva ◽  
Vera Smolyakova ◽  
...  

(1) Background: Although myelin disruption is an integral part of ischemic brain injury, it is rarely the subject of research, particularly in animal models. This study assessed for the first time, myelin and oligodendrocyte loss in a three-vessel model of global cerebral ischemia (GCI), which causes hippocampal damage. In addition, we investigated the relationships between demyelination and changes in microglia and astrocytes, as well as oligodendrogenesis in the hippocampus; (2) Methods: Adult male Wistar rats (n = 15) underwent complete interruption of cerebral blood flow for 7 min by ligation of the major arteries supplying the brain or sham-operation. At 10 and 30 days after the surgery, brain slices were stained for neurodegeneration with Fluoro-Jade C and immunohistochemically to assess myelin content (MBP+ percentage of total area), oligodendrocyte (CNP+ cells) and neuronal (NeuN+ cells) loss, neuroinflammation (Iba1+ cells), astrogliosis (GFAP+ cells) and oligodendrogenesis (NG2+ cells); (3) Results: 10 days after GCI significant myelin and oligodendrocyte loss was found only in the stratum oriens and stratum pyramidale. By the 30th day, demyelination in these hippocampal layers intensified and affected the substratum radiatum. In addition to myelin damage, activation and an increase in the number of microglia and astrocytes in the corresponding layers, a loss of the CA1 pyramidal neurons, and neurodegeneration in the neocortex and thalamus was observed. At a 10-day time point, we observed rod-shaped microglia in the substratum radiatum. Parallel with ongoing myelin loss on the 30th day after ischemia, we found significant oligodendrogenesis in demyelinated hippocampal layers; (4) Conclusions: Our study showed that GCI-simulating cardiac arrest in humans—causes not only the loss of pyramidal neurons in the CA1 field, but also the myelin loss of adjacent layers of the hippocampus.

Stroke ◽  
2014 ◽  
Vol 45 (suppl_1) ◽  
Author(s):  
Wei Yang ◽  
Huaxin Sheng ◽  
Will Thompson ◽  
Shengli Zhao ◽  
Liangli Wang ◽  
...  

Background and Purpose: Small ubiquitin-like modifier (SUMO) conjugation modulates many key cellular processes. Transient cerebral ischemia dramatically activates SUMO2/3 conjugation, and this is believed to be a protective stress response. It is, therefore, of tremendous clinical interest to characterize the SUMO-modified proteome regulated by transient ischemia. We generated a novel SUMO transgenic mouse and performed the first SUMO proteomics study using post-ischemic brain samples. Methods: CAG-loxP-STOP-loxP-SUMO (CAG-SUMO) mice were generated in which His-SUMO1, HA-SUMO2, and FLAG-SUMO3 were expressed from a single multicistronic transgene in a Cre-dependent manner. CAG-SUMO mice were mated with Emx1 Cre/Cre mice to generate double transgenic CAG-SUMO/Emx1-Cre mice as experimental mice and Emx1 Cre/+ mice as control mice. Double transgenic mice were subjected to 10 min global cerebral ischemia followed by 1 h reperfusion or sham operation. FLAG-SUMO3-conjugated proteins were enriched from cortical tissues and analyzed. Results: Characterization of double transgenic mice demonstrated that exogenous expressed tagged SUMO paralogues were functionally intact and did not perturb the endogenous SUMOylation machinery in the brain. FLAG pulldown of cortical samples from sham and ischemia mice followed by GeLC-MS/MS analysis identified 91 candidates whose SUMOylation states were up-regulated in ischemic samples. Data analysis revealed several potentially important processes in which SUMO3 conjugation may play a key role during ischemia/reperfusion, including the cross-talk between SUMOylation and ubiquitination, glucocorticoid receptor signaling, and modulation of posttranscriptional mRNA processing. Conclusions: SUMO proteomic analysis identified important processes and pathways modulated by SUMOylation in the post-ischemic brain that warrant future investigations, since they could be the key to understand the overall impact of SUMOylation on the fate and functions of post-ischemic neurons. The conditional SUMO transgenic mouse will be an invaluable tool for in-depth in vivo analysis of the SUMO-modified proteome in various pathological states.


2021 ◽  
Vol 22 (11) ◽  
pp. 5883
Author(s):  
Ilia G. Komoltsev ◽  
Stepan O. Frankevich ◽  
Natalia I. Shirobokova ◽  
Aleksandra A. Volkova ◽  
Mikhail V. Onufriev ◽  
...  

Hippocampal damage after traumatic brain injury (TBI) is associated with late posttraumatic conditions, such as depression, cognitive decline and epilepsy. Mechanisms of selective hippocampal damage after TBI are not well understood. In this study, using rat TBI model (lateral fluid percussion cortical injury), we assessed potential association of immediate posttraumatic seizures and changes in corticosterone (CS) levels with neuroinflammation and neuronal cell loss in the hippocampus. Indices of distant hippocampal damage (neurodegeneration and neuroinflammation) were assessed using histological analysis (Nissl staining, Iba-1 immunohistochemical staining) and ELISA (IL-1β and CS) 1, 3, 7 and 14 days after TBI or sham operation in male Wistar rats (n = 146). IL-1β was elevated only in the ipsilateral hippocampus on day 1 after trauma. CS peak was detected on day 3 in blood, the ipsilateral and contralateral hippocampus. Neuronal cell loss in the hippocampus was demonstrated bilaterally; in the ipsilateral hippocampus it started earlier than in the contralateral. Microglial activation was evident in the hippocampus bilaterally on day 7 after TBI. The duration of immediate seizures correlated with CS elevation, levels of IL-1β and neuronal loss in the hippocampus. The data suggest potential association of immediate post-traumatic seizures with CS-dependent neuroinflammation-mediated distant hippocampal damage.


2004 ◽  
Vol 47 (4) ◽  
pp. 285-288 ◽  
Author(s):  
Viera Danielisová ◽  
Miroslava Némethová ◽  
Jozef Burda

Preconditioning of the brain by short-term ischemia increases brain tolerance to the subsequent severer ischemia. In this study, we investigated iron deposition in the cerebral cortex and the ischemic tolerance in a rat model of cerebral ischemia. Forebrain ischemia was induced by four-vessel occlusion for 5 min as ischemic preconditioning. Two days after preconditioning or after the sham-operation, the second ischemia was induced for 20 min. Changes in the cerebral cortex were examined after 1 to 8 weeks of recirculation following 20 min ischemia with or without preconditioning using the iron histochemistry. Granular deposits of the iron were found in the cytoplasm of the pyramidal cells in the layers III and V of the frontal cortex after 1 week of recirculation. When the rats were exposed to 5 min ischemia 2 days before 20 min lasting ischemia, the deposition of iron in the cytoplasm of the pyramidal cells in layers III and V of the frontal cortex was significantly lower during all periods of reperfusion. Preconditioning 5 min ischemia followed by 2 days of reperfusion before 20 min ischemia also prevented degeneration of the pyramidal neurons in layers III and V of the frontal cortex.


1999 ◽  
Vol 82 (3) ◽  
pp. 1615-1621 ◽  
Author(s):  
Srdjan Antic ◽  
Guy Major ◽  
Dejan Zecevic

Understanding the biophysical properties of single neurons and how they process information is fundamental to understanding how the brain works. A technique that would allow recording of temporal and spatial dynamics of electrical activity in neuronal processes with adequate resolution would facilitate further research. Here, we report on the application of optical recording of membrane potential transients at many sites on neuronal processes of vertebrate neurons in brain slices using intracellular voltage-sensitive dyes. We obtained evidence that 1) loading the neurons with voltage-sensitive dye using patch electrodes is possible without contamination of the extracellular environment; 2) brain slices do not show any autofluorescence at the excitation/emission wavelengths used; 3) pharmacological effects of the dye were completely reversible; 4) the level of photodynamic damage already allows meaningful measurements and could be reduced further; 5) the sensitivity of the dye was comparable to that reported for invertebrate neurons; 6) the dye spread ∼500 μm into distal processes within 2 h incubation period. This distance should increase with longer incubation; 7) the optically recorded action potential signals from basolateral dendrites (that are difficult or impossible to approach by patch electrodes) and apical dendrites show that both direct soma stimulation and synaptic stimulation triggered action potentials that originated near the soma. The spikes backpropagated into both basolateral dendrites and apical processes; the propagation was somewhat faster in the apical dendrites.


1982 ◽  
Vol 56 (4) ◽  
pp. 482-497 ◽  
Author(s):  
Jens Astrup

✓ The energy-requiring cell functions in the brain are described. The role of specific inhibition of these functions, and their critical low-supply levels of blood flow and oxygen are reviewed in relation to clinical management of focal and complete global cerebral ischemia.


2019 ◽  
Vol 18 (4) ◽  
pp. 58-64
Author(s):  
N. S. Shcherbak ◽  
A. G. Gurbo ◽  
G. Yu. Yukina ◽  
V. V. Thomson ◽  
E. V. Shlyakhto

Introduction. Ischemic postconditioning (IPostC) of the brain can be considered as a promising approach to limit reperfusion injury in the ischemic area of the brain. Objective – to study the effect of IPostC after global cerebral ischemia on the level of immunoreactivity to PECAM-1/CD31 in the structures of layers II, III and V of the neocortex of rats at different periods of the reperfusion period.Material and methods. In male Wistar rats, a 10-minute global cerebral ischemia was modeled followed by IPostC in the form of reperfusion-ischemia at 15sec/15sec. In the early (2 days) and late (7 days) reperfusion periods after damaging ischemia, the number of morphologically unchanged neurons and the level of immunoreactivity to PECAM-1/CD31 in the structures of layers II, III and V of the neocortex were estimated.Results. It is shown that the use of IPostC by 2 days of reperfusion contributed to the increase in the number of unchanged neurons in layers II and III of 25.8 and 28.2 % (P<0.05), which was not accompanied by changes in the level of immunoreactivity to PECAM-1/CD31, to 7 days of reperfusion there was an increase in the number of unchanged neurons in layers II, III and V of 19.2, 22,1, 21,4 % (P<0.05) was observed a decrease in the level of immunoreactivity to PECAM-1/CD31 in the structures of these layers of 27.4, 39.4, and 16.7 % (P<0.05), respectively, when compared with similar indicators in groups without the use of IPostC.Conlusions. In the mechanisms of physiological reaction formed in the application of ischemic postconditioning after cerebral ischemia and leading to the preservation of the number of unchanged neurons in the late reperfusion period involved PECAM-1/CD31, which suggests that the protective potential of the phenomenon is realized by possible inhibiting the migration of neutrophils, monocytes and lymphocytes and extravasation of leukocytes from the systemic blood flow into the damaged area of the brain, i.e. through suppression of inflammatory response.


Author(s):  
Zafer Sahin ◽  
Alpaslan Ozkurkculer ◽  
Omer Faruk Kalkan ◽  
Ahmet Ozkaya ◽  
Aynur Koc ◽  
...  

Abstract. Alterations of essential elements in the brain are associated with the pathophysiology of many neuropsychiatric disorders. It is known that chronic/overwhelming stress may cause some anxiety and/or depression. We aimed to investigate the effects of two different chronic immobilization stress protocols on anxiety-related behaviors and brain minerals. Adult male Wistar rats were divided into 3 groups as follows ( n = 10/group): control, immobilization stress-1 (45 minutes daily for 7-day) and immobilization stress-2 (45 minutes twice a day for 7-day). Stress-related behaviors were evaluated by open field test and forced swimming test. In the immobilization stress-1 and immobilization stress-2 groups, percentage of time spent in the central area (6.38 ± 0.41% and 6.28 ± 1.03% respectively, p < 0.05) and rearing frequency (2.75 ± 0.41 and 3.85 ± 0.46, p < 0.01 and p < 0.05, respectively) were lower, latency to center area (49.11 ± 5.87 s and 44.92 ± 8.04 s, p < 0.01 and p < 0.01, respectively), were higher than the control group (8.65 ± 0.49%, 5.37 ± 0.44 and 15.3 ± 3.32 s, respectively). In the immobilization stress-1 group, zinc (12.65 ± 0.1 ppm, p < 0.001), magnesium (170.4 ± 1.7 ppm, p < 0.005) and phosphate (2.76 ± 0.1 ppm, p < 0.05) levels were lower than the control group (13.87 ± 0.16 ppm, 179.31 ± 1.87 ppm and 3.11 ± 0.06 ppm, respectively). In the immobilization stress-2 group, magnesium (171.56 ± 1.87 ppm, p < 0.05), phosphate (2.44 ± 0.07 ppm, p < 0.001) levels were lower, and manganese (373.68 ± 5.76 ppb, p < 0.001) and copper (2.79 ± 0.15 ppm, p < 0.05) levels were higher than the control group (179.31 ± 1.87 ppm, 3.11 ± 0.06 ppm, 327.25 ± 8.35 ppb and 2.45 ± 0.05 ppm, respectively). Our results indicated that 7-day chronic immobilization stress increased anxiety-related behaviors in both stress groups. Zinc, magnesium, phosphate, copper and manganese levels were affected in the brain.


Author(s):  
Amteshwar Singh Jaggi

Aim: The aim of the present study is to explore the neuroprotective effects of remote ischemic preconditioning in long term cognitive impairment after global cerebral ischemia induced-vascular dementia in mice. Material and methods: The mice were subjected to global cerebral ischemia by occluding the bilateral common carotid arteries for 12 minutes followed by the 24 hours of the reperfusion. The remote ischemic preconditioning stimulus was delivered in the form of 4 cycles of ischemia/reperfusion for 5 minutes each. The cerebral ischemic injury induced-long term cognitive impairment-related learning and memory alterations was assessed using morris water maze, the motor performances of the animals were evaluated using rota-rod test and neurological severity score. The cerebral infract size of the brain were quantified using triphenyltetrazolium chloride staining. Results: Global cerebral ischemia causes long term memory impairment, decreases motor performances and increases the brain infract size in animals. The delivery of remote ischemic preconditioning stimulus significantly abolished the long-term cognitive impairment and ameliorates the motor performances as well as cerebral infract size in brain. Conclusion: The remote ischemic preconditioning mediates neuro protection against global cerebral ischemic injury induced long-term cognitive impairment.


2020 ◽  
Vol 23 (5) ◽  
pp. 402-410 ◽  
Author(s):  
Lin-Zi Li ◽  
Shan-Shan Lei ◽  
Bo Li ◽  
Fu-Chen Zhou ◽  
Ye-Hui Chen ◽  
...  

Aim and Objective: The Dendrobium officinalis flower (DOF) is popular in China due to common belief in its anti-aging properties and positive effects on “nourish yin”. However, there have been relatively few confirmatory pharmacological experiments conducted to date. The aim of this work was to evaluate whether DOF has beneficial effects on learning and memory in senescent rats, and, if so, to determine its potential mechanism of effect. Materials and Methods: SD rats were administrated orally DOF at a dose of 1.38, or 0.46 g/kg once a day for 8 weeks. Two other groups included a healthy untreated control group and a senescent control group. During the 7th week, a Morris water maze test was performed to assess learning and memory. At the end of the experiment, serum and brain samples were collected to measure concentrations of antioxidant enzymes, including malondialdehyde (MDA), superoxide dismutase (SOD), catalase (CAT), and glutathione reductase (GSH-Px) in serum, and the neurotransmitters, including γ-aminobutyric acid (γ-GABA), Glutamic (Glu), and monoamine oxidase B (MAO-B) in the brain. Histopathology of the hippocampus was assessed using hematoxylin-eosin (H&E) staining. Results: The results suggested that treatment with DOF improved learning as measured by escape latency, total distance, and target quadrant time, and also increased levels of γ-GABA in the brain. In addition, DOF decreased the levels of MDA, Glu, and MAO-B, and improved SOD and GSHPx. Histopathological analysis showed that DOF also significantly reduced structural lesions and neurodegeneration in the hippocampus relative to untreated senescent rats. Conclusion: DOF alleviated brain aging and improved the spatial learning abilities in senescent rats, potentially by attenuating oxidative stress and thus reducing hippocampal damage and balancing the release of neurotransmitters.


2019 ◽  
Vol 20 (4) ◽  
pp. 302-308 ◽  
Author(s):  
Carla R.F. Volobuff ◽  
Pedro C.O. Junior ◽  
Sidney M. dos Santos ◽  
Zefa V. Pereira ◽  
Diego C. Ferreira ◽  
...  

Background: The genus Psychotria and Palicourea are reported as a source of alkaloids and iridoids, which exhibit biological activities. This study aimed to evaluate antiproliferative and anticholinesterase activities and quantification of the alkaloids of seven species among the genus found in Mato Grosso do Sul region in Brazil. Methods: Concentrations of alkaloids were measured spectrophotometrically. The extracts were submitted to antiproliferative activity against ten cell lines. The anticholinesterase activity of the extracts was developed using brain structures of male Wistar rats: cerebral cortex, hippocampus, hypothalamus and striatum by the Ellman method. Results: Alkaloids from Psychotria and Palicourea species were quantified which showed values of 47.6 to 21.9 µg/g. Regarding the antiproliferative potential, Palicourea crocea demonstrated selectivity against the 786-0 cell line (GI50: 22.87 µg/mL). Psychotria leiocarpa inhibited cell growth against OVCAR-3 (GI50: 3.28 µg/mL), K-562 (GI50: 5.26 µg/mL), HaCaT (GI50: 27.20 µg/mL), PC-3 (GI50: 34.92 µg/mL), MCF-7 (GI50: 35.80 µg/mL) and P. capillacea showed activity against OVCAR-3 (GI50: 2.33 µg/ml) and U251 (GI50: 16.66 µg/ml). The effect of acetylcholinesterase inhibition was more effective in the hippocampus, demonstrating inhibition for Paliourea crocea, Psychotria deflexa, P. brachybotrya and P. leiocarpa of 70%, 57%, 50% and 40%, respectively, followed by P. poeppigiana and P. capillacea, inhibiting 21%, compared to the control. Conclusion: Herein, the present work showed for the first time, anticholinesterasic and antiproliferative activities of extracts of Palicourea and Psychotria seem to be mainly associated with the levels of alkaloids in the leaves of these species.


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