scholarly journals A Multimodal MR Imaging Study of the Effect of Hippocampal Damage on Affective and Cognitive Functions in a Rat Model of Chronic Exposure to a Plateau Environment

Author(s):  
Dongyong Zhu ◽  
Bo He ◽  
Mengdi Zhang ◽  
Yixuan Wan ◽  
Ruibin Liu ◽  
...  

AbstractProlonged exposure to high altitudes above 2500 m above sea level (a.s.l.) can cause cognitive and behavioral dysfunctions. Herein, we sought to investigate the effects of chronic exposure to plateau hypoxia on the hippocampus in a rat model by using voxel-based morphometry, creatine chemical exchange saturation transfer (CrCEST) and dynamic contrast-enhanced MR imaging techniques. 58 healthy 4-week-old male rats were randomized into plateau hypoxia rats (H group) as the experimental group and plain rats (P group) as the control group. H group rats were transported from Chengdu (500 m a.s.l.), a city in a plateau located in southwestern China, to the Qinghai–Tibet Plateau (4250 m a.s.l.), Yushu, China, and then fed for 8 months there, while P group rats were fed in Chengdu (500 m a.s.l.), China. After 8 months of exposure to plateau hypoxia, open-field and elevated plus maze tests revealed that the anxiety-like behavior of the H group rats was more serious than that of the P group rats, and the Morris water maze test revealed impaired spatial memory function in the H group rats. Multimodal MR imaging analysis revealed a decreased volume of the regional gray matter, lower CrCEST contrast and higher transport coefficient Ktrans in the hippocampus compared with the P group rats. Further correlation analysis found associations of quantitative MRI parameters of the hippocampus with the behavioral performance of H group rats. In this study, we validated the viability of using noninvasive multimodal MR imaging techniques to evaluate the effects of chronic exposure to a plateau hypoxic environment on the hippocampus.

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.


2020 ◽  
Vol 31 (1) ◽  
pp. 49
Author(s):  
Festi Artika Sari ◽  
Willy Sandhika ◽  
Tri Hartini Yuliawati

<p class="ISIABSTRAKINGGRIS">Gastritis is an inflammation of the gastric mucosa. Tulsi leaf extract has phenol, flavonoid and saponin compounds which are potential as antioxidant and increase defensive factors in the gastric. The purpose of this research was to find out the effect of tulsi (Ocimum sanctum) leaf extract in polymorphonuclear (PMN) inflammatory cell infiltration in gastric of aspirin-induced gastritis rat model. This study was laboratory experimental research using post-test only control group design. Randomly, 27 male rats were divided into 3 groups, the first group was not induced by aspirin and extract as negative control, the second group was induced by aspirin of 600 mg/kgBW as positive control, and the third group was induced by aspirin of 600 mg/kgBW and was given Ocimum sanctum extract at a dose of 400 mg/kgBW as treatment group. Gastric of the rats were taken on 16th day for histopathology evaluation using hematoxylin and eosin (HE) staining. Evaluation was done by calculating the PMN inflammatory cell infiltration in mucosal and submucosal layer. The results of the average number of PMN inflammatory cell in the gastric tissue of the treatment group showed a significant decrease compared to the positive and negative control groups with P-value &lt;0.05. This study proved that Ocimum sanctum leaf extract administration with the dose of 400 mg/kgBW can decrease gastritis inflammation by reducing PMN inflammatory cell in gastric of aspirin-induced gastritis rat model.</p>


2021 ◽  
Vol 2021 ◽  
pp. 1-6
Author(s):  
Banu Taskin ◽  
Mümin Alper Erdoğan ◽  
Gürkan Yiğittürk ◽  
Sibel Alper ◽  
Oytun Erbaş

Purpose. The aim of the study is to examine the possible therapeutic effects of a known cardiac glycoside, digoxin, on a rat model of MTX-induced hepatotoxicity. Methods. The study was conducted on twenty-four male rats. While eighteen rats received a single dose of 20 mg/kg MTX to obtain an injured liver model, six rats constituted the control group. Also, the eighteen liver toxicity model created rats were equally divided into two groups, one of which received digoxin 0.1 mg/kg/day digoxin (Group 1) and the other group (Group 2) was given saline (% 0.9NaCl) with a dose of 1 ml/kg/day for ten days. Following the trial, the rats were sacrificed to harvest blood and liver tissue samples to determine blood and tissue MDA, serum ALT, plasma TNF-α, TGF-β, IL-6, IL-1-Beta, and PTX3 levels. Results. MTX’s structural and functional hepatotoxicity was observable and evidenced by relatively worse histopathological scores and increased biochemical marker levels. Digoxin treatment significantly reduced the liver enzyme ALT, plasma TNF-α, TGF-β, PTX3, and MDA levels and decreased histological changes in the liver tissue with MTX-induced hepatotoxicity in the rat model. Conclusion. We suggest that digoxin has an anti-inflammatory and antihepatotoxic effect on the MTX-induced liver injury model.


2019 ◽  
Vol 20 (1) ◽  
Author(s):  
Prangtip Potewiratnanond ◽  
Supang Maneesri le Grand ◽  
Anan Srikiatkhachorn ◽  
Weera Supronsinchai

Abstract Background The pathogenesis of medication overuse headache (MOH) involves hyperexcitability of cortical and trigeminal neurons. Derangement of the brainstem modulating system, especially raphe nuclei may contribute to this hyperexcitability. The present study aimed to investigate the involvement of the nucleus raphe magnus (NRM) in the development of cortical and trigeminal hyperexcitability in a rat model of MOH. Results Chronic treatment with acetaminophen increased the frequency of cortical spreading depression (CSD) and the number of c-Fos-immunoreactive (Fos-IR) neurons in the trigeminal nucleus caudalis (TNC). In the control group, muscimol microinjected into the NRM increased significantly the frequency of CSD-evoked direct current shift and Fos-IR neurons in the TNC. This facilitating effect was not found in rats with chronic acetaminophen exposure. In a model of migraine induced by intravenous systemic infusion of nitroglycerin (NTG), rats with chronic exposure to acetaminophen exhibited significantly more frequent neuronal firing in the TNC and greater Fos-IR than those without the acetaminophen treatment. Muscimol microinjection increased neuronal firing in the TNC in control rats, but not in acetaminophen-treated rats. The number of Fos-IR cells in TNC was not changed significantly. Conclusion Chronic exposure to acetaminophen alters the function of the NRM contributing to cortical hyperexcitability and facilitating trigeminal nociception.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Cherry Kim ◽  
Sang Hoon Jeong ◽  
Jaeyoung Kim ◽  
Ja Young Kang ◽  
Yoon Jeong Nam ◽  
...  

AbstractWe aimed to investigate the effect of chronic particulate matter (PM) exposure on bleomycin-induced lung fibrosis in a rat model using chest CT, histopathologic evaluation, and RNA-sequencing. A bleomycin solution was intratracheally administrated to 20 male rats. For chronic PM exposure, after four weeks of bleomycin treatment to induce lung fibrosis, PM suspension (experimental group) or normal saline (control group) was intratracheally administrated for 10 weeks. Chest CT was carried out in all rats, and then both lungs were extracted for histopathologic evaluation. One lobe from three rats in each group underwent RNA sequencing, and one lobe from five rats in each group was evaluated by western blotting. Inflammation and fibrosis scores in both chest CT and pathologic analysis were significantly more aggravated in rats with chronic PM exposure than in the control group. Several genes associated with inflammation and immunity were also upregulated with chronic PM exposure. Our study revealed that chronic PM exposure in a bleomycin-induced lung fibrosis rat model aggravated pulmonary fibrosis and inflammation, proven by chest CT, pathologic analysis, and RNA sequencing.


2018 ◽  
Vol 32 ◽  
pp. 205873841878551 ◽  
Author(s):  
Mohamed A Hamzawy ◽  
Yasmin B El-Ghandour ◽  
Sekena H Abdel-Aziem ◽  
Zoba H Ali

The aspect of treatment of autistic behaviour was investigated using valproic acid rat model of pregnant female rats. Two main groups (10 male rats/group) were treated for 6 days and then divided into six subgroups. The first group of normal rats was divided into three subgroups: (A) – control group, (B) – treated with camel milk (CAM; 2 mL/p.o) and (C) – treated with leptin (1000 µg/kg i.p) twice daily. The second group of autistic rats was randomly distributed into four subgroups as follows: (D) – positive control (autistics rats), (E) – treated with CAM, (F) – treated with a moderate dose of leptin and (G) – treated with a higher dose of leptin. Autistic behaviours of male offspring were checked by grooming and elevated pulz maze tests. Valproic acid (VPA)-induced autistic rats showed severe changes in oxidative stress markers, neurotransmitters and inflammatory cytokines, besides genotoxic manifestation of expression of tumour necrosis factor (TNF)-α, Bax and caspase-3. Leptin or CAM alone showed no signs of toxicity. CAM showed pronounced improvement in control rats than control itself. Leptin or CAM treatment of autistic animals showed a significant improvement of all measured parameters and genetic expression values. The improvement was pronounced in animals treated with CAM. These results suggest that CAM is a potential therapeutic candidate for autism via regulation of inflammatory and apoptotic pathways. Leptin plays an essential role in alleviation of autistic behaviour through antioxidant effects.


Biology ◽  
2019 ◽  
Vol 9 (1) ◽  
pp. 6 ◽  
Author(s):  
Lamiaa M. Shawky ◽  
Ahmed A. Morsi ◽  
Eman El Bana ◽  
Safaa Masoud Hanafy

Sitagliptin, a dipeptidyl peptidase-4 (DPP-4) inhibitor, is a beneficial class of antidiabetic drugs. However, a major debate about the risk of developing pancreatitis is still existing. The aim of the work was to study the histological and immunohistochemical effects of sitagliptin on both endocrine and exocrine pancreases in a rat model of type 2 diabetes mellitus and to correlate these effects with the biochemical findings. Moreover, a possible synergistic effect of sitagliptin, in combination with metformin, was also evaluated. Fifty adult male rats were used and assigned into five equal groups. Group 1 served as control. Group 2 comprised of untreated diabetic rats. Group 3 diabetic rats received sitagliptin. Group 4 diabetic rats received metformin. Group 5 diabetic rats received both combined. Treatments were given for 4 weeks after the induction of diabetes. Blood samples were collected for biochemical assay before the sacrification of rats. Pancreases were removed, weighed, and were processed for histological and immunohistochemical examination. In the untreated diabetic group, the islets appeared shrunken with disturbed architecture and abnormal immunohistochemical reactions for insulin, caspase-3, and inducible nitric oxide synthase (iNOS). The biochemical findings were also disturbed. Morphometrically, there was a significant decrease in the islet size and islet number. Treatment with sitagliptin, metformin, and their combination showed an improvement, with the best response in the combined approach. No evidence of pancreatic injury was identified in the sitagliptin-treated groups. In conclusion, sitagliptin had a cytoprotective effect on beta-cell damage. Furthermore, the data didn’t indicate any detrimental effects of sitagliptin on the exocrine pancreas.


2020 ◽  
Vol 18 (1) ◽  
Author(s):  
Anna Levkovsky ◽  
Rima Dardik ◽  
Daniel Barazany ◽  
David M. Steinberg ◽  
Mark Dan Kirichenko ◽  
...  

Abstract Background Air travel thrombosis continues to be a controversial topic. Exposure to hypoxia and hypobaric conditions during air travel is assumed a risk factor. The aim of this study is to explore changes in parameters of coagulation, fibrinolysis and blood flow in a rat model of exposure to hypobaric conditions that imitate commercial and combat flights. Methods Sixty Sprague-Dawley male rats, aged 10 weeks, were divided into 5 groups according to the type and duration of exposure to hypobaric conditions. The exposure conditions were 609 m and 7620 m for 2 and 12 h duration. Blood count, thrombin– antithrombin complex, D-dimer, interleukin-1 and interleukin-6 were analyzed. All rats went through flight angiography MRI at day 13-post exposure. Results No effect of the various exposure conditions was observed on coagulation, fibrinolytic system, IL-1 or IL-6. MRI angiography showed blood flow reduction in lower limb to less than 30% in 50% of the rats. The reduction in blood flow was more pronounced in the left vessel than in the right vessel (p = 0.006, Wilcoxon signed rank test). The extent of occlusion differed across exposure groups in the right, but not the left vessel (p = 0.002, p = 0.150, respectively, Kruskal-Wallis test). However, these differences did not correlate with the exposure conditions. Conclusion In the present rat model, no clear correlation between various hypobaric conditions and activation of coagulation was observed. The reduction in blood flow in the lower limb also occurred in the control group and was not related to the type of exposure.


2020 ◽  
Vol 22 (5) ◽  
pp. 1197-1207 ◽  
Author(s):  
Maria Elisa Serrano ◽  
Mohamed Ali Bahri ◽  
Guillaume Becker ◽  
Alain Seret ◽  
Charlotte Germonpré ◽  
...  

Abstract Purpose The main purpose of this study was to understand how the positron emission tomography (PET) measure of the synaptic vesicle 2A (SV2A) protein varies in vivo during the development of temporal lobe epilepsy (TLE) in the kainic acid rat model. Procedures Twenty Sprague Dawley male rats were administered with multiple systemic doses of saline (control group, n = 5) or kainic acid (5 mg/kg/injection, epileptic group, n = 15). Both groups were scanned at the four phases of TLE (early, latent, transition, and chronic phase) with the [18F]UCB-H PET radiotracer and T2-structural magnetic resonance imaging. At the end of the scans (3 months post-status epilepticus), rats were monitored for 7 days with electroencephalography for the detection of spontaneous electrographic seizures. Finally, the immunofluorescence staining for SV2A expression was performed. Results Control rats presented a significant increase in [18F]UCB-H binding at the last two scans, compared with the first ones (p < 0.001). This increase existed but was lower in epileptic animals, producing significant group differences in all the phases of the disease (p < 0.028). Furthermore, the quantification of the SV2A expression in vivo with the [18F]UCB-H radiotracer or ex vivo with immunofluorescence led to equivalent results, with a positive correlation between both. Conclusions Even if further studies in humans are required, the ability to detect a progressive decrease in SV2A expression during the development of temporal lobe epilepsy supports the use of [18F]UCB-H as a useful tool to differentiate, in vivo, between healthy and epileptic animals along with the development of the epileptic disease.


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