scholarly journals Mutated Measles Virus Matrix and Fusion Protein Influence Viral Titer In Vitro and Neuro-Invasion in Lewis Rat Brain Slice Cultures

Viruses ◽  
2021 ◽  
Vol 13 (4) ◽  
pp. 605
Author(s):  
Johannes Busch ◽  
Soroth Chey ◽  
Michael Sieg ◽  
Thomas W. Vahlenkamp ◽  
Uwe G. Liebert

Measles virus (MV) can cause severe acute diseases as well as long-lasting clinical deteriorations due to viral-induced immunosuppression and neuronal manifestation. How the virus enters the brain and manages to persist in neuronal tissue is not fully understood. Various mutations in the viral genes were found in MV strains isolated from patient brains. In this study, reverse genetics was used to introduce mutations in the fusion, matrix and polymerase genes of MV. The generated virus clones were characterized in cell culture and used to infect rat brain slice cultures. A mutation in the carboxy-terminal domain of the matrix protein (R293Q) promoted the production of progeny virions. This effect was observed in Vero cells irrespective of the expression of the signaling lymphocyte activation molecule (SLAM). Furthermore, a mutation in the fusion protein (I225M) induced syncytia formation on Vero cells in the absence of SLAM and promoted viral spread throughout the rat brain slices. In this study, a solid ex vivo model was established to elucidate the MV mutations contributing to neural manifestation.

1995 ◽  
Vol 7 (3) ◽  
pp. 385 ◽  
Author(s):  
LD Longo ◽  
S Packianathan

Recent studies in vivo have demonstrated that ornithine decarboxylase (ODC) activity in the fetal rat brain is elevated 4-5-fold by acute maternal hypoxia. This hypoxic-associated increase is seen in the rat brain in both the newborn and the adult. Because of the intimate involvement of ODC in transcription and translation, as well as in growth and development, it is imperative that the manner in which hypoxia affects the regulation of this enzyme be better understood. In order to achieve this, a brain preparation in vitro was required to eliminate the confounding effects of the dam on the fetal and newborn brain ODC activity in vivo. Therefore, brain slices from 3-4-day-old (P-3) newborn rats were utilized to test the hypothesis that ODC activity increases in response to hypoxia in vitro. Cerebral slices from the P-3 rat pups were allowed to equilibrate and recover in artificial cerebrospinal fluid (ACSF) continuously bubbled with a mixture of 95% O2 and 5% CO2 for 1 h before beginning hypoxic exposures. Higher basal ODC activities were obtained by treating the slices with 0.03% fetal bovine serum (FBS) and 0.003% bovine serum albumin (BSA), rather than with ACSF alone. Hypoxia was induced in the slices by replacing the gas with 40%, 21%, 10%, or 5% O2, all with 5% CO2 and balance N2. With FBS and BSA treatment, ODC activity was maintained at about 0.15-0.11 nM CO2 mg-1 protein h-1 throughout the experiment, which was 2-3-fold higher than that without FBS and BSA. ODC activity increased significantly and peaked between 1 h and 2 h after initiation of hypoxia. For instance, with 21% O2, ODC activity increased approximately 1.5-fold at 1 h and approximately 2-fold at 2 h. These studies demonstrate that: (1) the hypoxic-induced increases observed in vivo in the fetal and newborn rat brain ODC activity can be approximated in a newborn rat brain slice preparation in vitro; (2) newborn rat brain slice preparations may provide an alternative to methods in vivo or cell culture methods for studying the regulation of acute hypoxic-induced enzymes; and (3) high, stable baseline ODC activities in brain slices suggest that the cells in the slice are capable of active metabolism if FBS and BSA are available to mimic conditions in vivo.


2020 ◽  
Vol 76 (12) ◽  
pp. 10090-10121
Author(s):  
Yung-Kuan Chan ◽  
Chun-Fu Hong ◽  
Meng-Hsiun Tsai ◽  
Ya-Lan Chang ◽  
Ping-Hsuan Sun

Abstract Stroke is one of the leading causes of death as well as results in a massive economic burden for society. Stroke is a cerebrovascular disease mainly divided into two types: ischemic stroke and hemorrhagic stroke, which, respectively, refer to the partial blockage and bleeding inside brain blood vessels. Both stroke types lead to nutrient and oxygen deprivation in the brain, which ultimately cause brain damage or death. This study focuses on ischemic stroke in rats with middle cerebral artery occlusion (MCAO) as experimental subjects, and the volumes of infarct and atrophy are calculated based on the brain slice images of rat brains stained with 2,3,5-triphenyl tetrazolium chloride. In this study, a stroke rat brain infarct and atrophy volumes computation system (SRBIAVC system) is developed to segment the infarcts and atrophies from the rat brain slice images. Based on the segmentation results, the infarct and atrophy volumes of a rat brain can be computed. In this study, 168 images of brain slices cut from 28 rat brains with MCAO are used as the test samples. The experimental results show that the segmentation results obtained by the SRBIAVC system are close to those obtained by experts.


2000 ◽  
Vol 84 (2) ◽  
pp. 1093-1097 ◽  
Author(s):  
Virginia Tancredi ◽  
Giuseppe Biagini ◽  
Margherita D'Antuono ◽  
Jacques Louvel ◽  
René Pumain ◽  
...  

We obtained rat brain slices (550–650 μm) that contained part of the frontoparietal cortex along with a portion of the thalamic ventrobasal complex (VB) and of the reticular nucleus (RTN). Maintained reciprocal thalamocortical connectivity was demonstrated by VB stimulation, which elicited orthodromic and antidromic responses in the cortex, along with re-entry of thalamocortical firing originating in VB neurons excited by cortical output activity. In addition, orthodromic responses were recorded in VB and RTN following stimuli delivered in the cortex. Spontaneous and stimulus-induced coherent rhythmic oscillations (duration = 0.4–3.5 s; frequency = 9–16 Hz) occurred in cortex, VB, and RTN during application of medium containing low concentrations of the K+ channel blocker 4-aminopyridine (0.5–1 μM). This activity, which resembled electroencephalograph (EEG) spindles recorded in vivo, disappeared in both cortex and thalamus during application of the excitatory amino acid receptor antagonist kynurenic acid in VB ( n = 6). By contrast, cortical application of kynurenic acid ( n = 4) abolished spindle-like oscillations at this site, but not those recorded in VB, where their frequency was higher than under control conditions. Our findings demonstrate the preservation of reciprocally interconnected cortical and thalamic neuron networks that generate thalamocortical spindle-like oscillations in an in vitro rat brain slice. As shown in intact animals, these oscillations originate in the thalamus where they are presumably caused by interactions between RTN and VB neurons. We propose that this preparation may help to analyze thalamocortical synchronization and to understand the physiopathogenesis of absence attacks.


1993 ◽  
Vol 264 (4) ◽  
pp. R716-R719 ◽  
Author(s):  
R. S. Young ◽  
M. J. During ◽  
D. F. Donnelly ◽  
W. J. Aquila ◽  
V. L. Perry ◽  
...  

Using in vitro microdialysis, we tested the hypothesis that anoxia-induced release of excitatory amino acids is greater in adult rat brain than in turtle brain. Ten minutes of anoxia produced significant elevation of glutamate (from 0.39 +/- 0.03 to 0.90 +/- 0.18 microM dialysate, means +/- SE, P < 0.05), aspartate (from 0.28 +/- 0.12 to 1.20 +/- 0.49 microM, P < 0.05), glycine, and alanine in the rat brain slice. During reoxygenation, alanine and glycine returned toward baseline values, whereas aspartate and glutamate remained elevated. In contrast, prolonged anoxia (60 min) in the turtle brain slice resulted in only minimal increase in aspartate (from 0.06 +/- 0.01 to 0.09 +/- 0.02 microM, P < 0.05) and, interestingly, a decrease in glutamate (from 0.50 +/- 0.11 to 0.33 +/- 0.09 microM, P < 0.05). Levels of glycine, alanine, and taurine were unchanged. We conclude that oxygen deprivation causes marked increase in excitatory amino acids in the anoxia-sensitive rat brain slice, while oxygen deprivation for an even longer period of time in the turtle brain slice produces substantially less change. We speculate that the difference in sensitivity to anoxia between rat and turtle is at least partly attributable to the major difference in interstitial levels of excitotoxic amino acids during oxygen deprivation.


2004 ◽  
Vol 137 (2) ◽  
pp. 257-263 ◽  
Author(s):  
Brian A. Koeneman ◽  
Kee-Keun Lee ◽  
Amarjit Singh ◽  
Jiping He ◽  
Gregory B. Raupp ◽  
...  

1994 ◽  
Vol 52 (1) ◽  
pp. A11
Author(s):  
M.T. Espanol ◽  
L. Litt ◽  
L.-H. Chang ◽  
T.L. James ◽  
P.R. Weinstein ◽  
...  

1992 ◽  
Vol 70 (S1) ◽  
pp. S269-S277 ◽  
Author(s):  
Joseph C. LaManna ◽  
J. Keven Griffith ◽  
Boris R. Cordisco ◽  
Chii-Wann Lin ◽  
W. David Lust

Intracellular pH can be measured quantitatively in rat brain in vivo and in vitro using spectrophotometric detection of the vital dye neutral red. This method preserves spatial information and is compatible with microhistochemistry. The intracellular pH indicated by this method is in close agreement with that indicated by 31P-NMR spectroscopy. During ischemia, intracellular acidification is correlated with tissue lactate accumulation. The spatial distribution of pH values becomes more heterogeneous as the tissue becomes more acidic. Resuscitation from total cerebral ischemia produced by cardiac arrest results in rapid intracellular realkalinization. This realkalinization is at least partially inhibited by amiloride pretreatment. Some neuronal populations, especially in the hippocampal CA1 and CA4 regions, may become more acidic during ischemia and realkalinize more slowly after reperfusion than other tissue regions. The intracellular pH of hippocampal brain slice preparations is more alkaline than expected from in vivo studies. The intracellular pH of the brain slice can be acidified to near neutrality by specific inhibitors of the sodium/hydrogen ion exchanger.Key words: hippocampal brain slice, intracellular pH, neutral red, cardiac arrest and resuscitation, sodium/hydrogen ion exchanger.


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