The effect of reserpine upon experimental coxsackievirus B-3 infection in mice

1972 ◽  
Vol 18 (5) ◽  
pp. 577-582
Author(s):  
E. I. Grodums

Coxsackievirus (cox.) B-3 pathogenicity was markedly augmented in weanling and adult mice during a reserpine treatment. In both age groups the mortality rose to 100% after the 1st week of inoculation.In the olfactory bulb of the reserpine-treated weanling mice the score of viral lesions was 80% compared to 2% in the non-treated. In the heart of the reserpine-treated infected mice it was 62%, while it was 40% without reserpine. In the adult mice the viral tissue damage was aggravated in the interscapular brown adipose pad and the olfactory bulb. Moreover, the viral lesions in the reserpine-treated mice in both age groups showed some striking morphological differences when compared with mice injected with the virus only.The recovered virus yielded higher titers in the reserpine-treated mice in both age groups. In the adult reserpine-treated mice the LD50 of the cox. B-3 recovered from the brain and heart were as high as in the weanlings.

1970 ◽  
Vol 16 (9) ◽  
pp. 833-839 ◽  
Author(s):  
E. I. Grodums ◽  
G. Dempster

On acute cold exposure the normal brown adipose cells in the mouse interscapular pad underwent morphological changes apparently as a result of loss and redistribution of the intracellular lipid globules; on continued cold exposure the globules increased in numbers and size. If adult female mice were inoculated with coxsackievirus B-3 during acute cold exposure and returned to normal room temperature soon afterwards, the viral damage in the brown adipose tissues was seriously aggravated; if on the other hand they were left in the cold for the duration of the infection, the damage was aggravated to a lesser degree. Finally, if cold-acclimated mice were inoculated the lesion was localized in one area of the pad.In contrast, the myocardial damage was aggravated only in those mice which were inoculated during acute cold exposure and left in the cold. The cox. B-3 pathogenesis in the brain showed no clear-cut variations resulting from changes in the ambient temperature. The infectious amount of virus recovered from the heart and brain appeared to be greater and persist longer, if the mice were subjected to a prolonged cold exposure.The cold exposure, however, failed completely to increase the age susceptibility of mice to cox. B-2.


2021 ◽  
Vol 18 (1) ◽  
Author(s):  
Rahul Basu ◽  
Vinod Nair ◽  
Clayton W. Winkler ◽  
Tyson A. Woods ◽  
Iain D. C. Fraser ◽  
...  

Abstract Background A key factor in the development of viral encephalitis is a virus crossing the blood-brain barrier (BBB). We have previously shown that age-related susceptibility of mice to the La Crosse virus (LACV), the leading cause of pediatric arbovirus encephalitis in the USA, was associated with the ability of the virus to cross the BBB. LACV infection in weanling mice (aged around 3 weeks) results in vascular leakage in the olfactory bulb/tract (OB/OT) region of the brain, which is not observed in adult mice aged > 6–8 weeks. Thus, we studied age-specific differences in the response of brain capillary endothelial cells (BCECs) to LACV infection. Methods To examine mechanisms of LACV-induced BBB breakdown and infection of the CNS, we analyzed BCECs directly isolated from weanling and adult mice as well as established a model where these cells were infected in vitro and cultured for a short period to determine susceptibility to virus infection and cell death. Additionally, we utilized correlative light electron microscopy (CLEM) to examine whether changes in cell morphology and function were also observed in BCECs in vivo. Results BCECs from weanling, but not adult mice, had detectable infection after several days in culture when taken ex vivo from infected mice suggesting that these cells could be infected in vitro. Further analysis of BCECs from uninfected mice, infected in vitro, showed that weanling BCECs were more susceptible to virus infection than adult BCECs, with higher levels of infected cells, released virus as well as cytopathic effects (CPE) and cell death. Although direct LACV infection is not detected in the weanling BCECs, CLEM analysis of brain tissue from weanling mice indicated that LACV infection induced significant cerebrovascular damage which allowed virus-sized particles to enter the brain parenchyma. Conclusions These findings indicate that BCECs isolated from adult and weanling mice have differential viral load, infectivity, and susceptibility to LACV. These age-related differences in susceptibility may strongly influence LACV-induced BBB leakage and neurovascular damage allowing virus invasion of the CNS and the development of neurological disease.


2021 ◽  
Vol 383 (1) ◽  
pp. 485-493 ◽  
Author(s):  
Florence Kermen ◽  
Nathalie Mandairon ◽  
Laura Chalençon

AbstractWhether an odorant is perceived as pleasant or unpleasant (hedonic value) governs a range of crucial behaviors: foraging, escaping danger, and social interaction. Despite its importance in olfactory perception, little is known regarding how odor hedonics is represented and encoded in the brain. Here, we review recent findings describing how odorant hedonic value is represented in the first olfaction processing center, the olfactory bulb. We discuss how olfactory bulb circuits might contribute to the coding of innate and learned odorant hedonics in addition to the odorant’s physicochemical properties.


Hypertension ◽  
2015 ◽  
Vol 66 (suppl_1) ◽  
Author(s):  
Kristin E Claflin ◽  
Justin L Grobe

The brain renin-angiotensin system (RAS) and leptin contribute to the control of resting metabolic rate (RMR) and their receptors are co-expressed in areas of the brain critical for metabolic control; thus angiotensin and leptin may interact within the brain to regulate RMR and obesity. Inhibition of the brain RAS attenuates sympathetic nerve activity (SNA) responses to leptin, leading us to hypothesize that the brain RAS mediates the RMR effects of leptin. Mice lacking angiotensin AT 1A receptors in leptin receptor-expressing cells (ObRb-Cre x AT 1A flox/flox ; “KO”) exhibited normal body weight (15 weeks of age: control n=28, 26.0 ± 0.7, vs KO n=35, 25.8 ± 0.6 g), food intake (control n=12, 3.1 ± 0.15, vs KO n=15, 3.4 ± 0.14 g) and RMR (control n=13, 0.15 ± 0.004, vs KO n=15, 0.16 ± 0.006 kcal/hr) on standard chow diet. Brown adipose SNA responses to acute leptin injection, however, were completely attenuated in KO mice. When maintained on a 45% high fat diet (HFD), KO mice gained significantly more fat mass (control n=35, 5.6 ± 0.4, vs KO n=31, 7.4 ± 0.5 g, P<0.05) and body mass (control, 27.4 ± 0.6, vs KO, 29.6 ± 0.6 g, P<0.05) due to a loss of diet-induced thermogenesis (control n=22, 0.18 ± 0.008, vs. KO n=12, 0.16 ± 0.004 kcal/hr, P<0.05). KO mice exhibited attenuated hypothalamic proopiomelanocortin (POMC) gene expression and partially attenuated RMR responses to alpha-melanocyte stimulating hormone (αMSH; control n=3, 0.25 ± 0.01, vs KO n=7, 0.2 ± 0.01 kcal/hr, P<0.05) indicating that the interaction between leptin and AT 1A modulates both αMSH production and action. To localize the site of the brain RAS-leptin interaction, we developed novel multi-transgenic mouse models which expresses GFP via the AT 1A promoter (NZ44, from GenSat) and/or conditional activation of a tdTomato reporter (ROSA-stop flox -tdTomato) in cells expressing the leptin receptor (ObRb-Cre) or agouti-related peptide (AgRP-Cre). Immunohistochemical staining of adrenocorticotropin in brain tissue from NZ44 mice revealed no localization of AT 1A to POMC neurons; in contrast, AT 1A was strongly localized with AgRP promoter activity. Taken together, these data support a critical role for angiotensin AT 1A receptors on AgRP neurons in the arcuate nucleus in resting metabolic rate control.


2017 ◽  
Vol 91 (22) ◽  
Author(s):  
D. Lori Wheeler ◽  
Jeremiah Athmer ◽  
David K. Meyerholz ◽  
Stanley Perlman

ABSTRACT Viral infection of the central nervous system (CNS) is complicated by the mostly irreplaceable nature of neurons, as the loss of neurons has the potential to result in permanent damage to brain function. However, whether neurons or other cells in the CNS sometimes survive infection and the effects of infection on neuronal function is largely unknown. To address this question, we used the rJHM strain (rJ) of mouse hepatitis virus (MHV), a neurotropic coronavirus that causes acute encephalitis in susceptible strains of mice. To determine whether neurons or other CNS cells survive acute infection with this virulent virus, we developed a recombinant JHMV that expresses Cre recombinase (rJ-Cre) and infected mice that universally expressed a silent (floxed) version of tdTomato. Infection of these mice with rJ-Cre resulted in expression of tdTomato in host cells. The results showed that some cells were able to survive the infection, as demonstrated by continued tdTomato expression after virus antigen could no longer be detected. Most notably, interneurons in the olfactory bulb, which are known to be inhibitory, represented a large fraction of the surviving cells. In conclusion, our results indicated that some neurons are resistant to virus-mediated cell death and provide a framework for studying the effects of prior coronavirus infection on neuron function. IMPORTANCE We developed a novel recombinant virus that allows the study of cells that survive an infection by a central nervous system-specific strain of murine coronavirus. Using this virus, we identified neurons and, to a lesser extent, nonneuronal cells in the brain that were infected during the acute phase of the infection and survived for approximately 2 weeks until the mice succumbed to the infection. We focused on neurons and glial cells within the olfactory bulb because the virus enters the brain at this site. Our results show that interneurons of the olfactory bulb were the primary cell type able to survive infection. Further, these results indicate that this system will be useful for functional and gene expression studies of cells in the brain that survive acute infection.


2005 ◽  
Vol 21 (3) ◽  
pp. 351-361 ◽  
Author(s):  
Ralph L. House ◽  
Joseph P. Cassady ◽  
Eugene J. Eisen ◽  
Thomas E. Eling ◽  
Jennifer B. Collins ◽  
...  

Gene expression was measured during t10c12-CLA-induced body fat reduction in a polygenic obese line of mice. Adult mice ( n = 185) were allotted to a 2 × 2 factorial experiment consisting of either nonobese (ICR-control) or obese (M16-selected) mice fed a 7% fat, purified diet containing either 1% linoleic acid (LA) or 1% t10c12-CLA. Body weight (BW) by day 14 was 12% lower in CLA- compared with LA-fed mice ( P < 0.0001). By day 14, t10c12-CLA reduced weights of epididymal, mesenteric, and brown adipose tissues, as a percentage of BW, in both lines by 30, 27, and 58%, respectively, and increased liver weight/BW by 34% ( P < 0.0001). Total RNA was isolated and pooled (4 pools per tissue per day) from epididymal adipose ( days 5 and 14) of the obese mice to analyze gene expression profiles using Agilent mouse oligo microarray slides representing >20,000 genes. Numbers of genes differentially expressed by greater than or equal to twofold in epididymal adipose ( days 5 and 14) were 29 and 125, respectively. It was concluded that, in adipose tissue, CLA increased expression of uncoupling proteins (1 and 2), carnitine palmitoyltransferase system, tumor necrosis factor-α ( P < 0.05), and caspase-3 but decreased expression of peroxisome proliferator-activated receptor-γ, glucose transporter-4, perilipin, caveolin-1, adiponectin, resistin, and Bcl-2 ( P < 0.01). In conclusion, this experiment has revealed candidate genes that will be useful in elucidating mechanisms of adipose delipidation.


2008 ◽  
Vol 32 (6s1) ◽  
pp. 368A-368A
Author(s):  
Julie A. Owen ◽  
Oscar Velasquez ◽  
Patricia S. Levin ◽  
Yan Wang ◽  
Harish Krishnan ◽  
...  

1996 ◽  
Vol 271 (1) ◽  
pp. E151-E158 ◽  
Author(s):  
H. L. Chen ◽  
D. R. Romsos

A single intracerebroventricular injection of dexamethasone (DEX) rapidly (within 30 min) suppresses brown adipose tissue thermogenesis and increases plasma insulin concentrations in adrenal-ectomized (ADX) ob/ob mice but not in ADX lean mice. Intracerebroventricular neuropeptide Y (NPY) administered intracerebroventricularly causes these same metabolic changes within 30 min in both ob/ob and lean ADX mice. We therefore hypothesized that DEX exerts these rapid-onset metabolic actions in ob/ob mice via a phenotype-specific enhancement of NPY secretion within the central nervous system. In support of this hypothesis, DEX (a type II glucocorticoid receptor agonist) administered intracerebroventricularly selectively lowered NPY concentrations in the whole hypothalamus of ADX ob/ob mice by 35% and in the arcuate nucleus region by approximately 70% within 30 min but not in the brain stem or hippocampus or in any of these regions of lean mice. DEX also functioned in vitro to enhance depolarization-dependent release of NPY from hypothalamic blocks of ADX ob/ob mice but not of ADX lean mice. Thus DEX acts in the hypothalamus of ob/ob mice in a phenotype-specific manner to evoke rapid transport of NPY from cell bodies within the arcuate nucleus to terminal regions including the dorsomedial and ventromedial hypothalamic regions for release.


2021 ◽  
Author(s):  
◽  
Yamna Rahim

Obesity is adetrimental health condition that occurs when energy intake, exceeds energy expenditure. Pituitary adenylatecyclase-activating polypeptide (PACAP) regulates energy expenditure, including adaptive thermogenesis, through the hypothalamic-sympatheticnervous system-brown adipose tissue axis. We hypothesize that PACAP expression in the ventromedial nucleus (VMN) is required for adaptive thermogenesis. To assess this, our goal is to develop an animal model that expresses PACAP specifically in the VMN of the hypothalamus. As a first step to achieving this goal, we established a protocol to deliver an adeno-associatedvirus (AAV) expressing the visible protein eGFP under the control of a VMN-specific promoter, steroidogenic factor 1 (SF1) using stereotaxic surgery. A second step was to develop a protocol to detect PACAP mRNA in the brain using in situ hybridization. Our results showed that the stereotaxic protocol was successful and provides significant progress towards achieving PACAP-specific expression in the VMN.


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