Search results for "MESH: Animals"
showing 10 items of 121 documents
Environmental stress affects the expression of a carotenoid-based sexual trait in male zebra finches.
2007
SUMMARY Abiotic factors including thermal stress are suggested to exert constrains on sexual ornaments through trade-offs between sexual displays and physiological functions related to self-maintenance. Given the health properties of carotenoid pigments, carotenoid-based ornaments offer a relevant context in which to investigate the effect of environmental stress, such as ambient temperature, on the production and maintenance of secondary sexual traits and, also, to explore the proximate mechanisms shaping their expression. In this study, we exposed male zebra finches (Taeniopygia guttata) to environmental stress by exposing them to two temperature regimes (6 and 26°C) over a 4 week period.…
Independence of first- and second-order memories in newborn rabbits
2011
WOS:000291649400006; International audience; The mammary pheromone promotes the acquisition of novel odorants (CS1) in newborn rabbits. Here, experiments pinpoint that CS1 becomes able to support neonatal learning of other odorants (CS2). We therefore evaluated whether these first- and second-order memories remained dependent after reactivation. Amnesia induced after CS2 recall selectively blocked this memory, when recall and amnesia of CS1 left the souvenir of CS2 safe; this finding partially differed from results obtained in adult mammals. Thus, in this model of neonatal appetitive odor learning, second-order memory seems to depend on first-order memory for its formation but not for its m…
Acute in vivo administration of a fish oil-containing emulsion improves post-ischemic cardiac function in n-3-depleted rats
2006
International audience; A novel i.v. lipid preparation (MCT:FO) containing 80% medium chain-triacylglycerols and 20% fish oil was recently developed to rapidly replenish cell membrane phospholipids with omega 3 (n-3) polyunsaturated fatty acids (PUFA). In regard of this property, we investigated the effect of a single i.v. administration of MCT:FO on the recovery of cardiac function after ischemia in control and n-3-depleted rats. Results were compared with those obtained either with a control preparation, where FO was replaced by triolein (MCT:OO), or with saline. Saline (1 ml) or lipid preparation (also 1 ml) was injected as a bolus via the left saphenous vein. After 60 min the heart was …
Effects of typical inducers on olfactory xenobiotic-metabolizing enzyme, transporter, and transcription factor expression in rats.
2010
International audience; Several xenobiotic-metabolizing enzymes (XMEs) have been identified in the olfactory mucosa (OM) of mammals. However, the molecular mechanisms underlying the regulation of these enzymes have been little explored. In particular, information on the expression of the transcriptional factors in this tissue is quite limited. The aim of the present study was to examine the impact of five typical inducers, Aroclor 1254, 3-methylcholanthrene, dexamethasone, phenobarbital, and ethoxyquin, on the activities and mRNA expression of several XMEs in the OM and in the liver of rats. We also evaluated the effects of these treatments on the mRNA expression of transcription factors an…
Grape seed and skin extract reduces pancreas lipotoxicity, oxidative stress and inflammation in high fat diet fed rats.
2016
IF 2.326; International audience; Obesity is related to an elevated risk of diabetes and the mechanisms whereby fat adversely affects the pancreas are poorly understood. We studied the effect of a high fat diet (HFD) on pancreas steatosis, oxidative stress and inflammation as well as the putative protection afforded by grape seed and skin extract (GSSE). HFD induced body weight gain, without affecting insulinemia, nor glycemia and dropped adiponectemia. HFD also provoked the ectopic deposition of cholesterol and triglyceride, and an oxidative stress characterized by increased lipoperoxidation and carbonylation, inhibition of antioxidant enzyme activities such as CAT, GPx and SOD, depletion …
General oxidative stress during doxorubicin-induced cardiotoxicity in rats: Absence of cardioprotection and low antioxidant efficiency of alpha-lipoi…
2012
International audience; To evaluate the effects of alpha-lipoic acid (AL) in a model of doxorubicin (DOX)-induced cardiotoxicity, male Wistar rats were treated with DOX (1 mg/kg/d; 10 d) in combination or not with AL (50 mg/kg/d; 15 d). Plasma oxidative stress was determined by hydroperoxides (ROOH) and the ascorbyl radical/ascorbate ratio. One and two months later, the functional parameters of the hearts were determined in vivo by catheterization and cardiac oxidative stress was assessed by malonedialdehyde (MDA) and O₂*⁻ (dihydroethidium fluorescence) content in tissue. After two months, body weight was higher in the DOX-AL group than in DOX (+16%), but this was due to ascites. Histologic…
Dietary polyunsaturated fatty acids reduce retinal stress induced by an elevation of intraocular pressure in rats.
2011
International audience; N-6 and n-3 polyunsaturated fatty acids (PUFAs) have been shown to prevent tissue release of inflammatory molecules. We have shown that a combination of n-6 and n-3 PUFAs is more efficient than single supplementations on the long-term consequences of intraocular pressure elevation. We hypothesized that such an association is also more effective during early retinal stress by modifying retinal proinflammatory prostaglandin and cytokine productions. Rats were supplemented for 3 months with n-6 PUFAs, n-3 PUFAs, or both n-6 and n-3 PUFAs. After 3 months, a surgical elevation of intraocular pressure was induced. Retinal morphometry and glial cell activation were evaluate…
Understanding Cannabinoid Psychoactivity with Mouse Genetic Models
2007
Marijuana and its main psychotropic ingredient Δ9-tetrahydrocannabinol (THC) exert a plethora of psychoactive effects through the activation of the neuronal cannabinoid receptor type 1 (CB1), which is expressed by different neuronal subpopulations in the central nervous system. The exact neuroanatomical substrates underlying each effect of THC are, however, not known. We tested locomotor, hypothermic, analgesic, and cataleptic effects of THC in conditional knockout mouse lines, which lack the expression of CB1 in different neuronal subpopulations, including principal brain neurons, GABAergic neurons (those that release γ aminobutyric acid), cortical glutamatergic neurons, and neurons expres…
Olfactory bulbectomy, but not odor conditioned aversion, induces the differentiation of immature neurons in the adult rat piriform cortex.
2011
International audience; The piriform cortex layer II of young-adult rats presents a population of prenatally generated cells, which express immature neuronal markers, such as the polysialylated form of the neural cell adhesion molecule (PSA-NCAM) or doublecortin (DCX), and display structural characteristics of immature neurons. The number of PSA-NCAM/DCX expressing cells in this region decreases markedly as age progresses, suggesting that these cells differentiate or die. Since the piriform cortex receives a major input from the olfactory bulb and participates in olfactory information processing, it is possible that the immature neurons in layer II are affected by manipulations of the olfac…
Tenectin is a novel alphaPS2betaPS integrin ligand required for wing morphogenesis and male genital looping in Drosophila.
2010
International audience; Morphogenesis of the adult structures of holometabolous insects is regulated by ecdysteroids and juvenile hormones and involves cell-cell interactions mediated in part by the cell surface integrin receptors and their extracellular matrix (ECM) ligands. These adhesion molecules and their regulation by hormones are not well characterized. We describe the gene structure of a newly described ECM molecule, tenectin, and demonstrate that it is a hormonally regulated ECM protein required for proper morphogenesis of the adult wing and male genitalia. Tenectin's function as a new ligand of the PS2 integrins is demonstrated by both genetic interactions in the fly and by cell s…