Search results for "Cell adhesion molecule"
showing 10 items of 469 documents
Chronic stress induces changes in the structure of interneurons and in the expression of molecules related to neuronal structural plasticity and inhi…
2011
Chronic stress in experimental animals, one of the most accepted models of chronic anxiety and depression, induces structural remodeling of principal neurons in the amygdala and increases its excitation by reducing inhibitory tone. These changes may be mediated by the polysialylated form of the neural cell adhesion molecule (PSA-NCAM), a molecule related to neuronal structural plasticity and expressed by interneurons in the adult CNS, which is downregulated in the amygdala after chronic stress. We have analyzed the amygdala of adult mice after 21 days of restraint stress, studying with qRT-PCR the expression of genes related to general and inhibitory neurotransmission, and of PSA synthesizi…
The dendritic spines of interneurons are dynamic structures influenced by PSA-NCAM expression.
2013
Excitatory neurons undergo dendritic spine remodeling in response to different stimuli. However, there is scarce information about this type of plasticity in interneurons. The polysialylated form of the neural cell adhesion molecule (PSA-NCAM) is a good candidate to mediate this plasticity as it participates in neuronal remodeling and is expressed by some mature cortical interneurons, which have reduced dendritic arborization, spine density, and synaptic input. To study the connectivity of the dendritic spines of interneurons and the influence of PSA-NCAM on their dynamics, we have analyzed these structures in a subpopulation of fluorescent spiny interneurons in the hippocampus of glutamic …
PSA-NCAM expression in the piriform cortex of the adult rat. Modulation by NMDA receptor antagonist administration.
2002
Administration of NMDA receptor antagonists upregulates the expression of the polysialylated form of the neural cell adhesion molecule (PSA-NCAM) in the adult hippocampus. Since the piriform cortex is also populated by PSA-NCAM immunoreactive neurons during adulthood, we sought to characterize them in detail and to test whether NMDA receptor antagonists also modulate PSA-NCAM in this cortical region. PSA-NCAM immunoreactivity is located mainly in layer II, where many neurogliaform and some pyramidal-semilunar transitional neurons are labeled. Many large neurons in layer III and endopiriform nucleus also express PSA-NCAM. Interestingly, some small labeled cells resembling migratory neuroblas…
Inhibition of cancer growth by resveratrol is related to its low bioavailability.
2002
The relationship between resveratrol (RES) bioavalability and its effect on tumor growth was investigated. Tissue levels of RES were studied after i.v. and oral administration of trans-resveratrol (t-RES) to rabbits, rats, and mice. Half-life of RES in plasma, after i.v. administration of 20 mg t-RES/kg b.wt., was very short (e.g., 14.4 min in rabbits). The highest concentration of RES in plasma, either after i.v. or oral administration (e.g., 2.6 +/- 1.0 microM in mice 2.5 min after receiving 20 mg t-RES/kg orally), was reached within the first 5 min in all animals studied. Extravascular levels (brain, lung, liver, and kidney) of RES, which paralleled those in plasma, were always1 nmol/g f…
L-NAME induces direct arteriolar leukocyte adhesion, which is mainly mediated by angiotensin-II.
2005
Acute inhibition (1 h) of nitric oxide synthase (NOS) with L-NAME causes leukocyte recruitment in the rat mesenteric postcapillary venules that is angiotensin-II (Ang-II) dependent. Since 4-h exposure to Ang-II provokes arteriolar leukocyte adhesion, this study was designed to investigate whether subacute (4-h) NOS inhibition also causes this effect.Rats were intraperitoneally injected with saline, L-NAME, or 1H-[1,2,4]-oxidazolol-[4,3-a]-quinoxalin-1-one (ODQ). Leukocyte accumulation in the mesenteric microcirculation was examined 4 h later via intravital microscopy. Some groups were pretreated with losartan, an AT(1) Ang-II receptor antagonist.At 4-h, L-NAME caused a significant increase …
Molecular basis of endothelial dysfunction in sepsis.
2003
Sepsis is one of the major causes of mortality in critically ill patients and develops as a result of the host response to infection. A complex network of events is set into motion in the body by the infection and results in the pathogenesis of sepsis. This review article focuses on the molecular mechanisms and components involved in the pathogenesis of sepsis with a major emphasis on the endothelium. This includes sepsis-inducing bacterial components (e.g. endotoxins), cellular targets of these molecules and their responses, host reactions, intracellular and cytokine networks, individual susceptibility and new therapeutic targets in sepsis treatment.
A "double hit" murine model for schizophrenia shows alterations in the structure and neurochemistry of the medial prefrontal cortex and the hippocamp…
2013
Both alterations in neurodevelopment and aversive experiences during childhood and adolescence seem important risk factors for schizophrenia. Animal models reproducing these alterations mimic some of the symptoms, constituting a valid approach to study the etiopathology of this disorder. Among these models, the perinatal injection of N-methyl-d-aspartate receptor antagonists and the postweaning social isolation rearing are among the most widely used. Our aim is to combine them in a "double hit" model, which should produce a wider spectrum of alterations. Lister Hooded rats have been subjected to a single injection of MK-801 at postnatal day 7 and socially isolated from postweaning to adulth…
Non-granule PSA-NCAM immunoreactive neurons in the rat hippocampus
2002
The polysialylated form of the neural cell adhesion molecule (PSA-NCAM) continues to be expressed in the adult hippocampus, mainly in a subset of neurons located in the innermost portion of the granule cell layer. PSA-NCAM immunoreactive neurons have also been described outside this layer in humans, where they are severely reduced in schizophrenic brains. Given this important clinical implication, we were interested in finding whether similar neurons existed in the adult rat hippocampus and to characterize their distribution, morphology and phenotype. PSA-NCAM immunocytochemistry reveals labeled neurons in the subiculum, fimbria, alveus, hilus, and stratum oriens, lucidum and radiatum of CA…
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…