Encontrados 21 documentos, a visualizar página 1 de 3
Oligodendrogenesis from neural stem cells: Perspectives for remyelinating strat...
Grade, Sofia; Bernardino, Liliana; Malva, João O.Mobilization of remyelinating cells spontaneously occurs in the adult brain. These cellular resources are specially active after demyelinating episodes in early phases of multiple sclerosis (MS). Indeed, oligodendrocyte precursor cells (OPCs) actively proliferate, migrate to and repopulate the lesioned areas. Ultimately, efficient remyelination is accomplished when new oligodendrocytes reinvest nude neuronal ax...
Tumor necrosis factor-alpha modulates survival, proliferation, and neuronal dif...
Bernardino, Liliana; Agasse, Fabienne; Silva, Bruno; Ferreira, Raquel; Grade, Sofia; Malva, João O.Tumor necrosis factor (TNF)- has been reported to modulate brain injury, but remarkably, little is known about its effects on neurogenesis. We report that TNF- strongly influences survival, proliferation, and neuronal differentiation in cultured subventricular zone (SVZ) neural stem/progenitor cells derived from the neonatal P1-3 C57BL/6 mice. By using single-cell calcium imaging, we developed a method, based o...
Inflammatory events in hippocampal slice cultures prime neuronal susceptibility...
Bernardino, Liliana; Balosso, Silvia; Ravizza, Teresa; Marchi, Nicola; Ku, George; Randle, John C.; Malva, João O.; Vezzani, AnnamariaWe investigated the consequences of transient application of specific stimuli mimicking inflammation to hippocampal tissue on microglia activation and neuronal cell vulnerability to a subsequent excitotoxic insult. Two-week-old organotypic hippocampal slice cultures, from 7-day-old C57BL/6 donor mice, were exposed for 3 h to lipopolysaccharide (LPS; 10 ng/mL) followed by 3 h co-incubation with 1 mM ATP, or 100 ...
Protein kinase C activity blocks neuropeptide Y-mediated inhibition of glutamat...
Silva, Ana P.; Lourenço, Joana; Xapelli, Sara; Ferreira, Raquel; Kristiansen, Heidi; Woldbye, David P. D.; Oliveira, Catarina R.; Malva, João O.The unbalanced excitatory/inhibitory neurotransmitter function in the neuronal network afflicted by seizures is the main biochemical and biophysical hallmark of epilepsy. The aim of this work was to identify changes in the signaling mechanisms associated with neuropeptide Y (NPY)-mediated inhibition of glutamate release that may contribute to hyperexcitability. Using isolated rat hippocampal nerve terminals, we...
Phytochemical and antioxidant characterization of Hypericum perforatum alcoholi...
Silva, Bruno A.; Ferreres, Federico; Malva, João O.; Dias, Alberto C. P.The antioxidant potentials of a total ethanolic extract of Hypericum perforatum (TE) and fractions were evaluated and correlated with their phenolic contents. The extracts were fully characterised by HPLC-DAD-MS-MS. Kaempferol 3-rutinoside and rutin-acetyl were identified for the first time in TE extracts. The free radical-scavenging properties of TE (EC50=21 [mu]g dwb/ml) and fractions were studied using DPPH....
Up-regulation of neuropeptide Y levels and modulation of glutamate release thro...
Silva, Ana P.; Xapelli, Sara; Pinheiro, Paulo S.; Ferreira, Raquel; Lourenço, Joana; Cristóvão, Armando; Grouzmann, Eric; Cavadas, CláudiaKainate-induced epilepsy has been shown to be associated with increased levels of neuropeptide Y (NPY) in the rat hippocampus. However, there is no information on how increased levels of this peptide might modulate excitation in kainate-induced epilepsy. In this work, we investigated the modulation of glutamate release by NPY receptors in hippocampal synaptosomes isolated from epileptic rats. In the acute phase...
Modulator effects of interleukin-1beta and tumor necrosis factor-alpha on AMPA-...
Bernardino, Liliana; Xapelli, Sara; Silva, Ana P.; Jakobsen, Birthe; Poulsen, Frantz R.; Oliveira, Catarina R.; Vezzani, Annamaria; Malva, João O.The inflammatory cytokines interleukin-1\u2424 and tumor necrosis factor-\u2423 (TNF-\u2423) have been identified as mediators of several forms of neurodegeneration in the brain. However, they can produce either deleterious or beneficial effects on neuronal function. We investigated the effects of these cytokines on neuronal death caused by exposure of mouse organotypic hippocampal slice cultures to toxic conce...
Presynaptic kainate receptors modulating glutamatergic transmission in the rat ...
Cunha, Rodrigo A.; Ribeiro, J. A.; Malva, João O.Kainate receptors are ionotropic glutamate receptors located postsynaptically, mediating frequency-dependent transmission, and presynaptically, modulating transmitter release. In contrast to the excitatory postsynaptic kainate receptors, presynaptic kainate receptor can also be inhibitory and their effects may involve a metabotropic action. Arachidonic acid (AA) modulates most ionotropic receptors, in particula...
Subcellular localization of adenosine A1 receptors in nerve terminals and synap...
Rebola, Nelson; Pinheiro, Paulo C.; Oliveira, Catarina R.; Malva, João O.; Cunha, Rodrigo A.Adenosine is a neuromodulator in the CNS that mainly acts through pre- and postsynaptic A1 receptors to inhibit the release of excitatory neurotransmitters and NMDA receptor function. This might result from a highly localized distribution of A1 receptors in the active zone and postsynaptic density of CNS synapses that we now investigated in the rat hippocampus. The binding density of the selective A1 receptor a...
Functional interaction between neuropeptide Y receptors and modulation of calci...
Silva, Ana P.; Carvalho, Arsélio P.; Carvalho, Caetana M.; Malva, João O.We investigated the functional interaction between neuropeptide Y (NPY) receptors using nerve terminals and cultured rat hippocampal neurons, and we evaluated the involvement of voltage-gated Ca2+ channels (VGCCs) in NPY receptors-induced inhibition of Ca2+ influx and glutamate release. The KCl-evoked release of glutamate from hippocampal synaptosomes was inhibited by 1 [mu]M NPY and this effect was insensitive...
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