Search results for "MDA"
showing 10 items of 275 documents
Action of anticonvulsants on hippocampal slices in Mg-free medium
1989
The effects of six prototype anticonvulsant drugs were investigated on epileptiform field potential discharges evoked in hippocampal slices of rats by removing magnesium ions from the perfusion fluid in order to reveal a possible interaction with N-methyl-D-aspartate (NMDA) receptor activation. All drugs reduced the multiple discharges with the following order of potency: midazolam greater than carbamazepine = phenytoin = phenobarbital greater than ethosuximide = valproate. They had a stronger depressant effect on the later population spikes but none of them abolished the epileptiform discharge. These effects can be explained by known mechanisms of action of the anticonvulsants tested and l…
Redox signaling in acute pancreatitis
2015
Acute pancreatitis is an inflammatory process of the pancreatic gland that eventually may lead to a severe systemic inflammatory response. A key event in pancreatic damage is the intracellular activation of NF-κB and zymogens, involving also calcium, cathepsins, pH disorders, autophagy, and cell death, particularly necrosis. This review focuses on the new role of redox signaling in acute pancreatitis. Oxidative stress and redox status are involved in the onset of acute pancreatitis and also in the development of the systemic inflammatory response, being glutathione depletion, xanthine oxidase activation, and thiol oxidation in proteins critical features of the disease in the pancreas. On th…
Changes in NMDA-receptor function in the first week following laser-induced lesions in rat visual cortex.
2011
Focal brain injuries are accompanied by processes of functional reorganization that partially compensate the functional loss. In a previous study, extracellular recordings at the border of a laser-induced lesion in the visual cortex of rats showed an enhanced synaptic plasticity, which was mediated by the activity of NR2B-contaning NMDA-receptors (NMDARs) shedding light on the potential cellular mechanisms underlying this reorganization. Given the potentially important contribution of NMDARs in processes of functional reorganization, in the present study, we used the same lesion model to further investigate lesion-induced changes in function and localization of NMDARs in the vicinity of the…
The role of N-methyl-D-asparate receptors in neurogenesis.
2006
The dentate gyrus continues to incorporate granule neurons during adulthood. Among the factors that we know modulate adult neurogenesis in the dentate gyrus, one of the first studied was the influence of excitatory amino-acids. These neurotransmitters, acting through NMDA receptors, are able to modulate both the proliferation of progenitor cells as well as the rate of neurogenesis in the adult dentate gyrus. However, the mechanisms by which these processes are influenced are not clearly known. Although there is no anatomical evidence of NMDA receptor expression in adult hippocampal progenitor cells or differentiating granule neurons, electrophysiological data and in vitro studies suggest th…
Subplate Cells: Amplifiers of Neuronal Activity in the Developing Cerebral Cortex
2009
Due to their unique structural and functional properties, subplate cells are ideally suited to function as important amplifying units within the developing neocortical circuit. Subplate neurons have extensive dendritic and axonal ramifications and relatively mature functional properties, i.e. their action potential firing can exceed frequencies of 40 Hz. At earliest stages of corticogenesis subplate cells receive functional synaptic inputs from the thalamus and from other cortical and non-cortical sources. Glutamatergic and depolarizing GABAergic inputs arise from cortical neurons and neuromodulatory inputs arise from the basal forebrain and other sources. Activation of postsynaptic metabot…
Neurotoxicity in Rat Cortical Cells Caused by N-Methyl-D-Aspartate (NMDA) and gp120 of HIV-1: Induction and Pharmacological Intervention
1996
Incubation of highly enriched neurons from rat cerebral cortex with the human immunodeficiency virus type 1 (HIV-1) coat protein gpl20 for 18 h results in fragmentation of DNA at internucleosomal linkers, a feature of apoptosis. We report that neurons respond to exposure to gp120 with an increased release of arachidonic acid via activation of phospholipase A2. This process is not inhibited by antagonists of the N-methyl-D-aspartate (NMDA) receptor channels. To investigate the influence of arachidonic acid on the sensitivity of NMDA receptor towards its aganist, low concentrations of NMDA were coadministered with arachidonic acid. Under these conditions the NMDA-mediated cytotoxicity was enh…
Ketamine’s Effects on the Glutamatergic and GABAergic Systems: A Proteomics and Metabolomics Study in Mice
2018
Ketamine, a noncompetitive, voltage-dependent N-Methyl-D-aspartate receptor (NMDAR) antagonist, has been shown to have a rapid antidepressant effect and is used for patients experiencing treatment-resistant depression. We carried out a time-dependent targeted mass spectrometry-based metabolomics profiling analysis combined with a quantitative based on in vivo <sup>15</sup>N metabolic labeling proteome comparison of ketamine- and vehicle-treated mice. The metabolomics and proteomics datasets were used to further elucidate ketamine’s mode of action on the gamma-aminobutyric acid (GABA)ergic and glutamatergic systems. In addition, myelin basic protein levels were analyzed by Wester…
Traditional Chinese herbal medicine at the forefront battle against COVID-19: Clinical experience and scientific basis.
2020
Abstract Background Throughout the 5000-year history of China, more than 300 epidemics were recorded. Traditional Chinese herbal medicine (TCM) has been used effectively to combat each of these epidemics’ infections, and saved many lives. To date, there are hundreds of herbal TCM formulae developed for the purpose of prevention and treatment during epidemic infections. When COVID-19 ravaged the Wuhan district in China in early January 2020, without a deep understanding about the nature of COVID-19, patients admitted to the TCM Hospital in Wuhan were immediately treated with TCM and reported later with >90% efficacy. Approach We conducted conduct a systematic survey of various TCM herbal pre…
Klasicisms un romantisms franču glezniecībā pēc Rīgas un Jelgavas muzeju gleznām: studiju darbs
1933
New bradorid arthropods from the Lower Cambrian of Spain
2007
Lower Early Cambrian rocks of the Pedroche Formation in the Sierra de Cordoba consist of well-exposed mixed facies with abundant fossil assemblages showing long stratigraphical ranges. These assemblages include diverse Ovetian archaeocyaths, trilobites, small shelly fossils, calcimicrobia, trace fossils, and stromatolites. For the ostracod-like Cambriidae it is the first record from the Iberian Peninsula. Cordubiella pedrochensis n.gen. n.sp. comes from two sections of the lower Pedroche Formation: the Arroyo de Pedroche 1 sec- tion, and the Arroyo Pedroche 2 section. The material was collected in the zone of Lemdadella perejoni, of lower Ovetian age and below the Eoredlichia FAD. It supple…