Search results for "aspartate"
showing 10 items of 195 documents
D1/D5 modulation of synaptic NMDA receptor currents.
2009
Converging evidence suggests that salience-associated modulation of behavior is mediated by the release of monoamines and that monoaminergic activation of D1/D5receptors is required for normal hippocampal-dependent learning and memory. However, it is not understood how D1/D5modulation of hippocampal circuits can affect salience-associated learning and memory. We have observed in CA1 pyramidal neurons that D1/D5receptor activation elicits a bidirectional long-term plasticity of NMDA receptor-mediated synaptic currents with the polarity of plasticity determined by NMDA receptor, NR2A/B subunit composition. This plasticity results in a decrease in the NR2A/NR2B ratio of subunit composition. Sy…
Validation of clinical scoring systems ART and ABCR after transarterial chemoembolization of hepatocellular carcinoma.
2016
Abstract Purpose To perform an external validation of the Assessment for Retreatment with Transarterial Chemoembolization (ART) and α-fetoprotein (AFP), Barcelona Clinic Liver Cancer (BCLC), Child–Pugh, and response (ABCR) scores and to compare them in terms of prognostic power. Materials and Methods From 2000 to 2015, 871 patients with hepatocellular carcinoma underwent transarterial chemoembolization at a tertiary referral hospital, and 176 met all inclusion and exclusion criteria for both scores and were analyzed. Nineteen percent (n = 34) had BCLC stage A disease and 81% had stage B disease. Thirty-nine patients (22%) presented with elevated AFP levels. Overall survival was calculated. …
Functional Synaptic Projections onto Subplate Neurons in Neonatal Rat Somatosensory Cortex
2002
Subplate neurons (SPn) play an important role in the formation of thalamocortical connections during early development and show glutamatergic and GABAergic spontaneous synaptic activity. We characterized these synaptic inputs by performing whole-cell recordings from SPn in somatosensory cortical slices of postnatal day 0-3 rats. At -70 mV, electrical stimulation of the thalamocortical afferents elicited in 68% of the SPn a monosynaptic CNQX-sensitive postsynaptic current (PSC). These fast PSCs were mediated by AMPA receptors, because they were prolonged by cyclothiazide and blocked by GYKI 52466. On membrane depolarization, thalamocortical stimulation elicited in 50% of the cells an additio…
Patterns of liver injury in COVID-19 - a German case series.
2020
BACKGROUND: Reports of liver injury in patients with novel coronavirus disease 2019 (COVID-19) are emerging from China and the USA. A wide variety of liver function test abnormalities and few cases of severe liver failure have been reported. No data on the hepatic phenotype from Europe are available at current. METHODS: We report a case series of 44 consecutive patients hospitalized for COVID-19 in Germany. RESULTS: At the time of admission, aspartate aminotransferase greater than the upper limit of normal was present in 70%, while alanine aminotransferase was elevated in 15.8%. Markers of cholestatic liver injury were altered only in a minority of patients. During hospitalization, 31% and …
Exogenous t-PA Administration Increases Hippocampal Mature BDNF Levels. Plasmin- or NMDA-Dependent Mechanism?
2014
International audience; Brain-derived neurotrophic factor (BDNF) through TrkB activation is central for brain functioning. Since the demonstration that plasmin is able to process pro-BDNF to mature BDNF and that these two forms have opposite effects on neuronal survival and plasticity, a particular attention has been paid to the link between tissue plasminogen activator (tPA)/plasmin system and BDNF metabolism. However, t-PA via its action on different N-methyl-D-aspartate (NMDA) receptor subunits is also considered as a neuromodulator of glutamatergic transmission. In this context, the aim of our study was to investigate the effect of recombinant (r)t-PA administration on brain BDNF metabo…
Neurosteroid modulation of the presynaptic NMDA receptors regulating hippocampal noradrenaline release in normal rats and those exposed prenatally to…
2003
Abstract Prenatal exposure to diazepam (DZ), a positive allosteric modulator of the γ-aminobutyric acidA (GABAA) receptor complex, exerts profound effects that become more evident during puberty and in many cases are sex-specific, suggesting that such exposure interferes with the activity of steroid hormones. Apart from their well known effects on the genome, the reduced metabolites of many steroid hormones also interact directly with membrane receptors, including those for N-methyl- d -aspartate (NMDA). In this study, we compared the effects of several neurosteroids on NMDA receptors from normal rats and those exposed in utero to DZ (1.25 mg/kg per day) from the 14th through the 20th day o…
Delineation of molecular pathway activities of the chronic antidepressant treatment response suggests important roles for glutamatergic and ubiquitin…
2017
AbstractThe aim of this study was to identify molecular pathways related to antidepressant response. We administered paroxetine to the DBA/2J mice for 28 days. Following the treatment, the mice were grouped into responders or non-responders depending on the time they spent immobile in the forced swim test. Hippocampal metabolomics and proteomics analyses revealed that chronic paroxetine treatment affects glutamate-related metabolite and protein levels differentially in the two groups. We found significant differences in the expression of N-methyl-d-aspartate receptor and neuronal nitric oxide synthase proteins between the two groups, without any significant alterations in the respective tra…
Oligodendrocyte precursor cells modulate the neuronal network by activity-dependent ectodomain cleavage of glial NG2.
2014
The role of glia in modulating neuronal network activity is an important question. Oligodendrocyte precursor cells (OPC) characteristically express the transmembrane proteoglycan nerve-glia antigen 2 (NG2) and are unique glial cells receiving synaptic input from neurons. The development of NG2+ OPC into myelinating oligodendrocytes has been well studied, yet the retention of a large population of synapse-bearing OPC in the adult brain poses the question as to additional functional roles of OPC in the neuronal network. Here we report that activity-dependent processing of NG2 by OPC-expressed secretases functionally regulates the neuronal network. NG2 cleavage by the α-secretase ADAM10 yields…
N-methyl-d-aspartate receptor expression during adult neurogenesis in the rat dentate gyrus.
2006
Abstract N -methyl- d -aspartate (NMDA) receptors play a crucial role in the regulation of neuronal development during embryogenesis and they also regulate the rate of neurogenesis and proliferation in the adult dentate gyrus. However, the mechanism by which they influence these processes is not fully understood. NMDA receptors seem to be functional in hippocampal precursor cells and recently generated granule neurons, although there is no anatomical correlate of these physiological observations. We have analyzed the expression of the NMDA receptor subunits NR1 and NR2B in precursor cells and recently generated granule neurons of the adult rat dentate gyrus, using 5′bromodeoxyuridine, green…
Lateral habenula and hippocampal units: electrophysiological and iontophoretic study
1995
In previous works we studied, on cats, the effects of lateral habenula (LH) stimulation on hippocampal units. In particular, the results showed an excitation or an inhibition in relation to the stimulation frequency (0.5-3.0 Hz or 5.0-20 Hz, respectively). All the LH stimulation effects were antagonised by iontophoretic intrahippocampal application of methysergide (MS). In this series of experiments it was possible to demonstrate, on rats, that LH stimulation causes an excitatory effect in a major number of hippocampal units in relation to the frequency increase. The inhibitory effect by iontophoretic serotonine application and the reversible blockade of habenular modulation after iontophor…