Search results for " Glutamate"

A critical role for VEGF and VEGFR2 in NMDA receptor synaptic function and fear-related behavior

2016

Vascular endothelial growth factor (VEGF) is known to be required for the action of antidepressant therapies but its impact on brain synaptic function is poorly characterized. Using a combination of electrophysiological, single-molecule imaging and conditional transgenic approaches, we identified the molecular basis of the VEGF effect on synaptic transmission and plasticity. VEGF increases the postsynaptic responses mediated by the N-methyl-D-aspartate type of glutamate receptors (GluNRs) in hippocampal neurons. This is concurrent with the formation of new synapses and with the synaptic recruitment of GluNR expressing the GluN2B subunit (GluNR-2B). VEGF induces a rapid redistribution of Glu…

NovelAmycolatopsis balhimycinabiochemical abilities unveiled by proteomics

2014

Amycolatopsis balhimycina DSM5908 is an actinomycete producer of balhimycin, an analogue of vancomycin, the antibiotic of ‘last resort’ against multidrug-resistant Gram-positive pathogens. Most knowledge on glycopeptide biosynthetic pathways comes from studies on A. balhimycina as this strain, among glycopeptide producers, is genetically more amenable. The recent availability of its genome sequence allowed to perform differential proteomic analyses elucidating key metabolic pathways leading to antibiotic production in different growth conditions. To implement proteomic data on A. balhimycina derived from 2-DE approaches and to identify novel components, a combined approach based on protein …

Calcium signaling in plant defense: involvement of subcellular compartments and glutamate receptorsCalcium signaling in plant defense: involvement of…

2012

Dynamics of the ligand-binding domains of ionotropic glutamate receptors

2010

Sensory and Chemical Analysis of Fractions Obtained by Gel Permeation of Water-Soluble Comte Cheese Extracts

1995

The pure water extraction of Comte cheese solubles and their chromatographic separation facilitate sensory analysis experiments with the fractions directly collected from the column. Two extracts, one obtained after ultrafiltration, the other after chromatography on Sephadex G25, have been separated on Toyopearl HW-40S. The sensory evaluation of the obtained fractions shows in the two cases that some fractions have interesting flavors. However, physicochemical analysis shows that organoleptic characteristics are linked more to the presence of amino acids and salts than to the presence of peptides. Apart from monosodium glutamate, most of the amino acids are present in the fractions at conce…

A l-glutamate-responsive delivery system based on enzyme-controlled self-immolative arylboronate-gated nanoparticles

2019

We report herein a L-glutamate (L-Glu)-responsive delivery system. It consists of Janus Au–mesoporous silica (MS) nanoparticles functionalized with L-glutamate oxidase on the Au face and with self-immolative arylboronate derivatives as caps on the MS face. The MS face is additionally loaded with a cargo. The delivery paradigm is based on the recognition of L-Glu by the enzyme and the subsequent formation of H2O2, which induces the cleavage of the self-immolative gate and the uncapping of the pores. Given the importance of L-Glu as a key neurotransmitter, we hope that these findings will help in designing new therapeutic strategies for nervous system diseases.

Glutamatergic activation of hippocampal phospholipase D: postnatal fading and receptor desensitization.

2002

Abstract: Phospholipase D (PLD) activity was determined in rat hippocampal slices between postnatal days 3 and 35. After birth, basal PLD activity was low and, within 2 weeks, increased to reach a plateau that was maintained up to the adult age. Likewise the response to glutamate developed postnatally to reach a maximum at day 8, but then faded rapidly and was almost absent at day 35. Activation of PLD by 4β-phorbol 12β,13α-dibutyrate (PDB) was independent of age, whereas the effect of aluminum fluoride (AlF4−) increased to a plateau within the first week. At day 8, PLD stimulation by glutamate via metabotropic receptors involved protein kinase C activation, but was independent of Ca2+ infl…

Transient focal cerebral ischemia significantly alters not only EAATs but also VGLUTs expression in rats: relevance of changes in reactive astroglia

2010

The involvement of plasma membrane glutamate transporters (EAATs - excitatory aminoacid transporters) in the pathophysiology of ischemia has been widely studied, but little is known about the role of vesicular glutamate transporters (VGLUTs) in the ischemic process. We analyzed the expression of VGLUT1-3 in the cortex and caudate-putamen of rats subjected to transient middle cerebral artery occlusion. Western blot and immunohistochemistry revealed an increase of VGLUT1 signal in cortex and caudate-putamen until 3 days of reperfusion followed by a reduction 7 days after the ischemic insult. By contrast, VGLUT2 and 3 were drastically reduced. Confocal microscopy revealed an increase in VGLUT2…

The Dual Role of the GABAA Receptor in Peripheral Inflammation and Neuroinflammation: A Study in Hyperammonemic Rats

2021

Cognitive and motor impairment in minimal hepatic encephalopathy (MHE) are mediated by neuroinflammation, which is induced by hyperammonemia and peripheral inflammation. GABAergic neurotransmission in the cerebellum is altered in rats with chronic hyperammonemia. The mechanisms by which hyperammonemia induces neuroinflammation remain unknown. We hypothesized that GABAA receptors can modulate cerebellar neuroinflammation. The GABAA antagonist bicuculline was administrated daily (i.p.) for four weeks in control and hyperammonemic rats. Its effects on peripheral inflammation and on neuroinflammation as well as glutamate and GABA neurotransmission in the cerebellum were assessed. In hyperammone…

Modifications induced on the amygdaloid paroxysmal activity by entopeduncolar or nigral injection of kainic acid, in the cat.

1983

Entopeduncolar or nigral injection of kainic acid determines an early decrease of the evoked amygdaloid paroxysmal activity and a later increase of the after discharge duration. This biphasic effect is likely due to the structural analogy of the drug with monosodium glutamate, a neuroexcitant amino acid. The data suggest that the basal ganglia exert a tonic control on the amygdaloid activity.