Search results for "AMPA"

Contribution à l'étude des « goûts de lumière » dans le vin de champagne. II. Influence de la lumière sur le potentiel d'oxydoreduction. Corrélation …

1978

<p style="text-align: justify;">Les auteurs déterminent les potentiels d'oxydoréduction de nombreux vins de champagne avant et après la prise de mousse. Ils précisent la relation, par éclairement de vins dégorgés et non dégorgés, entre l'apparition de « goût de lumière » et le potentiel d'oxydoréduction. Ils donnent les longueurs d'onde responsables des « goûts de lumière ».</p><p style="text-align: justify;">+++</p><p style="text-align: justify;">The oxydoreduction potentials are determined for a number of wines of champagne before and after the second prise de mousse fermentation. By illuminating disgorged and non disgorged wines, the authors of this article …

I 🌹🍀🇫🇮 You! : Emojis as Emotional-Political Signifiers in Finnish Election Campaign Discussion Online

2023

Social media platforms and the forms of vernacular expression they support invite citizens to emotionally react to political content. This study focuses on the affective networks of emoji use in the Facebook comment threads on 18 politicians’ public pages before the Finnish 2019 parliamentary elections. We aim to generate a holistic understanding of the use of emojis in campaign communications while providing a more profound understanding of the affective practices emerging in specific contexts, such as in relation to particular political actors. We analyze the data using computational methods and network analysis and complement this with qualitative analysis. The results indicate that emoj…

Kampania wyborcza w prasie regionalnej na przykładzie "Nowej Trybuny Opolskiej"

2016

Special Features of the Hippocampal Formation with Respect to Seizure Conditions

1987

The hippocampus has long been known as a region particularly prone to epileptiform discharges (Kandel et al. 1961). Connections and physiology of this archaic cortical structure are relatively well charac-terized and a wealth of information on features favoring exaggerated neuronal activity has emerged in recent years. The lamellar organization of the hippo-campus (Andersen et al. 1971) may be one of these features; it certainly has facilitated their investigation. Tissue slices cut along the lamellae, perpendicular to the axis of the structure, contain a relatively undisturbed chain of neurons which can be rigorously investigated in vitro. The results from such experiments have allowed mod…

Neurobiology

2016

In the adult mammalian brain, neurogenesis occurs in the dentate gyrus (DG) of the hippocampus throughout the life span. Neurogenesis has been extensively characterized in rodents and to a lesser extent in primates. Within the hippocampus, the adult neurogenic niche is specifically located in the subgranular zone of the DG, where neural stem/progenitor cells (NSPCs) reside. It has been confirmed that these stem cells, which possess astrocytic features, give rise to intermediate progenitors, immature neurons, and neurons. The NSPCs have radial glia-like morphology and electrolucid cytoplasm, in contrast to the immature neurons whose cytoplasm is electrodense, containing abundant polyribosome…

TMS-EEG signatures of glutamatergic neurotransmission in human cortex

2019

AbstractNeuronal activity in the brain is regulated by an excitation-inhibition balance. Glutamate is the main excitatory neurotransmitter. Transcranial magnetic stimulation (TMS) evoked electroencephalographic (EEG) potentials (TEPs) represent a novel way to quantify pharmacological effects on neuronal activity in the human cortex. Here we tested TEPs under the influence of a single oral dose of two anti-glutamatergic drugs, perampanel, an AMPA-receptor antagonist, and dextromethorphan, an NMDA-receptor antagonist, and nimodipine, an L-type voltage-gated calcium channel blocker in 16 healthy adults in a pseudorandomized, double-blinded, placebo-controlled, crossover design. Single-pulse TM…

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…

Age-related changes in the endocannabinoid system in the mouse hippocampus.

2015

Previous studies have demonstrated that the endocannabinoid system significantly influences the progression of brain ageing, and the hippocampus is one of the brain regions most vulnerable to ageing and neurodegeneration. We have further examined age-related changes in the hippocampal endocannabinoid system by measuring the levels of anandamide (AEA) and 2-arachidonoylglycerol (2-AG) in young and old mice from two different mouse strains. We found a decrease in 2-AG but not AEA levels in aged mice. In order to identify the cause for 2-AG level changes, we investigated the levels of several enzymes that contribute to synthesis and degradation of 2-AG in the hippocampus. We found a selective …

Altered receptor binding densities in experimental antiphospholipid syndrome despite only moderately enhanced autoantibody levels and absence of beha…

2013

Abstract Experimental antiphospholipid syndrome (eAPS) in Balb/c mice causes neuropsychiatric abnormalities including hyperactivity, increased explorative behavior and cognitive deficits. Recently, we have demonstrated that these behavioral changes were linked to an upregulation of serotonergic 5-HT1A receptor binding densities in cortical and hippocampal regions while excitatory and inhibitory neurotransmitter receptors remain largely unchanged. To examine whether the observed behavioral features depend on a critical antibody concentration, mice with only moderately enhanced antiphospholipid antibodies (aPL), about 50–80% of high levels, were analyzed and compared to controls. The staircas…

Compensatory mechanisms enhance hippocampal acetylcholine release in transgenic mice expressing human acetylcholinesterase

2001

Central cholinergic neurotransmission was studied in learning-impaired transgenic mice expressing human acetylcholinesterase (hAChE-Tg). Total catalytic activity of AChE was approximately twofold higher in synaptosomes from hippocampus, striatum and cortex of hAChE-Tg mice as compared with controls (FVB/N mice). Extracellular acetylcholine (ACh) levels in the hippocampus, monitored by microdialysis in the absence or presence of 10(-8)-10(-3) M neostigmine in the perfusion fluid, were indistinguishable in freely moving control and hAChE-Tg mice. Muscarinic receptor functions were unchanged as indicated by similar effects of scopolamine on ACh release and of carbachol on inositol phosphate fo…