Search results for "Postsynaptic potential"

Autoradiographische Beobachtungen �ber den Einbau von3H-Uridin in herpesinduzierten Riesenzellen

1968

Cytological studies indicate that Herpes induced polykaryocytes often contain normal appearing nuclei. Further, virus induced DNA-synthesis was absent in about 20% of the nuclei inside of giant cells as observed by autoradiography. On the other hand, RNA-synthesis seems to be inhibited in all nuclei of such cells as evidenced by reduced3H-uridin incorporation. It is concluded that nuclear RNA-synthesis is blocked by spreading of inhibitory factors.

Chapter 6: Swelling of C6 glioma cells and astrocytes from glutamate, high K+ concentrations or acidosis

1992

Publisher Summary With impaired energy supply, cell swelling results from the failure of Na+/K+-ATPase according to the pump-leak model of cell volume regulation. In a series of in vitro studies, glial cell volume changes during defined and strictly controlled alterations of the extracellular environment in vitro. Experiments were performed with C6 glioma cells and astrocytes from primary culture. The major advantages of using C6 cells are the rapid availability of large cell numbers necessary for reliable flow cytometric volume measurements, and the homogeneous cell size distribution permitting the detection of even subtle volume changes. The sodium-potassium pump was blocked by the cardia…

Coincident glutamatergic depolarizations enhance GABAA receptor-dependent Cl- influx in mature and suppress Cl- efflux in immature neurons

2020

AbstractThe impact of GABAergic transmission on neuronal excitability depends on the Cl−-gradient across membranes. However, the Cl−-fluxes through GABAA receptors alter the intracellular Cl− concentration ([Cl−]i) and in turn attenuate GABAergic responses, a process termed ionic plasticity. Recently it has been shown that coincident glutamatergic inputs significantly affect ionic plasticity. Yet how the [Cl−]i changes depend on the properties of glutamatergic inputs and their spatiotemporal relation to GABAergic stimuli is unknown. To investigate this issue, we used compartmental biophysical models of Cl− dynamics simulating either a simple ball-and-stick topology or a reconstructed immatu…

Stereospecific interaction of bicuculline with specific [3H]strychnine binding to rat spinal cord synaptosomal membranes

1980

The gamma-aminobutyric acid (GABA) antagonist (+/-)-bicuculline inhibits specific [3H]strychnine binding to postsynaptic glycine receptor sites in rat spinal cord synaptosomal membranes with an inhibition constant of about 5 microM, which is fairly similar to its inhibition constant reported for the GABA receptor. This effect is highly stereospecific, since the affinity of (-)-bicuculline for the specific [3H]strychnine binding sites is more than ten times less than that of the pharmacologically active (+)-bicuculline. Besides an unspecific effect at the glycine receptor, the results could suggest that the glycine and the GABA receptors are located close together in spinal cord membranes, s…

HLA-G and MIC expression in tumors and their role in anti-tumor immunity.

2003

Non-classical MHC class Ib molecules have attracted growing interest in recent years, especially because they interact with non-T-cell inhibitory or triggering receptors expressed on natural killer (NK) and T cells, suggesting that they have a role in immune recognition. Abnormalities in MHC class Ib expression are frequently found in human tumors of various histologies and might be associated with poor clinical outcome despite the local accumulation of immune competent cells. Available data suggest that the balance between activating and suppressing signals significantly influences the efficacy of the immune response and consequently of tumor progression.

Author response: Inhibitory activities of short linear motifs underlie Hox interactome specificity in vivo

2015

Early Social Isolation Stress and Perinatal NMDA Receptor Antagonist Treatment Induce Changes in the Structure and Neurochemistry of Inhibitory Neuro…

2017

AbstractThe exposure to aversive experiences during early life influences brain development and leads to altered behavior. Moreover, the combination of these experiences with subtle alterations in neurodevelopment may contribute to the emergence of psychiatric disorders, such as schizophrenia. Recent hypotheses suggest that imbalances between excitatory and inhibitory (E/I) neurotransmission, especially in the prefrontal cortex and the amygdala, may underlie their etiopathology. In order to understand better the neurobiological bases of these alterations, we studied the impact of altered neurodevelopment and chronic early-life stress on these two brain regions. Transgenic mice displaying fl…

Development of the GABAergic system from birth to adolescence.

2011

The neurotransmitter GABA (γ-aminobutyric acid), acting via inotropic GABAA and metabotropic GABAB receptors, plays an essential role in a variety of distinct neuronal processes, including regulation of neuronal excitability, determination of temporal aspects of spike trains, control of the size and propagation of neuronal assemblies, generation of oscillatory activity, and neuronal plasticity. Although the developmental switch between excitatory and inhibitory GABAA receptor–mediated responses is widely appreciated, the fact that the postnatal maturation of the GABAergic system lasts until late adolescence is not so persuasively promoted. This review summarizes recent knowledge of the mat…

Lack of APP and APLP2 in GABAergic Forebrain Neurons Impairs Synaptic Plasticity and Cognition.

2020

AbstractAmyloid-β precursor protein (APP) is central to the pathogenesis of Alzheimer’s disease, yet its physiological functions remain incompletely understood. Previous studies had indicated important synaptic functions of APP and the closely related homologue APLP2 in excitatory forebrain neurons for spine density, synaptic plasticity, and behavior. Here, we show that APP is also widely expressed in several interneuron subtypes, both in hippocampus and cortex. To address the functional role of APP in inhibitory neurons, we generated mice with a conditional APP/APLP2 double knockout (cDKO) in GABAergic forebrain neurons using DlxCre mice. These DlxCre cDKO mice exhibit cognitive deficits i…

mGluR control of interneuron output regulates feedforward tonic GABAA inhibition in the visual thalamus

2011

Metabotropic glutamate receptors (mGluRs) play a crucial role in regulation of phasic inhibition within the visual thalamus. Here we demonstrate that mGluR-dependent modulation of interneuron GABA release results in dynamic changes in extrasynaptic GABAA receptor (eGABAAR)-dependent tonic inhibition in thalamocortical (TC) neurons of the rat dorsal lateral geniculate nucleus (dLGN). Application of the group I selective mGluR agonist dihydroxyphenylglycine produces a concentration-dependent enhancement of both IPSC frequency and tonic GABAA current (IGABAtonic) that is due to activation of both mGluR1a and mGluR5 subtypes. In contrast, group II/III mGluR activation decreases both IPSC freque…