Search results for "gamma-Aminobutyric Acid"
showing 10 items of 142 documents
Pre- and postsynaptic type-1 cannabinoid receptors control the alterations of glutamate transmission in experimental autoimmune encephalomyelitis
2013
Type-1 cannabinoid receptors (CB1R) are important regulators of the neurodegenerative damage in multiple sclerosis (MS) and in experimental autoimmune encephalomyelitis (EAE). In GABAergic striatal neurons, CB1R stimulation exerts protective effects by limiting inflammation-induced potentiation of glutamate-mediated spontaneous excitatory postsynaptic currents (sEPSCs). Here we show that CB1R located on GABAergic or on glutamatergic neurons are differentially involved in the pre- and postsynaptic alterations of sEPSCs caused by EAE in the striatum. After induction of EAE, mice selectively lacking CB1R on GABAergic neurons (GABA-CB1R-KO) showed exacerbated alterations of sEPSC duration in GA…
The GABAergic System and the Gastrointestinal Physiopathology.
2015
Since the first report about the presence of γ-aminobutyric acid (GABA) within the gastrointestinal (GI) tract, accumulating evidence strongly supports the widespread representation of the GABAergic system in the enteric milieu, underlining its potential multifunctional role in the regulation of GI functions in health and disease. GABA and GABA receptors are widely distributed throughout the GI tract, constituting a complex network likely regulating the diverse GI behaviour patterns, cooperating with other major neurotransmitters and mediators for maintaining GI homeostasis in physiologic and pathologic conditions. GABA is involved in the circuitry of the enteric nervous system, controlling…
Transporter-mediated replacement of extracellular glutamate for GABA in the developing murine neocortex
2013
During early development, cortical neurons migrate from their places of origin to their final destinations where they differentiate and establish synaptic connections. During corticogenesis, radially migrating cells move from deeper zone to the marginal zone, but they do not invade the latter. This "stop" function of the marginal zone is mediated by a number of factors, including glutamate and γ-aminobutyric acid (GABA), two main neurotransmitters in the central nervous system. In the marginal zone, GABA has been shown to be released via GABA transporters (GAT)-2/3, whereas glutamate transporters (EAATs) operate in the uptake mode. In this study, GABAergic postsynaptic currents (GPSCs) were…
The inhibitory neural circuitry as target of antiepileptic drugs.
2001
Impairments and defects in the inhibitory neurotransmission in the CNS can contribute to various seizure disorders, i.e., gamma-aminobutyric acid (GABA) and glycine as the main inhibitory neurotransmitters in the brain play a crucial role in some forms of epilepsy. Recent advances in deciphering the molecular basis of the GABAergic and glycinergic systems has been achieved by means of cloning techniques and gene targeting strategies in animals, contributing to the understanding of drug action. As well, several anticonvulsive substances emerged which target key molecules of the inhibitory systems. Employment of recombinant expression systems, including, but not restricted to the inhibitory c…
GABA transporters control GABAergic neurotransmission in the mouse subplate.
2015
The subplate is a transient layer between the cortical plate and intermediate zone in the developing cortex. Thalamo-cortical axons form temporary synapses on subplate neurons (SPns) before invading the cortical plate. Neuronal activity within the subplate is of critical importance for the development of neocortical circuits and architecture. Although both glutamatergic and GABAergic inputs on SPns were reported, short-term plasticity of GABAergic transmission has not been investigated yet. GABAergic postsynaptic currents (GPSCs) were recorded from SPns in coronal neocortical slices prepared from postnatal day 3-4 mice using whole-cell patch-clamp technique. Evoked GPSCs (eGPSCs) elicited b…
Effects of GABA-transporter (GAT) inhibitors on rat behaviour in open-field and elevated plus-maze.
1999
The behavioural consequences of inhibition of gamma-aminobutyric acid (GABA) uptake were studied. Two GABA uptake inhibitors, tiagabine and SKF 89976-A, were administered to rats, and behaviour was analysed 30 min later in a standard open field, an enriched open field, and an elevated plus-maze. Eight groups of animals received either saline (0.9%), tiagabine, or SKF 89976-A. At a dose of 18.5 mg/kg, tiagabine, an established antiseizure drug, impaired motor coordination, enhanced exploratory activity and reduced anxiety related behaviour. SKF 89976-A exhibited minimal effects over the dose range tested. These results indicate that inhibition of GABA uptake might be a pharmacological strate…
Functional evidence for GABA as modulator of the contractility of the longitudinal muscle in mouse duodenum: Role of GABAA and GABAC receptors
2007
We investigated, in vitro, the effects of gamma-aminobutyric acid (GABA) on the spontaneous mechanical activity of the longitudinal smooth muscle in mouse duodenum. GABA induced an excitatory effect, consisting in an increase in the basal tone, which was antagonized by the GABA(A)-receptor antagonist, bicuculline, potentiated by (1,2,5,6-Tetrahydropyridin-4-yl)methylphosphinic acid hydrate (TPMPA), a GABA(C)-receptor antagonist and it was not affected by phaclofen, a GABA(B)-receptor antagonist. Muscimol, GABA(A) receptor agonist, induced a contractile effect markedly reduced by bicuculline, tetrodotoxin (TTX), hexamethonium and atropine. Cis-4-aminocrotonic acid (CACA), a specific GABA(C) …
Age-related differences of γ-aminobutyric acid (GABA)ergic transmission in human colonic smooth muscle.
2021
Background: Enteric neurons undergo to functional changes during aging. We investigated the possible age-associated differences in enteric γ-aminobutyric acid (GABA)ergic transmission evaluating function and distribution of GABAergic receptors in human colon. Methods: Mechanical responses to GABA and GABA receptor agonists on slow phasic contractions were examined in vitro as changes in isometric tension in colonic muscle strips from young (<65 years old) and aged patients (>65 years old). GABAergic receptor expression was assessed by quantitative RT-PCR. Key Results: In both preparations GABA induced an excitatory effect, consisting in an increase in the basal tone, antagonized by th…
The diversity of GABAA receptors. Pharmacological and electrophysiological properties of GABAA channel subtypes.
1998
The amino acid gamma-aminobutyric-acid (GABA) prevails in the CNS as an inhibitory neurotransmitter that mediates most of its effects through fast GABA-gated Cl(-)-channels (GABAAR). Molecular biology uncovered the complex subunit architecture of this receptor channel, in which a pentameric assembly derived from five of at least 17 mammalian subunits, grouped in the six classes alpha, beta, gamma, delta, sigma and epsilon, permits a vast number of putative receptor isoforms. The subunit composition of a particular receptor determines the specific effects of allosterical modulators of the GABAARs like benzodiazepines (BZs), barbiturates, steroids, some convulsants, polyvalent cations, and et…
Long-Term Behavioral Programming Induced by Peripuberty Stress in Rats Is Accompanied by GABAergic-Related Alterations in the Amygdala
2014
Stress during childhood and adolescence is a risk factor for psychopathology. Alterations in γ-aminobutyric acid (GABA), the main inhibitory neurotransmitter in the brain, have been found following stress exposure and fear experiences and are often implicated in anxiety and mood disorders. Abnormal amygdala functioning has also been detected following stress exposure and is also implicated in anxiety and social disorders. However, the amygdala is not a unitary structure; it includes several nuclei with different functions and little is known on the potential differences the impact of early life stress may have on this system within different amygdaloid nuclei. We aimed here to evaluate pote…