Search results for "GABA Agents"
showing 9 items of 9 documents
Opposite role played by GABAA and GABAB receptors in the modulation of peristaltic activity in mouse distal colon.
2014
We investigated the role of GABA on intestinal motility using as model the murine distal colon. Effects induced by GABA receptors recruitment were examined in whole colonic segments and isolated circular muscle preparations to analyze their influence on peristaltic reflex and on spontaneous and neurally-evoked contractions. Using a modified Trendelenburg set-up, rhythmic peristaltic contractions were evoked by gradual distension of the colonic segments. Spontaneous and neurally-evoked mechanical activity of circular muscle strips were recorded in vitro as changes in isometric tension. GABA, at low concentrations (10-50 µM), potentiated peristaltic activity and the neural cholinergic contrac…
Non-Classical Transformation of Benzendiazonium Hydrogen Sulfates. Access to 1,3-Dimethylisochromeno[4,3-c]pyrazol-5(1H)-one, a Potential Benzodiazep…
2013
The compound 2-((1,3-dimethyl-1H-pyrazol-5-yl)(methyl)carbamoyl)benzene-diazonium hydrogen sulfate (10) was reacted with copper sulfate and sodium chloride, in the presence of ascorbic acid as reducing agent, to afford a mixture of the chlorinated epimers 4′-chloro-2,2′,5′-trimethyl-2′,4′-dihydrospiro[isoindoline-1,3′-pyrazol]-3-one (18) and (19), the epimers 4′-hydroxy-2,2′,5′-trimethyl-2′,4′-dihydrospiro[isoindoline-1,3′-pyrazol]-3-one (20) and (21), and N-(1,3-dimethyl-1H-pyrazol-5-yl)benzamide (22). Under the foregoing conditions, diazonium salt 10 affords neither the 2-chloro-N-(1,3-dimethyl-1H-pyrazol-5-yl)-N-methylbenzamide (23) nor the tricyclic derivative 24, the classical products…
Modulation of visual cortex excitability in migraine with aura: effects of valproate therapy.
2009
We explored the effects of valproate treatment on visual cortex excitability changes in migraine with aura patients. Abnormal cortical excitability has been suggested to play an important role in the etiopathogenesis of migraine; in particular, it has been suggested a failure of inhibitory circuits in migraine with aura. Valproate acts as a central GABA agonist and it is reasonable suppose that VPA could modify cortical excitability state. Phosphene threshold (PT) was assessed at baseline and after 1 Hz rTMS before and after one month therapy. We found that low-frequency rTMS in drug-free migraineurs decreased PT, while the treatment with the GABA agonist valproate is able to revert the eff…
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…
Temporal resolution and temporal transfer properties: gabaergic and cholinergic mechanisms.
2007
Temporal resolution is a basic property of the visual system and critically depends upon retinal temporal coding properties which are also of importance for directional coding. Whether the temporal coding properties for directional coding derive form inherent properties or critically depend upon the temporal coding mechanisms is unclear. Here, the influence of acetylcholine and GABA upon photopic temporal coding was investigated in goldfish, using flicker stimuli, in a behavioral and an electrophysiological (ERG) approach. The goldfish temporal resolution ability decreased from more than 90% correct choices at 20 Hz flicker frequency to about 65% at 45 Hz flicker frequency with a flicker fu…
(A,B) In vivo GCaMP6f signals recorded in layers M1, M5 and M9/10 of Mi1 (A) and Tm3 (B) neurons, before (blue, green) and after (gray, red) applicat…
2019
Sensory systems sequentially extract increasingly complex features. ON and OFF pathways, for example, encode increases or decreases of a stimulus from a common input. This ON/OFF pathway split is thought to occur at individual synaptic connections through a sign-inverting synapse in one of the pathways. Here, we show that ON selectivity is a multisynaptic process in the Drosophila visual system. A pharmacogenetics approach demonstrates that both glutamatergic inhibition through GluClα and GABAergic inhibition through Rdl mediate ON responses. Although neurons postsynaptic to the glutamatergic ON pathway input L1 lose all responses in GluClα mutants, they are resistant to a cell-type-specifi…
Preclinical evidence of new opioid modulators for the treatment of addiction.
2010
Addiction to opiates is one of the most severe forms of substance dependence, and despite a variety of pharmacological approaches to treat it, relapse is observed in a high percentage of subjects. New pharmacological compounds are necessary to improve the outcome of treatments and reduce adverse side effects. Moreover, drugs that act on the opioid system can also be of benefit in the treatment of alcohol or cocaine addiction. AREA COVERED BY THIS REVIEW: Recent preclinical studies of pharmacological agents for the treatment of opiate addiction (2008 to the present date).The reader will be informed of the latest drugs shown in animal models to modify dependence on opiates and the reinforcing…
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…
Behavioral analysis indicates benzodiazepine-tolerance mediated by the benzodiazepine binding-site at the GABA(A)-receptor.
2001
Abstract 1. GABA A -receptor induced changes in locomotion and anxiety-like behaviors were studied in rats using an open-field and an elevated plus-maze. Acute and chronic doses of the benzodiazepine diazepam without and in combination with the GABA uptake inhibitor SKF-89976A were investigated. 2. Fifty-six male rats of the strain PVG/OlaHsd (PVG; 180–200g body wt) were used to assess the influence of the benzodiazepine binding-site to the development of tolerance. Rats were divided into six groups: The first receiving saline (0.9%), the second and third diazepam (10.0 mg/kg) daily for 23 days with or without an acute challenge of 2.0 mg/kg diazepam. The fourth group received diazepam (10.…