Phenotypical Screening on Neuronal Plasticity in Hippocampal-Prefrontal Cortex Connectivity Reveals an Antipsychotic with a Novel Profile.

Dysfunction in the hippocampus-prefrontal cortex (H-PFC) circuit is a critical determinant of schizophrenia. Screening of pyridazinone-risperidone hybrids on this circuit revealed EGIS 11150 (S 36549). EGIS 11150 induced theta rhythm in hippocampal slice preparations in the stratum lacunosum molecular area of CA1, which was resistant to atropine and prazosin.

S29434, a Quinone Reductase 2 Inhibitor: Main Biochemical and Cellular Characterization.

Quinone reductase 2 (QR2, E.C. 1.

Persistent therapeutic effect of a novel α5-GABA receptor antagonist in rodent preclinical models of vascular cognitive impairment.

This study examined the potential of the selective extra-synaptic α5-GABA receptor inhibitor S44819 (Egis-13529) to improve cognitive performance in preclinical models of vascular cognitive impairment (VCI). Chronic hypoperfusion of the brain in mice was induced by permanent occlusion of the right common carotid artery (rUCO). rUCO induced impairments of cognitive function in the object recognition test (OR) and the rewarded T-maze (RTM).

Loop F of the GABA receptor alpha subunit governs GABA potency.

Gamma-amino butyric acid (GABA) is an abundant neurotransmitter in the CNS. GABAergic interneurons orchestrate pyramidal neurons in the cerebral cortex, and thus control learning and memory. Ionotropic receptors for GABA (GABAR) are heteropentameric complexes of α, β and γ integral membrane-protein subunits forming Cl -channels operated by GABA, which are vital for brain function and are important drug targets.

Selective inhibition of extra-synaptic α5-GABA receptors by S44819, a new therapeutic agent.

In the mammalian central nervous system (CNS) GABA receptors (GABARs) mediate neuronal inhibition and are important therapeutic targets. GABARs are composed of 5 subunits, drawn from 19 proteins, underpinning expression of 20-30 GABAR subtypes. In the CNS these isoforms are heterogeneously expressed and exhibit distinct physiological and pharmacological properties.

Behavioural pharmacology of the α5-GABA receptor antagonist S44819: Enhancement and remediation of cognitive performance in preclinical models.

Previous work has shown that S44819 is a novel GABAA receptor (GABAR) antagonist, which is selective for extrasynaptic GABARs incorporating the α5 subunit (α5-GABARs). The present study reports on the preclinical neuropsychopharmacological profile of S44819. Significantly, no sedative or pro-convulsive side effects of S44819 were found at doses up to 30 mg/kg i.

Loop-F of the α-subunit determines the pharmacologic profile of novel competitive inhibitors of GABA receptors.

The neurotransmitter γ-amino butyric acid (GABA) has a fundamental role in CNS function and ionotropic (GABA) receptors that mediate many of the actions of GABA are important therapeutic targets. This study reports the mechanism of action of novel GABA antagonists based on a tricyclic oxazolo-2,3-benzodiazepine scaffold. These compounds are orthosteric antagonists of GABA on heteropentameric GABA receptors of αxβ2γ2 configuration expressed in HEK293 cells.

A novel GABA(A) alpha 5 receptor inhibitor with therapeutic potential.

Novel 2,3-benzodiazepine and related isoquinoline derivatives, substituted at position 1 with a 2-benzothiophenyl moiety, were synthesized to produce compounds that potently inhibited the action of GABA on heterologously expressed GABAA receptors containing the alpha 5 subunit (GABAA α5), with no apparent affinity for the benzodiazepine site. Substitutions of the benzothiophene moiety at position 4 led to compounds with drug-like properties that were putative inhibitors of extra-synaptic GABAA α5 receptors and had substantial blood-brain barrier permeability. Initial characterization in vivo showed that 8-methyl-5-[4-(trifluoromethyl)-1-benzothiophen-2-yl]-1,9-dihydro-2H-[1,3]oxazolo[4,5-h][2,3]benzodiazepin-2-one was devoid of sedative, pro-convulsive or motor side-effects, and enhanced the performance of rats in the object recognition test.

Egis-11150: a candidate antipsychotic compound with procognitive efficacy in rodents.

Classical antipsychotics, e.g. haloperidol, chlorpromazine, are potent at controlling the positive symptoms of schizophrenia but frequently elicit extrapyramidal motor side-effects.

Optimization of (arylpiperazinylbutyl)oxindoles exhibiting selective 5-HT₇ receptor antagonist activity.

A series of (arylpiperazinylbutyl)oxindoles as highly potent 5-HT(7) receptor antagonists has been studied for their selectivity toward the 5-HT(1A) receptor and α(1)-adrenoceptor. Several derivatives exhibited high 5-HT(7)/5-HT(1A) selectivity, and the key structural factors for reducing undesired α(1)-adrenergic receptor binding have also been identified. Rapid metabolism, a common problem within this family of compounds, could be circumvented with appropriate substitution patterns on the oxindole carbocycle.

Deramciclane improves object recognition in rats: potential role of NMDA receptors.

The cognition-enhancing properties of deramciclane (N,N-dimethyl-2-([(1R,4R,6S)-1,7,7-trimethyl-6-phenyl-6-bicyclo[2.2.1]heptanyl]oxy)ethanamine) and memantine (3,5-dimethyl-tricyclo[3.

5-HT6/7 receptor antagonists facilitate dopamine release in the cochlea via a GABAergic disinhibitory mechanism.

In humans, serotonin (5-HT) has been implicated in numerous physiological and pathological processes in the peripheral auditory system. Dopamine (DA), another transmitter of the lateral olivocochlear (LOC) efferents making synapses on cochlear nerve dendrites, controls auditory nerve activation and protects the sensory nerve against overactivation. Using in vitro microvolume superfusion techniques we tested 5-HT(6) and 5-HT(7) receptor antagonists whether they can influence dopamine (DA) release from the guinea-pig cochlea in control and in ischemic conditions using currently available and new 5-HT(6) and 5-HT(7) antagonists and mixed antagonists, which were synthesized and characterized for the current study.

Chronic mild stress generates clear depressive but ambiguous anxiety-like behaviour in rats.

A 3-week chronic mild stress (CMS) protocol decreased sucrose preference of rats and increased immobility in the forced swim test. It also induced social avoidance and increased grooming, but acted as if reducing anxiety in the plus-maze. Sucrose preference and social avoidance, but not other measures of the behaviour, showed significant correlation.

Antagonism of AMPA receptors produces anxiolytic-like behavior in rodents: effects of GYKI 52466 and its novel analogues.

Rationale: Although emerging number of data supports the role of glutamate receptors and the potential of their antagonists in anxiety disorders, the involvement of alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA)/kainate receptors in anxiety is less well characterized.

Objective: To evaluate the anxiolytic potential of 2,3-benzodiazepine (2,3BDZ) type AMPA receptor antagonists in various models of anxiety.

Materials And Methods: Whole-cell currents, hippocampal field potentials, elevated plus maze (EPM), meta-chlorophenylpiperazine (mCPP)-induced anxiety model, Vogel test in rats and light-dark test (LD) in mice were used to determine AMPA/kainite receptor properties and anxiolytic-like activity of a series of 2,3BDZ-type compounds.

(Phenylpiperazinyl-butyl)oxindoles as selective 5-HT7 receptor antagonists.

A series of potent 5-hydroxytryptamine 7 (5-HT 7) ligands has been synthesized that contain a 1,3-dihydro-2 H-indol-2-one (oxindole) skeleton. The binding of these compounds to the 5-HT 7 and 5-HT 1A receptors was measured. Despite the structural similarity of these two serotonin receptor subtypes, several derivatives exhibited a high selectivity to the 5-HT 7 receptor.

Effects of 2,3-benzodiazepine AMPA receptor antagonists on dopamine turnover in the striatum of rats with experimental parkinsonism.

Although levodopa is the current "gold standard" for treatment of Parkinson's disease, there has been disputation on whether AMPA receptor antagonists can be used as adjuvant therapy to improve the effects of levodopa. Systemic administration of levodopa, the precursor of dopamine, increases brain dopamine turnover rate and this elevated turnover is believed to be essential for successful treatment of Parkinson's disease. However, long-term treatment of patients with levodopa often leads to development of dyskinesia.

Effect of two noncompetitive AMPA receptor antagonists GYKI 52466 and GYKI 53405 on vigilance, behavior and spike-wave discharges in a genetic rat model of absence epilepsy.

The present study was conducted to investigate the effects of two noncompetitive alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA) receptor antagonists, GYKI 52466 and GYKI 53405 (the racemate of talampanel) on the generation of spike-wave discharges (SWD) parallel with the vigilance and behavioral changes in the genetic absence epilepsy model of WAG/Rij rats. Intraperitoneal (i.p.

Effects of EGIS-7625, a selective and competitive 5-HT2B receptor antagonist.

Our aim was to specify the 5-HT(2) subtype selectivity of EGIS-7625 (1-benzyl-4-[(2-nitro-4-methyl-5-amino)-phenyl]-piperazine), a new 5-HT(2B) ligand, in receptor binding studies and characterize its pharmacology at 5-HT(2A), 5-HT(2B) and 5-HT(2C) receptors in in vivo experiments and in isolated organs, in vitro. EGIS-7625 had high affinity for recombinant human 5-HT(2B) receptors (pK(i) = 9.0) but much weaker affinity for 5-HT(2A) and 5-HT(2C) receptors (pK(i) = 6.

The glycine transporter-1 inhibitors NFPS and Org 24461: a pharmacological study.

The in vitro and in vivo pharmacology of two glycine transporter-1 (GlyT1) inhibitors, N[3-(4'-fluorophenyl)-3-(4'-phenylphenoxy)-propyl]sarcosine (NFPS) and R,S-(+/-)N-methyl-N-[(4-trifluoromethyl)phenoxy]-3-phenyl-propylglycine (Org 24461), was studied. NFPS and Org 24461 inhibited the uptake of [3H]glycine in hippocampal synaptosomal preparation with IC(50) values of 0.022 and 2.

Synthesis and evaluation of 5-HT(2A) and 5-HT(2C) receptor binding affinities of novel pyrimidine derivatives.

In an effort to find potential anxiolytic and/or antipsychotic agents with selective 5-HT(2C) affinity a series of new pyrimidine derivatives was prepared and the binding affinities for 5-HT(2A) and 5-HT(2C) receptors were determined.