5ht6

5HT6 receptor antagonists offer the potential for safe and effective drugs against obesity, because they can reduce weight without causing serious side effects in the cardiovascular system. Also, their anorexic effect is associated with reduced food intake via an enhancement of satiety. In the present study we investigated the anorexic effect of idalopirdine (LuAE58054) in a model of obesity induced by high-fat diet. To induce obesity in rats, the animals were treated with feed with a fat content of 40 %. Body weight was controlled and the amount of food and water consumed was determined...

UNLABELLED: Antagonism of 5-hydroxytrypamine-6 (5HT6) receptors is associated with procognitive effects in preclinical species, suggesting a therapeutic potential for this mechanism in Alzheimer disease (AD) and other cognitive diseases. In a phase 2 dose study, SB742457, a novel 5HT6 antagonist, showed increasing procognitive effects in patients with AD as the dose increased, with a procognitive signal in AD patients at a dose of 35 mg/d superior to the other doses tested (5 and 15 mg/d)...

Antipsychotic drugs are widely used in the treatment of schizophrenia and psychotic disorder. The lack of antipsychotic response and treatment-induced side-effects, such as neuroleptic syndrome, polydipsia, metabolic syndrome, weight gain, extrapyramidal symptoms, tardive dyskinesia or prolactin increase, are the two main reasons for non-compliance and increased morbidity in schizophrenic patients. During the past decades intensive research has been done in order to determine the influence of genetic variations on antipsychotics dosage, treatment efficacy and safety...

Preclinical studies indicate both activation and blockade of serotonin6 (5-HT6) receptors may produce antidepressant-like effects. Depression is a common symptom in Parkinson's disease (PD); however, its pathophysiology is unclear. Here we examined whether 5-HT6 receptors in the dorsal hippocampus (DH) involve in the regulation of PD-associated depression. Unilateral 6-hydroxydopamine lesions of the medial forebrain bundle in rats induced depressive-like responses as measured by the sucrose preference and forced swim tests when compared to sham-operated rats...

BACKGROUND: It is a well-known fact that 5HT6 ligands increase glutamate levels. In the current study we investigated whether a 5HT6 antagonist, SB399885 would show antidepressant like property at a dose which would significantly increase the glutamate levels. Further we studied if the combination of a 5HT6 antagonist and N-methyl-D-aspartate (NMDA) antagonist, memantine would restore the antidepressant property. As dementia and depression are co-morbid, we evaluated if this combination would have an effect on cognition...

The formation of ligand-protein complexes requires simultaneous adaptation of the binding partners. In structure based virtual screening, high throughput docking approaches typically consider the ligand flexibility, but the conformational freedom of the protein is usually taken into account in a limited way. The goal of this study is to elaborate a methodology for incorporating protein flexibility to improve the virtual screening enrichments on GPCRs. Explicit-solvated molecular dynamics simulations (MD) were carried out in lipid bilayers to generate an ensemble of protein conformations for the X-ray structures and homology models of both aminergic and peptidergic GPCRs including the chemokine CXCR4, dopamine D3, histamine H4, and serotonin 5HT6 holo receptor complexes...

UNLABELLED: The serotoninergic system as a target for add-on treatment seems to be a promising approach in patients with schizophrenia. OBJECTIVE: To clarify if selective 5HT-6 antagonist AVN-211 (CD-008-0173) adds clinical and cognitive effects to stable antipsychotic treatment. METHODS: A randomized, double-blind, placebo-controlled, add-on, 4r-week trial in 47 schizophrenia patients (21 patients receiving study drug and 26 receiving placebo) who were stabilized on antipsychotic medication was performed...

DEVELOPMENT: Asenapine, recently marketed in United States and ready to be so in Europe, is a multimodal action second-generation antipsychotic, with high affinity for multiple dopaminergic (D2, D3 y D4), serotonergic (5HT2A, 5HT2B, 5HT2C, 5HT6 and 5HT7) and adrenergic (α1A, α2A, α2B and α2C) receptors. Asenapine has to be administered sublingually. After going through succesfully the preliminary phases of development, several clinical trials have been completed in two main indications: schizophrenia and mania...

The formation of primary cilia is a highly choreographed process that can be disrupted in developing neurons by overexpressing neuromodulatory G-protein-coupled receptors GPCRs or by blocking intraflagellar transport. Here, we examined the effects of overexpressing the ciliary GPCRs, 5HT6 and SSTR3, on cilia structure and the differentiation of neocortical neurons. Neuronal overexpression of 5HT6 and SSTR3 was achieved by electroporating mouse embryo cortex in utero with vectors encoding these receptors. We found that overexpression of ciliary GPCRs in cortical neurons, especially 5HT6, induced the formation of long (>30 μm) and often forked cilia...

Despite risperidone's proven safety and efficacy, existing pharmacogenetic knowledge could be applied to improve its clinical use. The present work aims to summarize the information about genetic polymorphisms affecting risperidone adverse reactions and efficacy during routine clinical practice. The most relevant genes involved in the metabolism of the drug (i.e., CYP2D6, CYP3A and ABCB1) appear to have the greatest potential to predict differences in plasma concentrations of the drug and its interactions, but also relate to side effects, such as neuroleptic syndrome, weight gain or polydipsia...

Alterations in synaptic plasticity and neurocognitive function with age have been well documented in the literature. These changes are accompanied by modifications of neurotransmitter systems in the central nervous system (CNS). The serotonergic system in particular plays an important role in attention, alertness and cognition. Disturbances in serotonergic function have been implicated in differing neurological and neuropsychiatric disorders including depression, psychosis aggression and dementia. The serotonin receptor subtype 5HT6 is distributed within CNS regions relevant to learning and memory, including the striatum, cortex and hippocampus...

Serotonin is involved in several central nervous system functions including pain threshold, mood regulation and drug reward. Overuse of acute medications is commonly identified as a causative factor for medication overuse headache (MOH). Apparently, MOH shares with other kinds of drug addiction some common neurobiological pathways. The objective of this study is to assess the role of serotonin metabolism genes in the genetic liability to MOH. We performed a genetic association study using polymorphisms of five serotonin metabolism-related genes: serotonin transporter (5HTT), serotonin receptor 1A(5-HT1A), serotonin receptor 1B (5-HT1B), serotonin receptor 2A (5-HT2A) and serotonin receptor 6 (5HT6)genes...

BACKGROUND: The World Health Organization (WHO) report has predicted that major depression will become a key cause of illness-induced disability by the year 2020, second only to ischemic heart diseases. OBJECTIVES/METHODS: Although a large number of antidepressant drugs (from monoamine oxidase inhibitors and tricyclic antidepressants to dual reuptake inhibitors) are available for treatment of the disease, approximately 30% of patients failed to respond to this therapy...

STUDY OBJECTIVES: Serotonin (5-HT) has long been implicated in the control of sleep and wakefulness. This study evaluated the hypnotic efficacy of the 5-HT6 antagonist RO4368554 (RO) and the 5-HT2A receptor antagonist MDL100907 (MDL) relative to zolpidem. DESIGN: A randomized, repeated-measures design was utilized in which Wistar rats received intraperitoneal injections of RO (1.0, 3.0, and 10 mg/kg), MDL (0.1, 1.0 and 3.0 mg/kg), zolpidem (10 mg/kg), or vehicle in the middle of the dark (active) period...

This review summarizes data on currently used antiobesity drugs and new compounds under clinical development. Three antiobesity drugs are currently accepted for long-term use. Sibutramine is a noradrenaline and serotonin reuptake inhibitor which reduces body weight by about 4-5 kg but increases heart rate and arterial blood pressure. Orlistat is a gastrointestinal lipase inhibitor which results in mean weight loss by about 3 kg and reduces the incidence of type 2 diabetes in patients with impaired glucose tolerance; however, adverse gastrointestinal effects have been observed...

PURPOSE: To determine the relative density and tissue localization of mRNAs for serotonin (5-hydroxytryptamine; 5HT) receptor subtypes in human ocular tissues and correlate with their possible functions in the eye. METHODS: Total RNA was extracted from human ocular tissues samples from multiple donors and transcribed into cDNA. An optimized reverse transcriptase polymerase chain reaction (RT-PCR) procedure was then used to amplify the signals using primers designed against human 5HT receptor cDNAs...

Ecstasy, (+/-)-3,4-methylenedioxy-metamphetamine (MDMA), is a popular recreational drug among young people. The present study aims to mimic MDMA intake among adolescents at dance clubs, taking repeated doses in the same evening on an intermittent basis. Male Sprague-Dawley rats received either 3x1 or 3x5 mg/kg/day (3 h apart) every seventh day during 4 weeks. We used real-time RT-PCR to determine the gene expression of serotonin 5HT1A, 5HT1B, 5HT2A, 5HT2C, 5HT3, 5HT6 receptors and dopamine D1, D2, D3 receptors in seven brain nuclei...

A "partial" rodent model for schizophrenia has been used to characterize the regulation of hippocampal genes in response to amygdalar activation. At 96 h after the administration of picrotoxin into the basolateral nucleus, we have observed an increase in the expression of genes associated with 18 different monoamine (ie adrenergic alpha 1, alpha 2 and beta 2, serotonergic 5HT5b and 5HT6, dopamine D4 and muscarinic m1, m2 and m3) and peptide (CCK A and B, angiotensin 1A, mu and kappa opiate, FSH, TSH, LH, GNRH, and neuropeptide Y) G-protein coupled receptors (GPCRs)...

Previous genetic-response studies, usually without considering environmental factors, encountered great difficulties in replication of results. Although atypical antipsychotics are becoming the mainstay for schizophrenia treatment which makes an antipsychotic "atypical" remains unclear. Risperidone (a widely used atypical antipsychotic agent) and several other atypicals have high affinities for 5-HT6 and 5-HT7 receptors. This study investigated the effects of the T-->C 267 polymorphism in the 5HT6 receptor gene and two rare Pro279Leu and Thr92Lys substitutions in the 5HT7 receptor gene on risperidone efficacy after rigorous control for nongenetic confounders...

The antipsychotic drug clozapine, acts via interaction with selective neurotransmitter receptor systems. Its use however, is associated with life-threatening agranulocytosis. The mechanism by which this occurs and its possible relationship with the drug's atypicality remain unclear. As a first step in identifying mechanistic pathways involved, profiling of neurotransmitter receptors on human neutrophils, mononuclear and bone marrow stromal cells as putative targets for clozapine-mediated toxicity was undertaken...