Search results for " serotonin"
showing 10 items of 140 documents
Characterisation of serotonin transport mechanisms in rainbow trout peripheral blood lymphocytes: role in PHA-induced lymphoproliferation
1999
Abstract AbstractIn this study we investigated the serotonin transport mechanisms in rainbow trout (Oncorhynchus mykiss) peripheral blood lymphocytes We have observed that the transport of serotonin is a membrane transport process that have the properties of a secondary active transport system The binding isotherm of [3H]-paroxetine a serotonin transport blocker demonstrated a high-affinity binding site with a positive type of cooperativity Hill coefficient being higher than unity Known specific inhibitors of the mammalian serotonin transporter significantly inhibited the uptake process in fish lymphocytes In order to demonstrate the physiological relevance of the serotonin transporter in T…
Enhancement of the FGFR1 signaling in the FGFR1-5-HT1A heteroreceptor complex in midbrain raphe 5-HT neuron systems. Relevance for neuroplasticity an…
2015
New findings show existence of FGFR1-5-HT1A heteroreceptor complexes in 5-HT nerve cells of the dorsal and median raphe nuclei of the rat midbrain and hippocampus. Synergistic receptor-receptor interactions in these receptor complexes indicated their enhancing role in hippocampal plasticity. The existence of FGFR1-5-HT1A heteroreceptor complexes also in midbrain raphe 5-HT nerve cells open up the possibility that antidepressant drugs by increasing extracellular 5-HT levels can cause an activation of the FGF-2/FGFR1 mechanism in these nerve cells as well. Therefore, the agonist modulation of the FGFR1-5-HT1A heteroreceptor complexes and their specific role is now determined in rat medullary …
Fibroblast Growth Factor Receptor 1– 5-Hydroxytryptamine 1A Heteroreceptor Complexes and Their Enhancement of Hippocampal Plasticity
2011
Background The hippocampus and its 5-hydroxytryptamine transmission plays an important role in depression related to its involvement in limbic circuit plasticity. Methods The analysis was made with bioluminescence resonance energy transfer, co-immunoprecipitation, in situ proximity ligation assay, binding assay, in cell western and the forced swim test. Results Using bioluminescence resonance energy transfer analysis, fibroblast growth factor receptor 1 (FGFR1)-5-hydroxytryptamine 1A (5-HT1A) receptor complexes have been demonstrated and their specificity and agonist modulation characterized. Their presence based on co-immunoprecipitation and proximity ligation assay has also been indicated…
GRANULOMATOUS MASTITIS DURING CHRONIC ANTIDEPRESSANT THERAPY: IS IT POSSIBLE A CONSERVATIVE THERAPEUTIC APPROACH?
2012
Granulomatous mastitis is a rare benign inflammatory disease of the breast with multiple etiologies such as tuberculosis, sarcoidosis, foreign body reaction, and mycotic and parasitic infections. In contrast, idiopathic granulomatous mastitis (IGM) is characterized by the presence of chronic granulomatous lobulitis in the absence of an obvious etiology. Clinically and radiologically it may mimic breast carcinoma and so awareness of surgeons, pathologists, and radiologists is essential to avoid unnecessary mastectomies. Cases of IGM are reported during antidepressant therapy in patients also showing high levels of prolactinemia. In these cases, we believe that surgical excision must be avoid…
Pharmacokinetics of selective serotonin reuptake inhibitors
2000
The five selective serotonin reuptake inhibitors (SSRIs), fluoxetine, fluvoxamine, paroxetine, sertraline, and citalopram, have similar antidepressant efficacy and a similar side effect profile. They differ, however, in their pharmacokinetic properties. Under steady-state concentrations, their half-lives range between 1 and 4 days for fluoxetine (7 and 15 days for norfluoxetine) and between 21 (paroxetine) and 36 (citalopram) hr for the other SSRIs. Sertraline and citalopram show linear and fluoxetine, fluvoxamine, and paroxetine nonlinear pharmacokinetics. SSRIs underlie an extensive metabolism with high interindividual variability, whereby cytochrome P450 (CYP) isoenzymes play a major rol…
Axonal control of the adult neural stem cell niche.
2014
SummaryThe ventricular-subventricular zone (V-SVZ) is an extensive germinal niche containing neural stem cells (NSCs) in the walls of the lateral ventricles of the adult brain. How the adult brain’s neural activity influences the behavior of adult NSCs remains largely unknown. We show that serotonergic (5HT) axons originating from a small group of neurons in the raphe form an extensive plexus on most of the ventricular walls. Electron microscopy revealed intimate contacts between 5HT axons and NSCs (B1) or ependymal cells (E1) and these cells were labeled by a transsynaptic viral tracer injected into the raphe. B1 cells express the 5HT receptors 2C and 5A. Electrophysiology showed that acti…
Serotonin Involvement in the Basal Ganglia Pathophysiology: Could the 5-HT2C Receptor be a New Target for Therapeutic Strategies?.
2006
The basal ganglia are a highly interconnected group of subcortical nuclei in the vertebrate brain that play a critical role not only in the control of movements but also in some cognitive and behavioral functions. Several recent studies have emphasized that serotonergic pathways in the central nervous system (CNS) are intimately involved in the modulation of the basal ganglia and in the pathophysiology of human involuntary movement disorders. These observations are supported by anatomical evidence demonstrating large serotonergic innervation of the basal ganglia. In fact, serotonergic terminals have been reported to make synaptic contacts with dopamine (DA)-containing neurons and gamma-amin…
Serotoninergic Modulation of Phototactic Variability Underpins a Bet-Hedging Strategy in Drosophila melanogaster
2021
When organisms’ environmental conditions vary unpredictably in time, it can be advantageous for individuals to hedge their phenotypic bets. It has been shown that a bet-hedging strategy possibly underlies the high inter-individual diversity of phototactic choice in Drosophila melanogaster. This study shows that fruit flies from a population living in a boreal and relatively unpredictable climate have more variable variable phototactic biases than fruit flies from a more stable tropical climate, consistent with bet-hedging theory. We experimentally show that phototactic variability of D. melanogaster is regulated by the neurotransmitter serotonin (5-HT), which acts as a suppressor of the var…
Influence of concomitant medications on the total clearance and the risk for supra-therapeutic plasma concentrations of Citalopram. A population-base…
2014
Introduction: The main objective of this study was to investigate the influence of the use of multiple medications and other risk factors on citalopram plasma concentrations. Methods: A retrospective cohort study with a naturalistic population of 957 patients for whom routine therapeutic drug monitoring (TDM) of citalopram had been requested between 2006 and 2013 was conducted. Results: Concomitant drugs inhibiting at least 2 different CYP subtypes involved in the metabolism of citalopram decreased statistically significantly the total clearance (Clt). Compared to younger patients over 64-year-old patients had on average a 4.5 times higher risk rate of supra-therapeutic plasma concentration…
Positron emission tomography in CNS drug discovery and drug monitoring.
2014
Molecular imaging methods such as positron emission tomography (PET) are increasingly involved in the development of new drugs. Using radioactive tracers as imaging probes, PET allows the determination of the pharmacokinetic and pharmacodynamic properties of a drug candidate, via recording target engagement, the pattern of distribution, and metabolism. Because of the noninvasive nature and quantitative end point obtainable by molecular imaging, it seems inherently suited for the examination of a pharmaceutical’s behavior in the brain. Molecular imaging, most especially PET, can therefore be a valuable tool in CNS drug research. In this Perspective, we present the basic principles of PET, th…