Serotonin (5-hydroxytryptamine, 5-HT) is an important neurotransmitter that is found in both the central and peripheral nervous systems. 5-HT mediates its diverse physiological responses through 7 different 5-HT receptor families: 5-HT(1), 5-HT(2), 5-HT(3), 5-HT(4), 5-HT(5), 5-HT(6), and 5-HT(7) receptors. Among them, the 5-HT(6) receptor (5-HT(6)R) is the most recently cloned serotonin recepto...

The synthesis of 3-amino-1-nitroguanidine (3-ANQ) and 5-hydrazino tetrazole (5-HT) derivatives as new energetic materials are described. Reaction of 3-ANQ with triethyl orthoformate leads to the formation of 3-nitramino triazole while no reaction was observed whit 5-HT. Addition of NaN3 to a mixture of 3-ANQ and triethyl orthoformate, afforded 1-nitroguanidyl tetrazole in excelle...

Background and objectives: Natural products are one of the major sources for investigations of novel medicines. Zataria multiflora Boiss (ZM) has shown pharmacological activities especially in gastrointestinal tract; however, there are limited studies about its cytotoxicity effects. In this study, the effect of Zataria multiflora was examined on two colon canc...

Serotoninergic neurons in the central nervous system impinge on many other neurons and modulate their neurotransmitter release. This review focuses on 1) the function of presynaptic 5-hydroxytryptamine (5-HT) heteroreceptors on axon terminals of central cholinergic, dopaminergic, noradrenergic, or GABAergic neurons and 2) the role of GABAergic interneurons expressing 5-HT heteroreceptors in the...

The dorsal (DR) and median raphe (MR) nuclei contain 5-hydroxytryptamine (serotonin, 5-HT) cell bodies that give rise to the majority of the ascending 5-HT projections to the forebrain limbic areas that control emotional behavior. In the past, the electrophysiological identification of neurochemically identified 5-HT neurons has been limited. Recent technical developments have made it possible ...

5-Hydroxytryptamine (5-HT; serotonin) plays an important role in the descending control of nociception. 5-HT and its receptors have been extensively studied in the modulation of nociceptive transmission at the spinal level using behavioral tests that may be affected by the effects of 5-HT on motor performance and skin temperature. Using electrophysiological methods, the present study aimed to s...

We investigated whether selective inhibition of serotonin (5-hydroxytryptamine; 5-HT) transporter with citalopram leads to accumulation of 5-HT in catecholaminergic neurons. In the rabbit olfactory tubercle, citalopram (1-10 microM) inhibited [(3)H]5-HT uptake; however, the maximal degree of inhibition achieved was 70%. Addition of nomifensine (1-10 microM) was required for complete inhibition ...

In previous studies, we have found that 5-hydroxytryptamine (5-HT) is a potent stimulant of duodenal mucosal bicarbonate secretion (DMBS) in mice. The aim of the present study was to determine the intracellular signaling pathways and 5-HT receptor subtypes involved in 5-HT-induced DMBS. Bicarbonate secretion by murine duodenal mucosa was examined in vitro in Ussing chambers. 5-HT receptor invol...

Serotonin [5-hydroxytryptamine (5-HT)]-absorbing neurons use serotonin reuptake transporter (SERT) to uptake 5-HT from extracellular space but do not synthesize it. While 5-HT-absorbing neurons have been identified in diverse organisms from Caenorhabditis elegans to humans, their function has not been elucidated. Here, we show that SERT in 5-HT-absorbing neurons controls behavioral response to ...

Serotonin (5-hydroxytryptamine; 5-HT) is released during platelet aggregation, a phenomenon commonly observed in blood clot formation and venous diseases. Once released, 5-HT can interact with its receptors in the peripheral vasculature to modify vascular tone. The goal of this study was to perform a detailed pharmacological characterization of the 5-HT receptors involved in the contractile res...