Transcripts encoding 5-HT(2C) receptors are modified posttranscriptionally by RNA editing, generating up to 24 protein isoforms. In recombinant cells, the fully edited isoform, 5-HT(2C-VGV), exhibits blunted G-protein coupling and reduced constitutive activity. The present studies examine the signal transduction properties of 5-HT(2C-VGV) receptors in brain to determine the in vivo consequences...

The regulation of extracellular levels of 5-hydroxytryptamine (serotonin) (5-HT) in the striatum and ventral hippocampus was studied using in vivo microdialysis in awake, unrestrained wild-type 5-HT(1A) and 5-HT(1B) receptor knockout mice. Systemic administration of the selective serotonin reuptake inhibitor fluoxetine evoked a significant dose-dependent increase in extracellular 5-HT in both t...

A series of N-benzylated-5-methoxytryptamine analogues was prepared and investigated, with special emphasis on substituents in the meta position of the benzyl group. A parallel series of several N-benzylated analogues of 2,5-dimethoxy-4-iodophenethylamine (2C-I) also was included for comparison of the two major templates (i.e., tryptamine and phenethylamine). A broad affinity screen at serotoni...

To assess the pharmacodynamic profile of ALEPH-2, a phenylisopropylamine derivative with alleged anxiolytic and hallucinogenic properties, Xenopus laevis oocytes were microinjected with either of the rat cRNA for the 5-HT2A or the 5-HT2C receptor. Concentration-response curves were obtained following the exposure of the oocytes to varying concentrations of either ALEPH-2 or 5-hydroxytryptamine ...

This study aimed to demonstrate the influence of the systemic administration of l-5-hydroxy-tryptophan (L-HTP) on the plasma levels of melatonin during the dark period in quails. Throughout daylight, the plasma levels of melatonin did not differ significantly, oscillating between 110.2 +/- 15.8 pg.mL(-1) and 157.4 +/- 34.8 pg.mL(-1), from 8 to 16 hours. L-HTP (25 mg.kg(-1), through the intracel...

ABSTRACT Morphological remodeling of dendritic spines is critically involved in memory formation and depends on adhesion molecules. Serotonin receptors are also implicated this remodeling, though the underlying mechanisms remain enigmatic. Here, we uncovered a signaling pathway involving molecule L1CAM (L1) serotonin receptor 5-HT4 (5-HT4R, encoded by HTR4). Using Förster resonance energy trans...

To determine whether measurement of serotonin in urine would give useful complementary information to the usual measurement of 5-hydroxyindoleacetic acid (5-HIAA) in urine and platelet serotonin in platelets, I measured these analytes in 75 consecutive patients with carcinoid tumors, and found that 75% had above-normal urinary 5-HIAA excretion, 64% had above-normal serotonin excretion, and 64% ...

The serotonin type IA (5-HT1A) receptors are members of a superfamily of seven transmembrane domain receptors that couple to GTP binding regulatory proteins (G-proteins). Serotonergic signalling has been shown to play an important role in alcohol tolerance and dependence. We have studied the effects of alcohols on ligand (agonist and antagonist) binding to bovine hippocampal 5-HT1A receptor in ...

A variety of clinical observations suggest that certain forms of epilepsy are due to long-term, progressive changes in neural networks that eventually provoke spontaneous and recurring seizures. Recently, there has been growing evidence that serotonergic neurotransmission modulates experimentally induced seizures and is involved in the enhanced seizure susceptibility observed in some geneticall...