Drugs purported to have selective affinities for 5-HT1A, 5-HT1B, and 5-HT2 receptors were tested in rats trained with 0.1 mg LSD versus saline. Included were 5-methoxy-dimethyltryptamine (MDMT), 2,5-dimethoxy-4-methyl-amphetamine (DOM), 8-hydroxy-2-(di-n-propylamino) tetralin (8-OH-DPAT), m-trifluoromethylphenyl-piperazine (TFMPP), and 5-methoxy-3-(1,2,3,6-tetrahydro-4-pyridinyl)-1H-indole...
Twenty-one indolealkylamines, some of which are known to be psychoactive in man, were examined for their binding interactions with rat brain cortical 5-HT2 receptors labeled with the antagonist radioligand [3H]ketanserin in order to develop structure-activity relationships for binding at these sites. Features investigated included aromatic, alpha-methyl and terminal amine substituents....
Various direct- and indirect-acting serotonin (5-HT) agonists serve as training drugs in tests of stimulus control of behavior; such agents include: 5-hydroxytryptophan, 5-methoxy-N,N-dimethyltryptamine, and fenfluramine. However, with the recent discovery of multiple populations of central 5-HT binding sites, the concept of site-selective serotonergic agents needs to be addressed. Certain...
Phencyclidine (PCP)-induced behaviors were compared with 5-methoxy-N,N-dimethyltryptamine (5-MeODMT)- and p-chloroamphetamine-induced behaviors in rats pretreated with ritanserin or 5,7-dihydroxytryptamine (5,7-DHT) in order to investigate whether PCP interacts with 5-hydroxytryptamine2 (5-HT2) receptors. Head-twitch and wet-dog shake induced by p-chloroamphetamine, a 5-HT releaser, and...
A group of ten rats was trained to obtain food pellets in an 8-arm radial maze. The effects of pretreatment with (+)-Lysergic acid diethylamide (+)-tartrate (LSD), m-trifluoromethylphenylpiperazine (TFMPP), 5-methoxy-N,N-dimethyltryptamine oxalate (5-MeO-DMT), racemic 8-hydroxy-2-(di-n-propylamino)tetralin HBr (8-OH-DPAT), and 5-methoxy-3-(1,2,3,6-tetrahydro-4-pyridinyl)-1H-indole succinate (RU...
Ritanserin (0.125, 0.25, 0.5, 1.0 and 2.0 mg/kg s.c.), a selective serotonin (5-HT2) receptor antagonist, produced a dose-dependent inhibition of the head-twitch response induced in mice by phencyclidine (PCP) and 5-methoxy-N,N-dimethyltryptamine (5-MeODMT). In contrast, ritanserin, dose dependently increased PCP- and 5-MeODMT-induced head-weaving. There was a significant inverse relationship...
This study was designed to assess whether phencyclidine (PCP)-induced head-twitch was antagonized by ritanserin, a selective serotonin (5-HT2) receptor antagonist, in mice and rats to confirm the involvement of 5-hydroxytryptamine (5-HT) neurons in PCP actions in comparison with 5-methoxy-N,N-dimethyltryptamine (5-MeODMT)-induced behavior. PCP (7.5, 10 and 12.5 mg/kg, i.p.)-induced head-twitch...
The use of a series of liquid chromatographic techniques involving cation-exchange, reverse-phase and normal-phase chromatography has permitted the separation and characterisation of a number of metabolites of the psychotomimetic indolealkylamines N,N-dimethyltryptamine and 5-methoxy-N,N-dimethyltryptamine which were isolated following incubation of these compounds with rat tissue extracts. In...
In rats treated with phencyclidine (PCP) repeatedly (PCP 10 mg/kg per day for 14 days), the back-pedalling, head-weaving and turning induced by PCP were attenuated (tolerance), while PCP-induced sniffing, rearing and ambulation were potentiated (supersensitivity). The behavior induced by the direct and indirect serotonin (5-HT) agonists, 5-methoxy-N,N-dimethyltryptamine and p-chloroamphetamine,...
This study was designed to assess whether phencyclidine (PCP)-induced behaviors in rats were potentiated after two days' withdrawal from chronic methysergide (a 5-HT2 receptor blocker) treatment (10 mg/kg per day i.p. for 12 days), in order to confirm the involvement of 5-hydroxytryptamine (5-HT) neurons in PCP actions. The PCP (10 mg/kg)-induced behaviors (head-twitch, head-weaving, turning...