The present study was designed to examine the role of 5-hydroxytryptamine (5-HT) neurons in the behavioral effects of d-lysergic acid diethylamide (LSD), an indolealkylamine hallucinogen, 2.5-dimethoxy-4-methylamphetamine (DOM) and mescaline, phenethylamine hallucinogens, and phenobarbital, a non-hallucinogen. Male rats, maintained at 70-80% of their free-feeding weights, were trained to press...
It has been reported that the binding of tritiated LSD (at 2 or 4 nm) to frontal cortex is reduced in schizophrenia, a finding that has been interpreted as a reduction in the number of serotonin receptors. The present study, however, reveals in a Scatchard analysis of tritiated LSD binding in frontal cortex in the brains of 13 schizophrenic patients that there was no decrease in binding by...
In blood platelets of rabbits, the shape change-inducing effect of D-lysergic acid diethylamide (D-LSD) has been compared with the D-LSD-binding. D-LSD, but not L-LSD, caused a shape change reaction (EC50 1.3 x 10(-9) M) which was inhibited by various 5-HT antagonists (methergoline and neuroleptic drugs), butaclamol showing marked stereospecificity. Strong inhibitors of 5 HT uptake were only...
Harmine, a hallucinogen with potent monoamine oxidase inhibitory properties, induced abnormal behavior, including tremor, scratching, head twitch and cage biting, in the mouse. A dose-dependent tremor was produced by all routes of administration of harmine. Although oxotremorine tremor was markedly suppressed by atropine, harmine tremor was unaffected by cholinergic drugs, remarkably inhibited...
Circadian fluctuations were measured in the head twitch response produced by 5-methoxy-N1,N1-dimethyltryptamine (5-MeODMT) and p-chloroamphetamine (PCA) in male BK. TO mice. The effects of depleting brain 5-hydroxytryptamine (5-HT) with p-chlorophenylalanine (PCPA) on the 5-MeODMT in the mouse were also studied. Changes in brain 5-HT and 5-hydroxyindoleacetic (5-HIAA) were concomitantly...
Evidence gathered from several experiments where stimulant drugs were given to selected members of adult Stumptail macaque social colonies is presented which suggests that dopamine systems play an important part in the mediation of submissive behavior in this species. Chronic administration of d-amphetamine, 3.2 mg/kg/day, for 12 days, induced a significant increase in submissive gestures...
The purpose of the present study was to determine the role of central catecholaminergic neuronal systems in the effects of LSD, DOM and d-amphetamine on fixed ratio (FR) operant responding in rats. Food-deprived male rats were trained to press a bar for food reinforcement on a FR-40 schedule. Control responding on this schedule is characterized by a rapid, constant rate of responding...
Several 7-substituted derivatives of N,N-dimethyltryptamine (DMT) were prepared and evaluated in the rat fundus serotonin receptor assay and in a behavioral (discriminative stimulus) assay in rats. Both 7-Me- and 5-OMe-7-Me-DMT possess a higher pA2, and 5,7-(OMe)2-DMT a lower pA2, than that of DMT itself. Like DMT, all three of these compounds produce behavioral effects in rats which are...
Seven food deprived male rats were trained to press a bar on a fixed ratio-40 (FR-40) schedule of food reinforcement. Administration of 0.5 mg/kg 2,5-dimethoxy-4-methyl amphetamine (DOM) immediately before the start of the session resulted in cessation of responding for some portion of the 40-min test session. Three successive days of p-chlorophenylalanine (PCPA) administration (100 mg/kg) 30...
Pigeons (N=4) were trained to discriminate between the effects induced by intramuscular (IM) injections of d-LSD and saline using a discrete-trial discrimination paradigm (choice between left and right hand key) in a conventional operant box. The solutions were administered IM 15 min prior to the sessions. A FR 15 schedule was in operation to produce food. Which of the two keys was correct on a...