The spontaneous locomotor activity of rats was investigated in an open-field test. Apomorphine and d,1-amphetamine caused a dose dependent increase of locomotor activity. LSD, mescaline, and DMT in low doses were ineffective, when given alone, but caused a strong potentiation of the hypermotility induced by apomorphine and d,1-amphetamine. Cyproheptadine antagonized the potentiating effect of...
The disruption of the temporal distribution of investigatory responses by rats in a novel hole-board following lysergic acid diethylamide-25 (LSD), as described in a companion paper (Geyer and Light, 1979), was found to be a characteristic effect of a variety of hallucinogens. Similar effects were produced by indoleamine hallucinogens, such as LSD, N,N-dimethyltryptamine, and psilocin, and by...
In blood platelets of rabbits isolated by a stractan gradient and incubated in a protein‐poor medium, tryptamine, 5‐hydroxytryptamine (5‐HT) and derivatives, quipazine and mescaline caused a shape change. This shape change was inhibited by low concentrations of methysergide. The most potent antagonists of the 5‐HT‐induced shape change included ergoline derivatives and neuroleptic drugs, which...
Abstract 3,4-Methylenedioxyamphetamine (MDA) is a potent central nervous system (CNS) stimulant chemically and pharmacologically related to amphetamine and mescaline [1–3] (Fig. 1). The phenylisopropylamine portion of the molecule gives MDA marked sympathomimetic activity similar to amphetamine demonstrated by peripheral vasoconstriction, tachycardia, pupillary dilation, and effects on other...
The effects of several indoleamines and phenethylamines were studied in the chronic spinal dog and compared with two standard drugs, LSD and amphetamine. In the nontolerant chronic spinal dog, their effects on a variety of physiologic and behavioral functions were measured in untreated dogs, as well as dogs treated with certain antagonists. The effects of the antagonists phenoxybenzamine and...
A series of ring-substituted hallucinogenic amphetamines has been analyzed using molecular connectivity. A correlating equation has been found between potency and connectivity terms. The equation permits an interpretation of SAR. The equation is capable of predicting potency for amphetamines not in the list and mescalines and tryptamines.
The dopaminergic actions of various hallucinogenic drugs were assessed by examining their effects on turning behavior in rats with unilateral 6-hydroxydopamine lesions of the nigro-striatal pathway. LSD (0.1 and 0.2 mg/kg) produced strong contralateral turning, indicating that it is a potent dopamine receptor agonist, while BOL (5 mg/kg), a non-hallucinogenic congener of LSD, was found to be a...
Over the years there have been many reviews of the phenomenology of hallucinogens and schizophrenia. The vast majority of these have been written by scientists who interviewed research subjects and subsequently extracted and summarized the experiences of these subjects. Comparisons of schizophrenia with drug-induced experiences have proven useful in directing further research aimed at...
Investigations were carried out on the interactions of the hallucinogenic drug, D-lysergic acid diethylamide (D-LSD), and other serotonin antagonists with catecholamine-sensitive adenylate cyclase systems in cell-free preparations from different regions of rat brain. In equimolar concentration, D-LSD, 2-brono-D-lysergic acid diethylamide (BOL), or methysergide (UML) strongly blocked maximal...
Normal mental functions can be disrupted by many kinds of drugs. Hallucinogens are of special interest because of their ability to impair higher centers without producing substantial effect on other functions of the central nervous system. While the mechanism of action of hallucinogens has not been clarified, the striking structural resemblance between certain of these agents and several...