RationaleDisruption of auditory event-related evoked potentials (ERPs) P300 and mismatch negativity (MMN), electrophysiological markers of attentive and pre-attentive cognitive processing, is repeatedly described in psychosis and schizophrenia. Similar findings were observed in a glutamatergic model of psychosis, but the role of serotonergic 5-HT2A receptors...
Objective: Schizophrenia patients have a higher prevalence of type 2 diabetes mellitus than the general population, and even first-episode, drug-naive (FEDN) patients with schizophrenia have shown a higher prevalence of impaired glucose tolerance (IGT) than the general population. We aimed to investigate the prevalence of abnormal glucose tolerance after glu...
Serotonergic hallucinogens produce profound changes in perception, mood, and cognition. These drugs include phenylalkylamines such as mescaline and 2,5-dimethoxy-4-methylamphetamine (DOM), and indoleamines such as (+)-lysergic acid diethylamide (LSD) and psilocybin. Despite their differences in chemical structure, the two classes of hallucinogens produce rem...
It has been observed that agents with agonist activity at 5-HT2A receptors prevent neurotoxicity induced by the non-competitive NMDA antagonist, dizocilpine (MK-801). Subsequent behavioral studies reported complete antagonism by LSD and DOM of the stimulus effects of the related NMDA antagonist, phencyclidine [PCP]. The present study sought to extend those o...
Although psilocybin has been trained in the rat as a discriminative stimulus, little is known of the pharmacological receptors essential for stimulus control. In the present investigation rats were trained with psilocybin and tests were then conducted employing a series of other hallucinogens and presumed antagonists. An intermediate degree of antagonism of ...
Introduction: It has been accepted that acute toxicity of psilocin is low and this substance does not create a serious health hazard. Few symptoms observed after intake of Psilocybe mushrooms were mostly limited to the Central Nervous System. Material and methods: In order to readdress the supposed low toxicity and relative safety of natural hallucinogens, w...
The role of 5-HT2A-mediated stimulation of phosphoinositide hydrolysis in the discriminative effects of hallucinogens was investigated in PC12 cells stably expressing the rat 5-HT2A receptor (PC12-5-HT2A cells). The hallucinogenic compounds, D-lysergic acid diethylamide (LSD), (-)2,5-dimethoxy-4-methylamphetamine (DOM), psilocybin, N,N-dimethyltryptamine (DM...
In order to further evaluate the extent to which particular 5-HT receptor subtypes (5-HT1, 5-HT2) might be involved in the behavioral effects of hallucinogenic drugs, rats were trained to discriminate mescaline (10 mg/kg i.p.) from saline and were given substitution (generalization) and combination (antagonism) tests with putatively selective serotonergic an...
Tryptamine produces pharmacologic effects in man and the chronic spinal dog which are similar to those produced by LSD, mescaline, psilocin, DMT, DOM and DOB. These effects include tachycardia, tachypnea, mydriasis, hyperreflexia, behavioral changes and in man, hallucinations. Chronic spinal dogs treated chronically with LSD became tolerant to its ability to...
Previous studies from our laboratory have demonstrated that there are a number of important dissociations between the effects of hallucinogenic drugs on the activity of serotonin-containing dorsal raphe neurons and behavior in freely moving cats. In the present study, we extended this analysis to serotonergic units in the nucleus centralis superior (NCS) and...
The hypothesis that the action of hallucinogenic drugs is mediated by a depression of the activity of brain serotonergic (raphe) neurons was tested by examining the behavioral effects of several hallucinogenic drugs while concurrently monitoring the activity of raphe neurons in freely moving cats. LSD produced a dose-dependent decrease in raphe unit activity...
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-dimet...
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 th...
Evidence has been presented that d-amphetamine interacts with various types of behavior in the context of a conditioning paradigm. Rats exposed simultaneously to a locomotor activity measurement and three dose levels of d-amphetamine on repeated occasions gradually developed dose-related enhancement of drug-stimulated activity, which persisted after disconti...
Room temperature fluorometric and low-temperature phosphorimetric analytical curves of hallucinogens in methanol/water solution have been prepared to demonstrate the absence of interference in common binary mixtures of hallucinogenic drugs. Limits of detection and linear dynamic ranges have been determined for drugs in mixtures. Mixtures containing LSD and a...
