There is currently a resurgence in exploring the utility of classical psychedelics to treat depression, addiction, anxiety disorders, cluster headaches, and many other neuropsychiatric disorders. A biological target of these compounds, and a hypothesized target for their therapeutic actions, is the 5-HT2A serotonin receptor. Here, we present 7 cryo-EM structures covering all major compound...
At first glance, it appears there is little difference between the molecular structures of methylenedioxymethamphetamine (MDMA), which has an N -methyl attached to its amino group, and methylenedioxyamphetamine (MDA), a primary amine that is recognized to have hallucinogenic activity. It is known from studies with other hallucinogenic amphetamines that N -methylation of hallucinogenic...
Abstract Initial interest in the value of psychedelic drugs (“psychotomimetics”) in psychiatry began in the early 20th century, with explorations of the possibility that mescaline or peyote could produce psychosis-like effects. Over time, interest was focused on whether the effects of psychedelics could inform as to the underlying basis for psychiatric disorders. As research continued, and...
A strategy to replace the ethylamine side chain of 2,5-dimethoxy-4-iodoamphetamine (DOI, 1a), and 2,5-dimethoxy-4-bromoamphetamine (DOB, 1b) with a cyclopropylamine moiety was successful in leading to compounds with high affinity at the 5-HT2 family of receptors; and the more potent stereoisomer of the cyclopropane analogues had the expected (−)-(1R,2S)-configuration. Screening for affinity at...
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...
Psilocybin (4-phosphoryloxy-N,N-dimethyltryptamine) is an indole-based secondary metabolite produced by numerous species of mushrooms. South American Aztec Indians referred to them as teonanacatl, meaning "god's flesh," and they were used in religious and healing rituals. Spanish missionaries in the 1500s attempted to destroy all records and evidence of the use of these mushrooms. Nevertheless,...
Lysergic acid diethylamide (LSD), the prototypical “psychedelic,” may be unique among psychoactive substances. In the decades that followed its discovery, the magnitude of its effect on science, the arts, and society was unprecedented. LSD produces profound, sometimes life-changing experiences in microgram doses, making it a particularly powerful scientific tool. Here we sought to examine its...
Psychedelics (serotonergic hallucinogens) are powerful psychoactive substances that alter perception and mood and affect numerous cognitive processes. They are generally considered physiologically safe and do not lead to dependence or addiction. Their origin predates written history, and they were employed by early cultures in many sociocultural and ritual contexts. After the virtually...
Background: In the past few years, the issue of ‘microdosing’ psychedelics has been openly discussed in the public arena where claims have been made about their positive effect on mood state and cognitive processes such as concentration. However, there are very few scientific studies that have specifically addressed this issue, and there is no agreed scientific consensus on what microdosing is....
Rationale The lysergamide lysergic acid diethylamide (LSD) is a prototypical classical hallucinogen with remarkably high potency. LSD remains a popular recreational drug but is also becoming an important research tool for medical and neuroscience studies. Recently, several lysergamides that are close structural analogs of LSD have been sold as recreational drugs, which suggests that further...
Hallucinogenic drugs potently alter human behavior and have a millennia-long history of use for medicinal and religious purposes. Interest is rapidly growing in their potential as CNS modulators and therapeutic agents for brain conditions. Antimuscarinic cholinergic drugs, such as atropine and scopolamine, induce characteristic hyperactivity and dream-like hallucinations and form a separate...
Lysergic acid diethylamide (LSD) is one of the most potent psychoactive agents known, producing dramatic alterations of consciousness after submilligram (≥20 μg) oral doses. Following the accidental discovery of its potent psychoactive effects in 1943, it was supplied by Sandoz Laboratories as an experimental drug that might be useful as an adjunct for psychotherapy, or to give psychiatrists...
Psychedelic drugs, such as lysergic acid diethylamide (LSD), mescaline, and psilocybin, exert profound effects on brain and behavior. After decades of difficulties in studying these compounds, psychedelics are again being tested as potential treatments for intractable biomedical disorders. Preclinical research of psychedelics complements human neuroimaging studies and pilot clinical trials,...
Lysergic acid diethylamide (LSD) is perhaps one of the best‐known psychoactive substances and many structural modifications of this prototypical lysergamide have been investigated. Several lysergamides were recently encountered as ‘research chemicals’ or new psychoactive substances (NPS). Although lysergic acid morpholide (LSM‐775) appeared on the NPS market in 2013, there is disagreement in...
This essay describes the founding of the Heffter Research Institute in 1993 and its development up to the present. The Institute is the only scientific research organization dedicated to scientific research into the medical value of psychedelics, and it has particularly focused on the use of psilocybin. The first clinical treatment study was of the value of psilocybin in obsessive-compulsive...
A strategy to replace the ethylamine side chain of 2,5-dimethoxy-4-iodoamphetamine (DOI, 1a), and 2,5-dimethoxy-4-bromoamphetamine (DOB, 1b) with a cyclopropylamine moiety was successful in leading to compounds with high affinity at the 5-HT(2) family of receptors; and the more potent stereoisomer of the cyclopropane analogues had the expected (-)-(1R,2S)-configuration. Screening for affinity...
The objective of this work is to characterize genetic and proteomic changes in a novel rat model of schizophrenia. Three‐month treatment with low doses of the hallucinogenic drug, LSD, induces a range of abnormal behaviors including social deficits, hyperactivity, and anhedonia. These behavioral changes persist in the absence of drug , and likely result from neuroadaptive changes in the medial...
Abstract Of the 14 known types of serotonin receptors one of the most extensively studied is the 5‐HT 2A (5‐hydroxytryptamine) receptor. In the brain, this receptor plays a key role in regulation of cortical function and cognition, appears to be the principal target for the hallucinogenic/psychedelic drugs such as lysergic acid diethylamide (LSD), and also is a target for the newest atypical...
A series of novel ligands for the serotonin 5-HT(2A/C) receptor subtype bearing the 2-phenylethylamine pharmacophore was synthesized and assayed for its 5-HT(2A) receptor binding affinity. As the 4'-aryl-substituted 2-(2,5-dimethoxyphenyl)ethylamines were previously unknown, an initial series of twelve compounds was chosen to obtain initial insight into their structure-activity relationships....
To date, several studies have demonstrated that phospholipase C-coupled receptors stimulate the production of endocannabinoids, particularly 2-arachidonoylglycerol. There is now evidence that endocannabinoids are involved in phospholipase C-coupled serotonin 5-HT(2A) receptor-mediated behavioral effects in both rats and mice. The main objective of this study was to determine whether activation...
J.C. Callaway, Charles S. Grob, Dennis J. McKenna, David E. Nichols, Alexander Shulgins, Kenneth W. Tupper; A Demand for Clarity Regarding a Case Report on the
A conformationally restricted analogue of mescaline, C-(4,5,6-trimethoxyindan-1-yl)-methanamine, was designed using a 5-HT(2A) receptor homology model. The compound possessed 3-fold higher affinity and potency than and efficacy equal to that of mescaline at the 5-HT(2A) receptor. The new analogue substituted fully for LSD in drug discrimination studies and was 5-fold more potent than mescaline....
The human serotonin 2A receptor (h5‐HT 2A R) plays an essential role in cognition, and is the principal target for serotonergic hallucinogens as well as atypical antipsychotics. Utilizing our in silico ‐activated h5‐HT 2A R homology model, an interaction was predicted between Asn343(6.55) in TM6 and the carbonyl of LSD. Virtual docking simulations of a new class of 5‐HT2 agonists, substituted N...
Experiments compared a series of phenethylamine hallucinogens with their phenylisopropylamine analogues for binding affinity and ability to stimulate serotonin 5-HT 2A receptor-mediated hydrolysis of phosphatidyl inositol in cells expressing cloned rat and human 5-HT 2A receptors. The (+/-)phenylisopropylamine analogues had significantly higher intrinsic activities for 5-HT 2A receptor-mediated...