Biomaterial Database

Nerve terminal effects of indoleamine psychotomimetics on 5-hydroxytryptamine. 1982

A E Halaris

The mode of action of indoleamine psychotomimetics has been closely linked to 5-HT. Early work showed increases in rat brain levels of 5-HT which were later localized to the nerve-ending fraction. With improved methodology, the 5-HT increment was further detected in the synaptic vesicle fraction. These effects were obtained with several indoleamine hallucinogens but not with mescaline. LSD has been most thoroughly studied and has served as the prototypical compound in ascertaining the mode of action of these drugs. Pretreatment with reserpine abolished the 5-HT effects of LSD in the vesicular fraction. However, a new compartment, termed "juxtavesicular," displayed 5-HT increases following reserpine and LSD. A soluble binding site for 5-HT within the synaptoplasm has been postulated in confirmation of independent results by other groups of investigators. The origin of the 5-HT increment appears to be associated with newly synthesized amine. This was deduced from experiments involving various 5-HT synthesis blockers. To ascertain whether inhibition of raphé neuronal firing is responsible for the accumulation of 5-HT at the nerve terminal, two sets of experiments were performed. Destruction of the raphé cell bodies by radiofrequency lesions failed to abolish the LSD-induced 5-HT increase early after the lesion. Destruction of cortical 5-HT neurons with the neurotoxin 5,7-dihydroxytryptamine completely abolished the 5-HT effect of LSD. It was concluded that an intact nerve terminal is necessary for the expression of the LSD-mediated increases in 5-HT. A LSD "autoreceptor" is postulated, possibly identical to a 5-HT presynaptic receptor inhibiting the release of 5-HT.

UI	MeSH Term	Description	Entries
D007211	Indoles	Benzopyrroles with the nitrogen at the number one carbon adjacent to the benzyl portion, in contrast to ISOINDOLES which have the nitrogen away from the six-membered ring.
D008238	Lysergic Acid Diethylamide	Semisynthetic derivative of ergot (Claviceps purpurea). It has complex effects on serotonergic systems including antagonism at some peripheral serotonin receptors, both agonist and antagonist actions at central nervous system serotonin receptors, and possibly effects on serotonin turnover. It is a potent hallucinogen, but the mechanisms of that effect are not well understood.	LSD,Lysergide,LSD-25,Lysergic Acid Diethylamide Tartrate,Acid Diethylamide, Lysergic,Diethylamide, Lysergic Acid,LSD 25
D009474	Neurons	The basic cellular units of nervous tissue. Each neuron consists of a body, an axon, and dendrites. Their purpose is to receive, conduct, and transmit impulses in the NERVOUS SYSTEM.	Nerve Cells,Cell, Nerve,Cells, Nerve,Nerve Cell,Neuron
D011562	Psilocybin	The major of two hallucinogenic components of the sacred Teonanacatl mushrooms (see PSILOCYBE), the other component being PSILOCIN.	1H-Indol-4-ol, 3-(2-(Dimethylamino)ethyl)-, Dihydrogen Phosphate (ester),Psilocybine,Psilocibin
D011903	Raphe Nuclei	Collections of small neurons centrally scattered among many fibers from the level of the TROCHLEAR NUCLEUS in the midbrain to the hypoglossal area in the MEDULLA OBLONGATA.	Caudal Linear Nucleus of the Raphe,Interfascicular Nucleus,Nucleus Incertus,Rostral Linear Nucleus of Raphe,Rostral Linear Nucleus of the Raphe,Superior Central Nucleus,Central Nucleus, Superior,Incertus, Nucleus,Nuclei, Raphe,Nucleus, Interfascicular,Nucleus, Raphe,Nucleus, Superior Central,Raphe Nucleus
D012110	Reserpine	An alkaloid found in the roots of Rauwolfia serpentina and R. vomitoria. Reserpine inhibits the uptake of norepinephrine into storage vesicles resulting in depletion of catecholamines and serotonin from central and peripheral axon terminals. It has been used as an antihypertensive and an antipsychotic as well as a research tool, but its adverse effects limit its clinical use.	Raunervil,Raupasil,Rausedil,Rausedyl,Serpasil,Serpivite,V-Serp,V Serp
D001923	Brain Chemistry	Changes in the amounts of various chemicals (neurotransmitters, receptors, enzymes, and other metabolites) specific to the area of the central nervous system contained within the head. These are monitored over time, during sensory stimulation, or under different disease states.	Chemistry, Brain,Brain Chemistries,Chemistries, Brain
D002027	Bufotenin	A hallucinogenic serotonin analog found in frog or toad skins, mushrooms, higher plants, and mammals, especially in the brains, plasma, and urine of schizophrenics. Bufotenin has been used as a tool in CNS studies and misused as a psychedelic.	Dimethylserotonin,Mappine,5-Hydroxy-N,N-dimethyltryptamine,Bufotenine,Mappin,N,N-Dimethyl-5-hydroxytryptamine,5 Hydroxy N,N dimethyltryptamine,N,N Dimethyl 5 hydroxytryptamine
D004130	N,N-Dimethyltryptamine	An N-methylated indoleamine derivative and serotonergic hallucinogen which occurs naturally and ubiquitously in several plant species including Psychotria veridis. It also occurs in trace amounts in mammalian brain, blood, and urine, and is known to act as an agonist or antagonist of certain SEROTONIN RECEPTORS.	Dimethyltryptamine,N,N Dimethyltryptamine
D006213	Hallucinogens	Drugs capable of inducing illusions, hallucinations, delusions, paranoid ideations, and other alterations of mood and thinking. Despite the name, the feature that distinguishes these agents from other classes of drugs is their capacity to induce states of altered perception, thought, and feeling that are not experienced otherwise.	Hallucinogen,Hallucinogenic Agent,Hallucinogenic Drug,Hallucinogenic Substance,Psychedelic,Psychedelic Agent,Psychedelic Agents,Psychotomimetic Agent,Psychotomimetic Agents,Hallucinogenic Agents,Hallucinogenic Drugs,Hallucinogenic Substances,Psychedelics,Agent, Hallucinogenic,Agent, Psychedelic,Agent, Psychotomimetic,Agents, Hallucinogenic,Agents, Psychedelic,Agents, Psychotomimetic,Drug, Hallucinogenic,Drugs, Hallucinogenic,Substance, Hallucinogenic,Substances, Hallucinogenic