Hallucinogens Lecture Notes Review

Vocabulary flashcards covering the history, classifications, behavioral effects, and neuropharmacological mechanisms of hallucinogenic substances like LSD, psilocybin, and MDMA.

Hallucinogens

A group of substances that produce changes in thought, perception, and/or mood, with a name derived from the Latin alucinari, meaning “to wander in the mind”.

Psychedelics

A term for hallucinogens meaning “liberation of mind”.

Entheogens

A term for hallucinogens meaning “bringing out the inner god”.

Indolealkylamines

A class of hallucinogens structurally similar to serotonin ($5-HT$), which includes substances such as $LSD$, psilocybin, and $DMT$.

Phenylethylamines

A class of hallucinogens structurally similar to dopamine and norepinephrine, including substances such as mescaline and $MDMA$.

LSD (Lysergic acid diethylamide)

A potent indolealkylamine synthesized in 1938 by chemist Albert Hoffman from the ergot fungus; it is typically taken via blotter paper or liquid.

Ergotism

A condition caused by the ergot fungus characterized by a burning sensation in limbs due to vasoconstriction, gangrene, convulsions, and hallucinations.

Delysid

The trade name for $LSD-25$ when it was marketed by Sandoz in 1946 for analytical psychotherapy and experimental studies on psychoses.

Project MK-ULTRA

A $CIA$ program (1953-1964) that conducted human experiments, often without consent, into mind control and interrogation methods using $LSD$.

Timothy Leary

A Harvard psychology lecturer in the 1960s who promoted the use of psilocybin and $LSD$ with the slogans “Turn on, tune in, drop out” and “Set and setting”.

Synesthesia

A perceptual phenomenon occurring during the peak of an $LSD$ trip where senses blend, such as “seeing sounds”.

Hallucinogen Persisting Perception Disorder (HPPD)

A condition involving continuous visual disturbances, such as seeing halos or trails, that can persist for weeks or years after drug use.

Psilocybin

The active ingredient in “magic” mushrooms, which is converted to psilocin in the body and produces effects similar to $LSD$ but for a shorter duration ($4-7 ext{ hours}$).

Magic Truffles

The subterranean sclerotium of mushrooms like Sclerotium Tampenensis, which contain psilocybin and are often sold in “smart shops”.

Mescaline

A naturally occurring phenylethylamine found in the peyote cactus, used for over 5000 years and currently permitted for religious use in the Native American Church.

Empathogen

A term used to describe the effects of $MDMA$, characterized by a sense of euphoria, increased empathy, and feelings of closeness with others.

Alexander Shulgin

The chemist known as the “reinventor of $MDMA$” who created more than 300 psychoactive compounds in his home-based lab.

$5-HT_{1A}$ receptors

Inhibitory serotonin autoreceptors in the Raphe Nuclei that $LSD$ binds to, though their inhibition is not directly responsible for hallucinogenic effects.

$5-HT_{2A}$ receptors

Excitatory serotonin receptors identified as the primary mechanism for hallucinogenesis; agonists of these receptors induce the “head twitch response” in mice.

Head twitch response

A behavioral response in mice (similar to a wet dog shake) that is induced by $5-HT_{2A}$ agonists and is missing in $5-HT_{2A}$ knockout mice.

SERT (Serotonin Transporter)

The primary target of $MDMA$, which enters the synaptic terminal via this transporter and reverses its function to release $5-HT$ into the synaptic cleft.

Oceanic boundlessness

A subjective effect of $MDMA$ and psilocybin characterized by derealization, depersonalization, positive mood, and an altered sense of time.

Anxious ego-dissolution

A subjective effect involving thought disorder and loss of autonomy associated with fear and anxiety.

Visionary restructuralization

A category of subjective drug effects including auditory and visual illusions, hallucinations, and synesthesia.

Layer V pyramidal neurons

Neurons in the prefrontal cortex where a high density of $5-HT_{2A}$ receptors are located; their preferential activation is a proposed mechanism for hallucinogenesis.