Hallucinogens

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Do curso por Emory University

O Cérebro dos Dependentes

1170 classificações

Emory University

O Cérebro dos Dependentes

1170 classificações

Este curso abordará a dependência de drogas e outros comportamentos. Veremos o que acontece no cérebro e como essa informação nos ajuda a lidar e superar a dependência. Também serão discutidos outros tópicos como política de governo e vulnerabilidade ao uso de drogas.

Na lição

Classes of Drugs, Part 1

Psychostimulants7:32

Hallucinogens4:38

Opiate Drugs6:41

Sedatives, Anti-Anxiety Agents, & Hypnotics6:23

Conheça os instrutores

Michael Kuhar, Ph.D.
Professor
Yerkes/Emory Pharmacology and Neuroscience

This lecture is devoted to the hallucinogens.

The hallucinogens are drugs that alter

consciousness by inducing sensory and perceptual disturbances.

The user can experience a distortion of something.

Or perhaps, even something that isn't there at all.

Data show that hallucinogens have been used by more

than 14% of the population, age 12 or older.

There are two general categories of

hallucinogens, and I'll discuss them separately.

The first category is the Phencyclidine.

Known as PCP, or angel dust.

Or other PCP types of hallucinogens.

The image shows the structure of PCP.

And the structure of another, similar compound, called ketamine.

These compounds are called dissociative anesthetics.

They're called that because they produce feelings of separation of mind and body.

Quite an interesting but scary effect.

Intravenous administration can cause a schizophrenic like state, with

psychosis and catatonia, which is a stuporous, immobile state.

These drug effects can lead to injuries

from accidents, fights, falls, and many other things.

Animal research and testing strongly suggests that PCP is addicting.

Intoxication from PCP use also includes disorientation,

confusion, hallucinations, delusions, and coma at high doses.

It's easy to see that this is a very toxic substance

that renders an individual fairly incapable

of functioning in the real world.

How does it work in the brain?

PCP interferes with the major excitatory neurotransmitter, glutamate.

It inhibits glutamate neurotransmission at a subtype of receptor,

which is the NMDA subtype of glutamate receptor.

PCP blocks that receptor.

Now let's consider the other hallucinogens, which

comprise a very diverse group of substances.

Here we see LSD, also known as acid, and MDMA, also known as

Molly, or ecstasy, an there are others listed, as well.

LSD produces visual hallucinations that can be

frightening, and have sometimes led to suicide.

LSD can also cause a persistent perceptual

experience, even when the drug is not present.

This can be a very worrisome, and disabling experience.

The mechanism of LSD appears to be related to serotonin receptors,

presumably by stimulating the serotonin 2A subtype of receptor.

But, additional mechanisms are probably also in play.

MDMA, or ecstasy, is both a stimulant and a hallucinogen.

It's been used in psycho therapy, where it's thought to produce insights

and self-knowledge, but most people feel that this has not been adequately proven.

What are the neurotoxicities of MDMA, that we've talked about?

And another substance called MDA?

[SOUND] In animal studies, these substances cause a degeneration of nerve

terminals of neurons, containing the nerve transmitter serotonin.

So they can me neuronaly destructive, certainly at higher doses.

And there's evidence that this occurs, at least partly, in human beings as well.

This is not a minor toxicity.

In summary, hallucinogens can be divided into two major groups.

The PCP type, and the other types that include LSD.

They have different mechanisms in brain,

sometimes complex mechanisms, and sometimes complex actions.

In addition to the acute problem of

perceptual distortion, they have some other serious toxicities

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