Hallucinogens Flashcards
What are hallucinogens?
Induce an altered state of consciousness, characterised by distortions of perception, hallucinations or visions.
What are the 2 types of hallucinogens?
Classical hallucinogens.
Dissociative anaesthetics
What are classical hallucinogens?
Include plat-derived substances and synthetic drugs - agonists at serotonin receptors.
What are dissociative anaesthetics?
Synthetic drugs that produce anaesthesia at higher doses and altered states of consciousness at lower doses.
they are non-competitive NMDA receptor antagonist.
What is the scale called that is used to quantify hallucinogens on their states of consciousness?
Five-dimensional altered state of consciousness rating scale.
What are the 5 dimensions that make up the 5DASC?
Oceanic boundlessness - positively experiences loss of ego boundaries.
Anxious ego- disintegration -thought disorder and loss of self-control
Visionary restructuralisation - perceptual alterations
Acoustic alterations
Altered vigilance.
Why is it important to set expectations when determining the subjective experience induced by hallucinogens?
The effects are dependent on the users expectations and the environment.
they amplify what is already in the mind.
Describe the mechanisms of action involved in classical hallucinogens.
They have a high affinity for serotonin.
they are g-protein couple receptors so their activation mainly has stimulatory effects on the neuron. The activation my stimulate excitatory neurons including in the prefrontal cortex which may be critical for hallucinogenic effects.
Describe the mechanisms of action for MDMA.
Stimulates serotonin release as well as DA release in the nucleus accumbens which is thought to contribute to reinforcing properties.
Describe the mechanisms of dissociative anaesthetics.
The NMDA blockade receptor increases neural excitation in many brain and cortical regions.
NMDA antagonist stimulate the prefrontal cortex and nucleus accumbens DA release and this effect is mediated by the increased neural excitation in cortical regions.
Why is prefrontal activation critical for the psychological effects of classical hallucinogens?
Stimulate serotonin 2A receptors in cortical excitatory regions which leads to stimulation of excitatory neurons and increased activation in cortical areas.
Why is prefrontal activation critical for the psychological effects of dissociative anaesthetics?
NMDA antagonists block the NMDA receptors reducing the activity of inhibitory interneurons which leads to disinhibitions of excitatory neurons in cortical regions = increased activity of excitatory neurons
