Hallucinogens (for exam 3)

PSYC 733

which drugs act as hallucinogenic drugs?

• LSD

• Mescaline

• Psilocybin

• DMT

• 5 MEO-DMT (synthetic DMT)

what are the 2 major neuromodulatory systems involved in the mechanism of action?

• serotonergic

• noradrenergic

what receptors mediate the interoceptive effects of LSD?

5-HT2A receptors

what hallucinogenic drugs have also been used in religious ceremonies?

• Mescaline

• Psilocybin

• Salvinorin A / Salvia

who discovered LSD and what type of drug was he trying to develop?

• Albert Hofmann

• trying to find a new respiratory stimulant

list the hallucinogens from most potent to least potent with their trip durations

1. LSD: 6-12 hr

2. 251-NBOMe

3. Psilocybin: <12 hr

4. Mescaline: 6-12 hr

5. DMT: <1 hr

6. Salvinorin A: ~15 min

what are the stages of a typical trip and what happens at each stage?

1. onset: 0.5-1 hr after ingestion (visual effects start)

2. plateau: 2 hours (time slows, visual effects intesnify)

3. peak: 3 hrs (distorded images, synesthesia, depersonalization, euphoria, anxiety, pupil dilation, increase hr/bp/temp)

4. come down: 2 hrs

what are the common effects of hallucinogens?

• altered perceptions

• visual distortions

• synesthesia

• changes in mood

• heightened emotional experiences

• hallucinations

what do ketamine users report experiencing?

• sensations of light/colorful visions

• loss of time sense

• body distortions

• altered perception of body consistency (body is made of wood)

• sensations of floating/hovering

• leaving their body

• insights into the mysteries of existence

• being at one with the universe

• visions of spiritual or supernatural beings

why is ketamine used? What differentiates ketamine from other drugs used for the same purpose?

• used as an anesthetic in animals and kids

• dissociative anesthesia (retain muscle tone and eyes open while anesthetized)

what are the side effects of PCP? what are the risks of high doses?

• agression/violence

• disorientation

• hallucinations

• respiratory depression

• risk of overdose

how do hallucinogenic drugs alter the cerebral cortex?

• 5HT2A receptors modulate LC activity

• serotonergic neurons in spinal cord (raphe nucleus) talk to pyramidal cells in PFC and deep cortex (layer 5)

what is the mechanism of action of PCP, ketamine, and dextrophan?

non-competetive antagonists at NMDA receptors

• binds to a different receptor than Glutamate, but blocks the channel from opening