MYCOLab Ai Logo - gold and army green

Molecular and Functional Imaging Studies of Psychedelic Drug Action in Animals and Humans

Summary

This comprehensive review examines how scientists use advanced imaging techniques like PET and SPECT scans to study how hallucinogenic drugs such as LSD and psilocybin interact with the brain. The research shows these drugs primarily bind to serotonin receptors, particularly the 5-HT2A subtype, which appear responsible for producing hallucinations. While scientific understanding of hallucinogen mechanisms has advanced significantly, there is still much to learn about their complete effects on brain chemistry and their potential therapeutic applications.

Background

Hallucinogens including LSD, psilocybin, mescaline, and DMT are compounds that evoke intense visual and emotional experiences. There is renewed research interest in hallucinogens driven by awareness of their psychotherapeutic potential. Molecular imaging techniques can depict the uptake and binding distribution of labeled hallucinogenic compounds in the brain.

Objective

To present a narrative review of the literature on hallucinogen binding in vitro and ex vivo, and various molecular imaging studies using PET or SPECT. The review aims to extract general principles from available results and identify topics for future research on hallucinogen action in the central nervous system.

Results

Early PET studies with N1-([11C]-methyl)-2-bromo-LSD confirmed majority of binding was to serotonin 5-HT2A receptors. Recent studies with [11C]Cimbi-36 showed preferential uptake in cortical regions with binding ratios ranging from 0.25 in striatum to 1.7 in cortical regions. Despite maturation of radiochemistry, only a handful of PET or SPECT studies exist on radiolabeled hallucinogens.

Conclusion

Hallucinogens primarily act as agonists at serotonin 5-HT2A receptors, though interactions at other receptors contribute to overall psychopharmacology. Considerable scope remains for basic imaging research on hallucinogen interactions and cerebrometabolic effects. Hybrid imaging combining PET with fMRI should provide useful insights for future research on hallucinogen action.
  • Published in:Molecules,
  • Study Type:Review,
  • Source: PMID: 33922330, DOI: 10.3390/molecules26092451
Scroll to Top