Psychedelics Affect Far More Brain Cells Than Scientists Believed
Scientists at the University of Michigan have upended a foundational assumption about how psychedelic medicine works in the brain. The drugs alter not just a select group of neurons but the vast majority of them. This discovery could reshape treatment approaches for conditions from depression to Alzheimer’s disease.
New:Â Interested in Being Part of a Psychedelics-Focused Clinical Trial? Sign Up Here
| Key Takeaway | Detail |
|---|---|
| Traditional Theory Challenged | Psychedelics were thought to work only on neurons with serotonin 2A receptors in the frontal cortex |
| Actual Scope | Even neurons completely lacking these receptors show dramatic connectivity boosts after psychedelic treatment |
| Brain Region Identified | The retrosplenial cortex, critical for memory and orientation, lacks serotonin 2A receptors but still benefits from psychedelics |
| Medical Implications | Potential applications for Alzheimer’s disease and PTSD, not just depression |
| Research Method | Team used CRISPR gene editing to reveal new rules governing psychedelic effects on brain connectivity |
Looking for treatment? Find ketamine clinics closest to you as well as other psychedelic therapies in your area.
How Psychedelics Were Misunderstood
For decades, researchers presumed that psychedelics worked therapeutically by targeting the serotonin 2A receptor found on neurons in the frontal cortex. This assumption led psychedelic medicine to focus primarily on treating conditions related to frontal dysfunction, such as major depression. Omar Ahmed, the senior author and University of Michigan professor, noted this narrow view limited understanding of the drugs’ full potential.
The research team examined gene expression across the entire cortex. They identified brain regions lacking the serotonin 2A receptor that supposedly enabled psychedelic therapy to function. The retrosplenial cortex emerged as particularly revealing. This region, important for memory, orientation, and even imagining oneself in the future, was remarkably devoid of these receptors. It is also one of the first brain regions impaired in Alzheimer’s disease.
Surprising Results Emerge
When researchers recorded activity from neurons lacking serotonin 2A receptors, they found these cells also showed robust neuroplasticity after psychedelic treatment. More synapses formed, contradicting current assumptions about how psychedelic medicine works.
The team then employed CRISPR gene editing technology. This revealed new rules governing the surprising boost in brain connectivity. These rules do not require neurons to have serotonin 2A receptors themselves to receive a synaptic boost from psychedelics. The finding dramatically expands the number of brain connections that psychedelic medicine might potentially repair.
Dual Implications
Ahmed emphasized the discovery brings both caution and optimism. Caution, because it shows researchers must be wary of psychedelics acting on unintended neurons. Optimism, because it opens possibilities for using psychedelic compounds to restore brain connections in Alzheimer’s disease and other disorders involving the retrosplenial cortex, such as PTSD.
The study, published in Molecular Psychiatry, marks a significant shift in understanding. As Ahmed noted, the most successful medicines are those where scientists fully understand how they work. This research moves psychedelic therapy closer to that goal.
