Psilocybin helps the brain unlearn fear by silencing specific neural pathways
PsyPost••health
Key Points:
- A study published in Nature Neuroscience reveals that psilocybin facilitates fear unlearning by suppressing neurons encoding traumatic memories while recruiting new neurons to encode safety, specifically in the retrosplenial cortex, a brain region critical for memory and context association.
- Using a mouse model of trace fear conditioning, researchers found that psilocybin enhanced extinction of conditioned fear in a subset of animals ("responders") by rapidly silencing the "fear ensemble" of neurons and activating an "extinction ensemble," demonstrating bidirectional modulation of neural circuits.
- The study combined longitudinal single-cell calcium imaging and computational modeling to show that successful fear extinction requires active inhibition of fear neurons, allowing safety neurons to emerge and stabilize, rather than simply boosting learning capacity.
