Psilocybin and Neuroplasticity: How Mushrooms Rewire the Brain

## The Short Answer Psilocybin produces the most dramatic neuroplasticity effects of any known compound. A 2021 study published in *Neuron* found that a single psilocybin dose produced a **10% increase in dendritic spine density** in the prefrontal cortex of mice — changes that persisted for at least one month. Brain imaging studies in humans show psilocybin disrupts the default mode network (DMN), increases neural entropy (brain flexibility), and creates new patterns of connectivity that persist weeks after the experience. ## What Neuroplasticity Means Neuroplasticity is the brain's ability to form new neural connections and reorganize existing ones. It is the biological basis of learning, recovery from trauma, and therapeutic change. Most antidepressants have modest neuroplasticity effects. Psilocybin's effects are orders of magnitude larger. ## The Dendritic Spine Study A 2021 study by Shao et al. in *Neuron* gave mice a single dose of psilocybin and measured dendritic spine density (the physical connections between neurons) in the prefrontal cortex: - 10% increase in dendritic spine density within 24 hours - New spines were larger and more stable than baseline - Changes persisted for at least 1 month - Behavioral improvements in stress resilience correlated with spine density increases ## Default Mode Network Disruption The default mode network (DMN) is a set of brain regions active during self-referential thought, rumination, and mind-wandering. It is hyperactive in depression, anxiety, addiction, and OCD. Psilocybin temporarily disrupts DMN activity, creating a window of increased neural flexibility during which new patterns can be established. [See the protocol →](/research-checkout) *This article is for informational purposes only and does not constitute medical advice.*