Psilocybin Synthesis in 4 Steps & How Magic Mushrooms Rewire Brain Networks (Psychedelic Science)

Key Concepts

Notes

Historical Background

• Human use of psilocybin mushrooms dates to prehistoric times (possibly 7,000–9,000 BCE based on Algerian cave art)
• Aztec name for mushrooms roughly translates to "God's flesh"
• European prohibition in the 16th century drove use underground; by the early 20th century, Western academics doubted psychoactive mushrooms existed
• R. Gordon Wasson (JP Morgan banker) traveled to Mexico in 1953, participated in mushroom ceremonies, and published the first widely distributed article on magic mushrooms in *Life* magazine (1957)
• Botanist Roger Heim grew Mexican mushrooms in Paris and shared samples with Sandoz (Switzerland)
• **Albert Hofmann** isolated psilocybin and psilocin at Sandoz and developed the first synthesis in 1958–1959
• Sandoz distributed 2 mg tablets, nucleating 1960s–70s clinical studies
• Classified Schedule I during the War on Drugs; clinical research resumed in the 2000s
• FDA granted **Breakthrough Therapy Designation** in 2018

Hofmann's Self-Experiment with Mushrooms

• Animal testing (mice, dogs) was inconclusive — animals less sensitive to psychedelics than humans
• Hofmann ate 32 medium-sized mushrooms
• Effects began ~30 minutes later; peak at ~90 minutes; total duration ~6 hours
• Key insight: potency was not the problem — animals simply respond differently than humans
• This led to human-guided bioassay testing to complete the isolation

Chemical Structure & Mechanism of Action

• Psilocybin shares the **tryptamine core** with serotonin, melatonin, and DMT
• Psilocybin is a prodrug: dephosphorylated in intestine/liver under acidic conditions → psilocin
• Psilocin is less hydrophilic → can cross the blood-brain barrier
• Psilocin binds 5-HT2A selectively, but affinities for 2C and 1A subtypes are similar in magnitude — picture is complex
• 5-HT2A receptors are **GPCRs**; activation triggers downstream signaling cascades involving glutamate and other neurotransmitters
• These cascades lead to structural and functional cellular changes → **enhanced neuroplasticity**
• Acute effects (4–6 hours, peak 60–90 min) are separate from slower, more durable cellular changes

Neuroplasticity Evidence

• Mouse study: psilocybin caused significant increase in **dendritic spine density and size** in the frontal cortex
• A fraction of new dendritic spines persisted **one month later**, indistinguishable from normal spines — clear structural evidence
• Twist: pre-treating mice with **ketanserin** (5-HT2A antagonist) blocked the head-twitch response but **did not prevent** structural remodeling
• Suggests remodeling may occur at lower psilocin concentrations or via mechanisms beyond 5-HT2A

4-Step Synthesis (Usona Institute Route)

• Scaled to **1.2 kg of psilocybin** in a single batch for clinical trial supply
• Phosphorylation step remains the most problematic: required 3 kg of Celite to prevent sticky precipitate; hydrolysis quenched in cold THF/water with excess triethylamine; held at sub-zero for ~60 min; longer hold times cause decomposition back to psilocin
• Final product isolated by recrystallization at high purity
• Hofmann's route: benzyl-activated phosphate with intramolecular N-migration → hydrogenation; poorly understood migration step; bad atom economy (700 g psilocin → 100 g product); temperature/volume-sensitive; scale-up issues (6-day filtrations)
• Usona route: cleaner, scalable, kilogram-capable

Clinical Evidence

• Randomized study: ~50 heavy drinkers per cohort receiving psilocybin or sedative (quasi-placebo) alongside psychotherapy
• Psilocybin group had significantly lower alcohol use at 6-month follow-up, with fewer alcohol-related problems
• Three arms: 25 mg, 10 mg, 1 mg (active control)
• 60–80% of enrollees severely depressed; ~80% had failed ≥2 prior treatments; <10% had prior psilocybin experience
• Administered in calm supervised setting with curated playlist; supported by targeted psychotherapy
• **Results**: 10 mg showed no significant difference from 1 mg control; **25 mg group** showed mean ~12-point drop in MADRS depression score
• ~30% of 25 mg patients reached remission (score <10) at 12 weeks — meaningful for TRD
• Safety: more adverse events in 25 mg group, primarily headaches and nausea; no significant increase in serious AEs (e.g., suicidal ideation)
• Limitations: true double-blinding nearly impossible (participants and staff know who is tripping); larger and longer trials needed

Brain Network Effects

• 2022 fMRI study: two psilocybin doses + psychotherapy in severely depressed patients
• Psilocybin significantly **decreased brain network modularity** (networks became less isolated from each other)
• **DMN activation decreased**; its integration with executive and salience networks **increased**
• Net effect: increased cognitive flexibility — directly contrasts the rigid, constricted network connectivity characteristic of depression
• SSRI comparator arm **lacked** this network integration effect
• Proposed mechanism: psilocybin's specificity for 5-HT2A receptors (highly expressed in regions underlying these networks) vs. broader serotonin reuptake inhibition

Additional Brain Regions of Interest

• **Amygdala**: Reduced response under psilocybin; pivotal in depression
• **Claustrum**: Thin sheet of neurons in central cortex; high 5-HT2A expression; highly interconnected; involved in attention and task switching
• Psilocybin **decreases claustrum activity** — may explain resetting of rigid thought patterns and emergence of new psychological insights
• **Anterior cingulate cortex thickness**: Predicts the emotional quality of a psilocybin experience (e.g., bliss, unity); one of many factors explaining individual variation in psychedelic response

Quotes Worth Keeping

Depression can be characterized by abnormally constricted network connectivity — psilocybin might ameliorate this by broadening mental states.

A fraction of these new dendritic spines was still present after a month and seemed no different than normal spines — clear evidence for structural change from psychedelics.

The structural remodeling took place nevertheless [after 2A receptor blockade] — it might proceed via other mechanisms beyond serotonin 2A receptors.