How Lion's Mane Supports Synaptic Plasticity

Lion's Mane and Neuroplasticity

ERK1/2 pan-neurotrophic pathway

Hericerin derivatives from Lion's Mane fruiting bodies drove extensive neurite outgrowth and branching in hippocampal neurons through a pan-neurotrophic pathway converging on ERK1/2 signaling, and enhanced spatial memory in mice.

Martínez-Mármol et al., Journal of Neurochemistry, 2023

ERK1/2 → CREB

the signaling pathway linking Lion's Mane to long-term potentiation

Dual source

hericenones (fruiting body) and erinacines (mycelium) use different pathways

1 hour

time to Stroop task improvement in the 2025 acute-dose double-blind RCT

Martínez-Mármol et al., Journal of Neurochemistry, 2023

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Most coverage of Lion's Mane focuses on nerve growth factor, which is true but incomplete. The compounds in Lion's Mane fruiting bodies that have drawn the most recent research attention, hericerin derivatives, do not just stimulate one growth factor. They act through a pan-neurotrophic pathway, converging on a single intracellular signaling step, in the hippocampal neurons where memory and learning are encoded.

That finding, from Martínez-Mármol and colleagues in 2023, changed the mechanistic story for Lion's Mane and lion's mane synaptic plasticity specifically.^[6] Synaptic plasticity is the brain's capacity to strengthen, weaken, and form new connections in response to experience. It is what learning and memory are built from at the cellular level. This article maps the research on exactly how Lion's Mane supports that process, from the compounds involved to the cellular changes they produce.

For the broader context on Lion's Mane and brain health, the complete Lion's Mane guide covers the full research profile.

What Synaptic Plasticity Is, and Why Its Molecular Basis Matters

Synaptic plasticity is the ability of synapses, the connection points between neurons, to change their strength over time in response to activity. A synapse that fires repeatedly becomes stronger (a process called long-term potentiation, or LTP). A synapse that goes unused can weaken or be eliminated. New synapses can form between neurons that weren't previously connected.

Every memory you form, every skill you build, every association your brain makes involves this process at the cellular level. Synaptic plasticity is not a metaphor for learning; it is the molecular substrate of learning.

The cellular events involved are specific: neurites (the branching arms of neurons) grow and extend toward other cells, growth cones at the tips of those neurites make contact and form synaptic junctions, and repeated activation of those junctions drives the molecular changes that make connections permanent. Inside the neuron, signaling cascades relay the activity signal into the nucleus, where they activate gene expression programs that manufacture the proteins needed to maintain strong synapses.

Understanding how Lion's Mane affects synaptic plasticity means tracing exactly where in this process its compounds act and what changes result.

The Step-by-Step Mechanism: How Lion's Mane Compounds Reach Synapses

The pathway from mushroom extract to synaptic change involves several specific steps.

How Lion's Mane drives synaptic plasticity:

1. Bioactive compounds (hericenones from fruiting body; erinacines from mycelium) enter the body orally and, in the case of erinacines, cross the blood-brain barrier directly.
2. Hericenones stimulate production of neurotrophins (NGF in particular, demonstrated in human astrocytoma cells) in brain cells and astrocytes, and hericerin derivatives act through a broader pan-neurotrophic pathway; erinacines stimulate BDNF specifically via a different intracellular route.
3. Neurotrophins bind to surface receptors on neurons (TrkA binds NGF; TrkB binds BDNF). These receptors are proteins that sit on the neuron's surface and translate the neurotrophin signal into internal activity.
4. Receptor activation triggers a signaling enzyme called ERK1/2 (extracellular signal-regulated kinase), which relays the neurotrophin signal from the cell surface into the nucleus.
5. ERK1/2 phosphorylates CREB (cAMP response element-binding protein), a gene-regulating protein. When CREB is activated this way, it switches on genes that produce proteins required for synaptic strengthening and new connection formation.
6. These proteins support growth cone expansion, neurite outgrowth, and the molecular consolidation of strengthened synaptic connections (LTP).

This is the mechanistic chain. Each step has research support, and the chain connects Lion's Mane consumption to changes that are specific enough to measure in cells and tissues.

Hericenones and Pan-Neurotrophic Activation: A Broader Signal Than NGF Alone

Growth cones are the structures at the tips of growing neurites where new synaptic contacts are established. Think of them as the exploring heads of a neuron, reaching toward potential connection points. Neurites that grow longer and branch more have more opportunities to make contact with neighboring cells, which translates to more potential new synapses.

Martínez-Mármol and colleagues purified hericerin derivatives (compounds derived from the fruiting body of Lion's Mane, including N-de phenylethyl isohericerin and its derivative hericene A) and tested them in cultured hippocampal neurons.^[6] The result was notable: these compounds promoted extensive axon outgrowth and neurite branching, even in serum-free conditions, demonstrating potent neurotrophic activity. The effect converged on ERK1/2 signaling, and the researchers found it operated at least partly independently of the classic TrkB (BDNF) receptor, indicating a complementary neurotrophic route rather than NGF signaling alone.

This "pan-neurotrophic" activation is important for two reasons. First, it shows Lion's Mane compounds can drive neuronal growth through more than one receptor pathway, producing a broader neuroplasticity signal than activating NGF alone. Second, the convergence on ERK1/2 means these parallel inputs feed into a common downstream amplification step inside the neuron. In the same study, mice fed Lion's Mane crude extract and hericene A showed increased neurotrophin expression, downstream signaling, and significantly enhanced hippocampal memory, connecting the cellular mechanism to a behavioral outcome.

The foundational NGF-inducing research by Mori and colleagues in 2008 established that Lion's Mane compounds stimulate NGF synthesis in 1321N1 human astrocytoma cells.^[1] The Martínez-Mármol 2023 paper extended this story: the neurotrophic effect is not limited to NGF signaling, and it acts on the hippocampal neurons most relevant to spatial memory and learning.

For a detailed account of how hericenones specifically drive NGF synthesis, the hericenones and NGF synthesis article covers that mechanism in depth.

Erinacines and the BDNF Pathway: A Different Route to the Same Result

The erinacines are a separate class of compounds found primarily in Lion's Mane mycelium. They are smaller molecules than many of the hericenones, which matters practically: erinacines can cross the blood-brain barrier directly, rather than needing to stimulate production of large neurotrophin proteins that then act at specific sites.

Chiu and colleagues demonstrated in 2018 that erinacine A specifically activates the BDNF pathway through a signaling chain involving three enzymes: PI3K, Akt, and GSK-3beta.^[3] BDNF (brain-derived neurotrophic factor) is the dominant neurotrophin in the adult hippocampus and cortex, and this enzyme chain relays BDNF's signal into the nucleus, regulating neuronal survival and synaptic function.

Li and colleagues' 2018 comprehensive review of erinacine-enriched mycelium documented that this BDNF pathway drives a range of neuroplasticity outcomes across preclinical models: cognitive improvement, neuroprotection, and support for learning and memory processes.^[4]

The dual-pathway picture matters for product selection. Fruiting body extracts are richer in hericenones (the pan-neurotrophic ERK1/2 pathway). Mycelium extracts are richer in erinacines (the BDNF/PI3K/Akt/GSK-3beta pathway). Both converge on neuroplasticity outcomes but through different molecular routes. The erinacine route also has direct brain access through the blood-brain barrier, a relevant advantage for central nervous system effects.

For the detailed explanation of why erinacines can reach the brain directly, the erinacines and the blood-brain barrier article covers that specific property.

Neurite Outgrowth: The Structural Evidence of New Connection Formation

Beyond the signaling cascade, synaptic plasticity has a structural component: neurons must physically grow and extend new processes to form new connections. Neurite outgrowth is the term for this growth, and it has been measured directly in Lion's Mane research.

Lai and colleagues tested Lion's Mane aqueous extract in cultured NG108-15 neuronal cells and documented promotion of neurite outgrowth, including a synergistic effect with NGF.^[2] This is structural evidence: not just a change in biochemical signals, but a physical change in the shape and extent of neurons: longer processes, more branching, more potential connection sites.

Neurite outgrowth is the structural substrate that the signaling cascades produce. When ERK1/2 activates CREB and the gene expression programs that follow, some of the proteins produced support cytoskeletal rearrangement inside the neurite, allowing it to extend further. When erinacines stimulate the BDNF/Akt pathway, part of the result is also promotion of this structural growth.

Szucko-Kociuba and colleagues' 2023 neurotrophic review synthesized this evidence alongside the broader mechanistic framework, documenting that neurite outgrowth and neuroprotection are complementary outcomes of the same underlying neurotrophic signaling.^[7] A 2025 comprehensive narrative review by Contato and colleagues confirmed this synthesis, placing Lion's Mane's neurite-promoting effects within the broader neuroprotection story that includes antioxidant and anti-inflammatory contributions to maintaining the environment in which synaptic plasticity can occur.^[8]

The CREB-LTP Bridge: When Synaptic Change Becomes Lasting Memory

Long-term potentiation (LTP) is the most studied form of synaptic plasticity in the context of memory formation. When a synapse is repeatedly stimulated in a short window, it undergoes a lasting change that makes future activation of the same synapse easier; the connection becomes stronger and more reliable. This is, at the cellular level, what it means for information to be stored in the brain.

CREB, the transcription factor that ERK1/2 activates, is directly required for LTP. When CREB is phosphorylated (activated) by the ERK1/2 signal, it switches on gene expression programs that produce the proteins needed to consolidate a temporarily strengthened synapse into a permanently strengthened one. Without CREB activation, synaptic strengthening is transient rather than lasting.

Spangenberg and colleagues' 2025 systematic review on erinacines drew this connection directly, linking erinacine-mediated activation of pro-survival signaling and CREB to long-term potentiation, the cellular process associated with learning and memory, and to the amelioration of cognitive and behavioral deficits in disease models.^[9] Across the cellular and rodent studies it synthesized, the review found erinacines enhanced neurogenesis and improved cognitive outcomes, supporting the mechanistic chain from Lion's Mane to LTP.

Chong and colleagues provided related evidence in 2021: in a mouse model, they pharmacologically blocked neurogenesis and showed this also blocked Lion's Mane's antidepressant effects.^[5] This causal connection between Lion's Mane, neurogenesis (itself driven by BDNF and synaptic plasticity mechanisms), and functional outcomes is the most direct evidence of the biological chain in a living system.

For the full treatment of the LTP mechanism and how it connects to memory consolidation, the Lion's Mane and long-term potentiation article goes into the cascade in detail.

The Acute Evidence: Why 1-Hour Improvement Points to Synaptic Modulation

Most of the research above describes processes that take days to weeks: gene expression changes, new protein synthesis, physical neurite growth. These are real, but they explain long-term supplementation effects rather than what happens quickly.

The 2025 double-blind, randomized, placebo-controlled trial by Surendran and colleagues changed this picture.^[10] In healthy young adults, a single dose of standardized Lion's Mane extract produced significantly faster performance on the Stroop task (a test requiring attention, processing speed, and inhibitory control) measured just one hour later.

One hour is too short for the genomic effects of CREB activation to translate into new protein synthesis or structural neurite growth. The acute effect must come from something faster. The most likely candidates are direct neurotransmitter or synaptic membrane effects: changes in receptor sensitivity, neurotransmitter release probability, or synaptic inhibition dynamics that can shift in minutes rather than weeks.

This does not invalidate the longer-term mechanistic picture; it extends it. Lion's Mane appears to support synaptic function through both fast mechanisms (likely direct neurochemical effects on existing synapses) and slow mechanisms (neurotrophic signaling, CREB activation, new synapse formation, neurogenesis). The 1-hour RCT result is the most acute human evidence, and it suggests the synaptic effects of Lion's Mane compounds extend beyond the slower neuroplasticity timeline that has been the focus of most research.

The Epigenetic Frontier: Gene-Level Changes That May Outlast Supplementation

The most recent mechanistic proposal for how Lion's Mane supports synaptic plasticity comes from Cipriano and colleagues in a 2026 hypothesis-driven review.^[11] The review proposes that Lion's Mane bioactives operate through a "neurotrophic-epigenetic axis" involving non-coding RNA networks, specifically micro-RNAs and long non-coding RNAs that regulate gene expression without changing the DNA sequence itself.

This is distinct from the transcription factor story (ERK1/2 activating CREB) because epigenetic changes can persist for long periods after the stimulus is removed. If Lion's Mane compounds modify the epigenetic landscape around genes involved in synaptic plasticity, the changes in gene expression could continue even after supplementation stops.

This is hypothesis-driven science at this stage, not established mechanism. The Cipriano paper is framed as a proposed framework for future investigation, not a report of confirmed findings. But it addresses a question that the existing evidence raises: if the neurotrophic effects require ongoing supplementation (as the Mori 2009 RCT suggested, where scores declined after stopping),^[12] or if some effects persist, the epigenetic axis may be the mechanism worth investigating.

The Lion's Mane and BDNF article covers the circulating BDNF and pro-BDNF data from human studies. For the neurogenesis angle (a downstream consequence of the same synaptic plasticity mechanisms), the neurogenesis and Lion's Mane article covers that specific pathway.

The Bottom Line

Lion's Mane supports synaptic plasticity through two parallel compound pathways: hericerin derivatives from fruiting bodies act through a pan-neurotrophic pathway converging on ERK1/2 signaling, driving extensive neurite outgrowth and branching in hippocampal neurons; erinacines from mycelium activate the BDNF/PI3K/Akt/GSK-3beta cascade through direct blood-brain barrier access. Both pathways converge on CREB activation, which drives the gene expression changes needed for long-term potentiation. Structural evidence includes documented neurite outgrowth in cultured neuronal cells. A 2025 double-blind RCT showed acute Stroop task improvement at one hour, pointing to fast synaptic modulation alongside the slower neurotrophic timeline. A 2026 hypothesis paper proposes non-coding RNA networks as an additional epigenetic mechanism for lasting synaptic changes.

Frequently Asked Questions

What is synaptic plasticity?

Synaptic plasticity is the ability of the connections between neurons (synapses) to change their strength in response to activity. Synapses that fire repeatedly become stronger through a process called long-term potentiation. New synapses can also form when neurons grow new extensions (neurites) and make contact with neighboring cells. Synaptic plasticity is the cellular basis of learning and memory: every time you learn something, synaptic connections in your brain physically change.

How does lion's mane affect synapses?

Lion's Mane affects synapses through two pathways. Hericerin derivatives (from fruiting bodies) act through a pan-neurotrophic pathway that converges on ERK1/2 signaling and drives neurite outgrowth and branching; neurites are where new synaptic contacts form. Erinacines (from mycelium) activate the BDNF pathway through PI3K/Akt/GSK-3beta signaling, which supports synaptic maintenance and strengthening. Both pathways converge on CREB, the transcription factor required for long-term potentiation.

Can lion's mane increase synapse density?

Preclinical evidence supports this. Extensive neurite outgrowth and branching from hericerin derivatives (Martínez-Mármol et al., 2023) and documented neurite outgrowth in cultured cells (Lai et al., 2013) are the structural prerequisites for new synapse formation. When neurons grow longer, more branched processes, they make more synaptic contacts. The Spangenberg 2025 systematic review explicitly links Lion's Mane's erinacine compounds to CREB activation, which drives the gene expression changes that consolidate new synaptic connections into long-term memory traces. Human synapse density data does not yet exist.

Does lion's mane improve memory through synaptic changes?

The mechanistic evidence connects Lion's Mane to the cellular pathway of memory formation: neurotrophin activation, ERK1/2 signaling, CREB phosphorylation, and long-term potentiation are the biological steps underlying memory consolidation. Human functional evidence comes from Mori 2009 (cognitive improvements in a 30-person MCI RCT over 16 weeks)^[12] and Surendran 2025 (Stroop task improvement at 1 hour in healthy young adults). The mechanistic chain from compound to memory is coherent but the human evidence is still from small trials.

What compounds in lion's mane affect synaptic plasticity?

Two main compound classes work through different routes. Hericenones (found primarily in fruiting bodies) stimulate neurotrophins such as NGF and activate ERK1/2 signaling; hericerin derivatives act through a pan-neurotrophic pathway that drives extensive neurite outgrowth and branching, converging on ERK1/2. Erinacines (found primarily in mycelium) cross the blood-brain barrier directly and activate the BDNF/PI3K/Akt signaling cascade. Fruiting body and mycelium extracts therefore produce complementary neuroplasticity effects through distinct molecular pathways.

Does lion's mane increase neurite outgrowth?

Yes, in vitro. Lai and colleagues (2013) documented that Lion's Mane aqueous extract promoted neurite outgrowth in cultured NG108-15 neuronal cells. Martínez-Mármol and colleagues (2023) found that hericerin derivatives drove extensive axon outgrowth and neurite branching in hippocampal neurons, even without serum, through a pan-neurotrophic pathway converging on ERK1/2. Mori and colleagues (2008) established that Lion's Mane compounds stimulate NGF synthesis in 1321N1 human astrocytoma cells, and NGF is a primary driver of neurite outgrowth. This evidence is from cell culture and animal models; neurite outgrowth has not been measured directly in living humans.

Sources & References

1. 1. Source details for this reference are not yet available.
2. 2RTHM-00295·Lai, Puei-Lene et al. (2013). “Neurotrophic properties of the Lion's mane medicinal mushroom, Hericium erinaceus (Higher Basidiomycetes) from Malaysia..” International journal of medicinal mushrooms.Study breakdown →PubMed →↩
3. 3RTHM-00505·Chiu, Chun-Hung et al. (2018). “Erinacine A-Enriched Hericium erinaceus Mycelium Produces Antidepressant-Like Effects through Modulating BDNF/PI3K/Akt/GSK-3β Signaling in Mice..” International journal of molecular sciences.Study breakdown →PubMed →↩
4. 4. Source details for this reference are not yet available.
5. 5. Source details for this reference are not yet available.
6. 6. Source details for this reference are not yet available.
7. 7. Source details for this reference are not yet available.
8. 8RTHM-00921·Contato, Alex Graça et al. (2025). “Lion's Mane Mushroom (Hericium erinaceus): A Neuroprotective Fungus with Antioxidant, Anti-Inflammatory, and Antimicrobial Potential-A Narrative Review..” Nutrients.Study breakdown →PubMed →↩
9. 9. Source details for this reference are not yet available.
10. 10RTHM-00952·Surendran, Geyan et al. (2025). “Acute effects of a standardised extract of Hericium erinaceus (Lion's Mane mushroom) on cognition and mood in healthy younger adults: a double-blind randomised placebo-controlled study..” Frontiers in nutrition.Study breakdown →PubMed →↩
11. 11. Source details for this reference are not yet available.
12. 12RTHM-00165·Mori, Koichiro et al. (2009). “Improving effects of the mushroom Yamabushitake (Hericium erinaceus) on mild cognitive impairment: a double-blind placebo-controlled clinical trial..” Phytotherapy research : PTR.Study breakdown →PubMed →↩