Bioelectricity, Medicine, and Investment Outcomes

Before humors or elements, Egyptian physicians kept case files. The Edwin Smith Papyrus catalogues 48 trauma cases — mostly head and spine injuries — each with an examination, a diagnosis, and a blunt prognosis: "an ailment I will treat," "I will contend with," or "an ailment not to be treated."

It is startlingly clinical for its age — closer to a modern trauma-surgery textbook than to a book of spells, though magical remedies coexisted for internal illness elsewhere in the Egyptian corpus.

The Edwin Smith Papyrus — case-by-case surgical treatise, c. 1600 BCE.

The Huangdi Neijing, framed as a dialogue between the mythical Yellow Emperor and his physician, proposes that qi — vital energy — flows through the body along channels called meridians, balanced between complementary forces (yin and yang). Illness is a blockage or imbalance in that flow; acupuncture and moxibustion aim to restore it.

Whatever one makes of qi as physiology, the underlying intuition — that health depends on a continuously flowing internal signal reaching every part of the body — is strikingly close to the bioelectric picture this talk builds toward.

Hippocrates broke with the idea that illness was punishment from the gods. He argued disease arises from natural causes — diet, environment, the body's internal state — and should be studied by careful observation at the bedside, not divination. This clinical habit, plus the ethical code that carries his name, is why he's remembered as the "Father of Medicine."

A Renaissance-era marble bust identified as Hippocrates.

Scholars preserved and rigorously extended Greek medicine. Al-Razi (Rhazes) distinguished smallpox from measles by careful clinical comparison and insisted therapies be tested before use. Ibn Sina (Avicenna)'s Canon of Medicine systematized diagnosis, pharmacology, and contagion theory into a single reference — used in European universities for over 600 years.

This is also where alchemy (al-kimia) itself is formalized as a discipline — the direct ancestor of the European alchemical tradition this talk is about to follow into medicine.

Full-body nerve map from Mansur's Anatomy — the Persian/Islamic anatomical tradition, c. 1390.

For Bacon, alchemy was not only about metals — it was a medicine of restoration. The ideal body was one where the four elements were brought into equal proportion: the corpus equale, "the equal / balanced body," less subject to corruption, disorder, and decay.

Michael Maier, Symbola aureae mensae, 1617 — Bacon balancing fire and water.

When plague killed a third of Europe, physicians reached for the tools they had: bloodletting to rebalance humors, "miasma" (bad air) avoidance, purging, and aromatic herbs against foul-smelling air (the iconic beaked plague-doctor mask came later, in 17th-century outbreaks). None of it addressed the actual cause — a bacterium spread by fleas — and mortality was essentially unaffected by treatment.

The plague didn't discredit humoral theory outright — but it quietly built the pressure that, two centuries later, made room for Paracelsus's more targeted, chemical alternative.

A "Dance of Death" manuscript illustration — Death confronts a knight, c. 15th century.

While Bacon and Paracelsus reasoned about the body through elements and chemistry, Leonardo reasoned through direct observation. His contribution was less a single discovery than a method: observe the body directly, draw it from multiple viewpoints, and explain structure as function. The Vitruvian Man is the clearest statement of it — the body as a system of exact, recoverable proportion, not myth.

That instinct — that form itself carries lawful, measurable structure — is the same one D'Arcy Thompson will formalize mathematically four centuries later, and that this talk keeps returning to.

Leonardo da Vinci, Vitruvian Man, c. 1490 — the body as proportion, not myth.

Leonardo turned drawing into a research tool. Working from direct dissection — knowledge from bodies, not only books — he showed the body in layers (bones, muscles, tendons, step-by-step) and from multiple views: section, elevation, and "exploded" arrangements.

These conventions now feel natural in medical illustration — one reason his drawings still look modern. Making the body legible in three dimensions is the precondition for asking what makes it work.

Leonardo was strongest when a drawing explained how the body works, not just how it looks. He described the heart's chambers and valves with notable accuracy and grasped it as a one-way pump; his fetal studies made gestation visually concrete — while still mixing human observation with animal evidence.

Because the notebooks stayed unpublished until the late 1800s, their immediate medical impact was limited — but their visual logic anticipated modern anatomical illustration, and the heart-as-pump instinct points straight at Harvey.

Paracelsus moved healing from general balance toward targeted remedies — substances, doses, thresholds. He still belonged to a magical and theological world, but he pushed medicine toward chemical intervention: not only rebalancing humors, but attacking a disease directly.

His framing matters for what follows: bioelectricity also deals in thresholds — too much, too little, wrong place, wrong timing — and cells behave differently depending on where they land.

Portrait of Paracelsus — physician-alchemist, sword marked "AZOTH."

Paracelsus's most durable idea: nothing is simply "medicine" or "poison." The same substance heals at one dose and harms at another. Effect depends on amount — a threshold, a window, a curve — which is why he is often called the father of toxicology.

It is a fundamentally quantitative way to think about the body: not what a thing is, but how much, where, and when. Bioelectricity obeys the same logic — the right voltage in the right place regenerates; the wrong level does nothing, or drives cancer.

The therapeutic window — the same substance moving from too little, to remedy, to poison.

For 1,300 years, anatomy was taught from Galen's texts — largely based on animal dissection, since human dissection was rare. Vesalius dissected human cadavers himself and found hundreds of discrepancies. De Humani Corporis Fabrica corrected the map of the body from direct observation, not inherited authority.

It's a small methodological shift with huge consequences: once anatomy is settled by looking, not citing, every subsequent physiological claim — including electrical ones — has to earn its place by the same standard.

De Humani Corporis Fabrica, 1543 — an opened thoracic cavity, drawn from direct dissection.

Galen taught that blood was continuously produced by the liver and consumed by the tissues. Harvey calculated that the heart pumps far more blood per hour than the body could possibly make — so it had to be the same blood, recirculating through a closed loop, driven by the heart as a mechanical pump. He proved it with ligature experiments on living arms — described in careful prose, building on his teacher Fabricius's discovery of the venous valves.

A quantitative argument — flow rate, not philosophy — settles a 1,400-year-old question. That's the exact move bioelectricity researchers make next: measure the signal, don't just theorize it.

Forearm ligature experiment demonstrating one-way venous valves — Harvey's argument in De Motu Cordis, 1628 (illustration from a later edition).

Descartes helped shift natural philosophy away from hidden qualities and purposes. He argued the nature of matter "consists ... simply in its being extended in length, breadth and depth" — body as extension, change as motion, governed by laws that could be studied systematically.

Principles of Philosophy, Part II, §4; laws of nature developed at §§36–37. Nature becomes a lawful physical system — something that can be modeled, measured, and explained mechanically.

Descartes's system of vortices, Principia Philosophiae, 1644 — the universe explained through moving matter, not Aristotelian purpose.

Descartes did not draw the first anatomical nerve map — Galen and Vesalius had already described and illustrated nerves. What he did was newer: he imagined nerves as hollow tubes carrying "animal spirits," with the heart as a spring and the brain's cavities as outlets — the body as a physical communication system.

Treatise on Man. The mechanism was wrong — no fluid runs through the nerves — but the move was profound: signalling as plumbing, not soul. Swap "fluid pressure" for "electrical potential" and this is nearly the right question, asked 150 years before anyone could test it.

Descartes's nervous system as hydraulic machinery — brain, nerves, and pineal gland routing "animal spirits," De Homine, 1662.

Heat near the foot pulls a tiny thread, opens a pore in the brain, and sends animal spirits into the muscles that withdraw the foot — all before conscious reasoning gets involved. Descartes gave one of the first mechanical accounts of what we now call reflex action.

Treatise on Man. The body is not a passive container for the soul — it has automatic mechanisms of sensation, pain, and defence. The Becker Medical Library describes the Treatise of Man as the first European textbook on physiology, containing a statement resembling the modern concept of reflex action.

Descartes, Traité de l'homme, 1664 — the chain students can read at a glance: fire → skin/nerve → brain → animal spirits → muscle.

Mesmer claimed an invisible bodily fluid — animal magnetism — whose blockage caused disease and whose redirection cured it. Paris salons filled with patients gripping iron rods around his magnetized baquet. Patients convulsed, wept — and often improved.

In 1784 a royal commission — Benjamin Franklin, Lavoisier, Guillotin — ran what is arguably history's first blinded, placebo-controlled trial: blindfolded patients responded to where they believed the magnetism was, not where it was. The fluid didn't exist; the healing was imagination.

A mesmerist at work. Wellcome Collection, public domain.

This is the pivot. For two thousand years, the force animating the body was philosophical — humors, elements, proportion. Galvani's twitching frog leg made it measurable: an experimental electrical phenomenon, not a hidden vital force.

Plate from Galvani's De viribus electricitatis in motu musculari, 1791.

Galvani's nephew took the frog-leg result on tour. In London, 1803, Aldini applied a voltaic pile to the corpse of the executed murderer George Forster: the jaw clenched, an eye opened, a fist rose. Newspapers asked whether the dead could be revived.

Fifteen years later Mary Shelley — who knew these demonstrations from the scientific gossip of her circle — published Frankenstein. The idea that electricity is the animating principle of life entered popular culture a century before anyone could measure a membrane potential.

Plate from Aldini's Essai… sur le galvanisme, 1804. Wellcome Collection.

ProbKnow is a probabilistic knowledge graph for bioelectricity research — papers, researchers, organizations and concepts, all linked by inferred relationships.

• Surfaces hidden connections between labs, papers and ideas the citation graph misses.
• Lets a non-expert ask "who works on planarian regeneration AND uses GEVIs?" and get a navigable answer.
• Updates as new papers land, so the map stays current as the field accelerates.

Try it live → probknow.com

ProbKnow knowledge graph · live exploration of the bioelectricity literature.

In On Growth and Form, Thompson showed you could turn one species' body into another's by warping a coordinate grid — not by changing the parts list.

That image is a conceptual precursor to bioelectricity research a century later: there is some field, some tissue-scale instruction, that helps decide shape on top of the cellular hardware.

In 1952, less than two years before his death, Turing showed that two diffusing chemicals with the right nonlinear interaction can spontaneously break a uniform tissue into stable spatial patterns — spots, stripes, waves. From nothing but the math.

• Activator + inhibitor diffusing at different rates — the activator self-amplifies locally, the inhibitor diffuses faster and suppresses neighbours. A uniform field becomes a regular pattern.
• Predicted patterns ~25–40 years before any biological mechanism was confirmed.
• Vindicated in marine angelfish stripes (Kondo & Asai, Nature 1995), mouse digit spacing (Sheth et al., Science 2012), hair-follicle spacing (Sick et al., Science 2006), and fish skin pigmentation.

Gray-Scott reaction-diffusion simulation (activator V × inhibitor U, du=0.2 / dv=0.1, f=0.055 / k=0.062) — a noisy central seed self-organizes into Turing spots. Rendered from fractastical/morpholib · 1952-turing-morpho.py.

Raup parameterised gastropod shells with just three numbers — W (whorl expansion rate), D (distance from the coiling axis), and T (translation rate along the axis). Sweep the parameters and you generate the full theoretical morphospace of coiled shells.

The striking finding: sampled gastropod shells occupy only a small region of that space. Most of the cube is geometrically possible but biologically unused.

Using voltage-sensitive dye, the Levin lab imaged the surface of Xenopus embryos as the head developed. Hyper- and depolarized regions pre-figured the eyes, mouth, and nostrils — sometimes hours before the cells got there.

Disrupt the voltage pre-pattern and you get craniofacial mispatterning (colloquially the "Picasso tadpole" phenotype) — features in the wrong places.

Cut a planarian flatworm in half and it normally regenerates one head and one tail. Briefly perturb its bioelectric circuit before cutting and it can grow two heads instead — and in Durant et al. (2017) that the altered head/tail target morphology is maintained across subsequent re-amputations via stable gap-junctional state changes, even though the genome was never touched.

• Body shape is partly stored in tissue-level voltage gradients (V_mem)
• That store is rewritable and the rewrite can persist across regeneration
• It behaves like pattern memory: long-term, addressable, content-specific

Gordon Marsh and H.W. Beams cut planaria into fragments and let them regenerate inside a DC electric field. Weak fields: normal worms. Stronger opposing fields: two-headed worms. Strongest: the body plan fully reversed — a head where the tail should be.

The anterior–posterior axis — the most basic decision a body makes — obeyed an imposed voltage gradient, overriding whatever the tissue "remembered." Follow-up work showed the field itself, not current density, carried the signal. Then the result sat largely forgotten for half a century.

The two-headed phenotype — first induced electrically in 1952, reproduced bioelectrically by the Levin Lab decades later.

Take embryonic skin cells from Xenopus laevis, remove the rest of the embryo, let the cells reaggregate. They do not become frog skin.

They self-organise into a novel anatomy: 2020 — first xenobots, designed by an evolutionary algorithm and assembled by hand (Kriegman et al., PNAS). 2021 — ciliated, self-propelling forms (Blackiston et al., Sci. Robotics) and kinematic self-replication, where xenobots gather loose cells into new xenobots (Kriegman et al., PNAS).

Xenobot navigating a field of loose cells. Source: M. Levin / Allen Discovery Center, Tufts.

Made from adult human tracheal cells, anthrobots aggregate into "super-bot" clusters. In in vitro assays they move across cultured human neurons, congregate near injuries, and are associated with improved closure in neuronal-wound assays.

Because they're built from the same cells as the tissue around them, they natively share its bioelectric and biochemical signalling — making them candidate research tools for studying repair and tissue dynamics.

Super-bot cluster (green) on cultured human neurons (red), next to a neural wound. Source: Gumuskaya et al. (2024), Levin lab.

Break an epithelium and the tissue's battery short-circuits: a steady wound current flows, pointing at the injury. Min Zhao's lab showed cells read this field and migrate along it (galvanotaxis) — and his 2006 Nature paper found the field can override every other guidance cue, steering through PI3K/PTEN, the same machinery cancer mutates.

This is the most investable corner of bioelectricity today: the signal is measurable, the mechanism is molecular, and applied fields already accelerate closure in cornea and skin models — a direct path to wound-care devices for diabetic ulcers and surgical healing.

→ full interactive course: "Electric Fields That Heal"

Cortical actin waves (green, LimE) lock to the cathode-facing edge — cells steer by reading the wound field. Weiner et al., eLife 11:e73198 (2022) · CC-BY 4.0.

Min Zhao, M.D., Ph.D. — UC Davis. Zhao et al., Nature 442, 457–460 (2006).

Pharma's first scalable business model looked like consumer packaged goods, not laboratory R&D: common complaints, cash purchase, memorable brands, enormous advertising reach. Tonics, laxatives, "blood purifiers" — proprietary through brand, secrecy and distribution, not molecular patents.

Brand and distribution came before modern clinical proof.

Peruna almanac cover — manufacturers printed advertising almanacs from the 1840s on. (DPLA, public domain)

If voltage maps can navigate cells through the space of possible bodies, where does that space live? Levin's working answer: a structured, non-physical space of forms, patterns and higher agencies that biological systems (and minds, and AI) appear to discover, not invent.

Full glossary & symposium slides → /platonic-space

V_mem wave propagating across a tissue grid · inspired by BETSE bioelectric simulations (Pietak & Levin 2016).