Fungi Were Sending Electrical Signals Before Neurons Existed

Key Takeaways

• Mushroom networks fire voltage spikes that travel consistently in one direction.
• Scrambling the timing destroys the pattern, proving it’s biological, not noise.
• The same signalling logic that brains rely on may be over a billion years old.

A neuron fires in milliseconds. A fungal thread takes three minutes to pass the same kind of message across two centimeters of wood shavings. The difference in speed is staggering, roughly 40 million-fold. But the underlying principle is the same: an electrical signal starts at one point and travels, directionally, to another. If that sounds like a coincidence, consider the timeline. Fungi and animals share a common ancestor that lived over a billion years ago, long before anything resembling a brain existed. The question isn’t whether neurons are impressive. They are. The question is whether they invented directional electrical signalling, or inherited it.

A new study by Andrew Adamatzky, a researcher at UWE Bristol, published in Scientific Reports, offers evidence for the inheritance theory. Adamatzky spent fifteen days recording the electrical activity of oyster mushrooms, Pleurotus ostreatus, the common edible variety you’d find in a grocery store. What he discovered is that fungi electrical signals don’t just flicker randomly. They propagate through the fungal network in one consistent direction, at a measurable speed, with a structure that disappears when you scramble the biological timing.

Fungi now join plants and slime molds in a growing catalogue of brainless organisms that can send electrical messages across their bodies. And because fungi split from the animal lineage so long ago, the capacity for this kind of signalling may be something life figured out well before it figured out nerves.

Adamatzky describes the mycelium as “a spatially extended excitable medium in which electrical signals propagate as ionic waves.”

The speed is telling. At 40 centimeters per hour, fungal propagation sits in the same range as ionic and calcium waves in plants and slime molds. All of these are incomparably slower than nerve conduction. But they share the same functional architecture: a signal that starts somewhere, moves directionally, and arrives somewhere else with a predictable delay. “Information is not encoded in fast all-or-none impulses but in the timing, duration, and spatial progression of slow electrical events.” writes Adamatzky.

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