How Rat Processing Unit works
A lab of 7,126 real neurons, each recorded from a real rat’s brain. Anyone can explore them for free. Anyone can also rent a neuron by the day: name it, record its experiments in the shared, simulated rat cortex, and take its sound and data with them. Rentals, names and results live on Robinhood Chain, a public blockchain, so anyone can re-run every result and check it.
Plain about what is real. The neurons are real recordings. The brain anatomy is a real MRI scan. The cortex is a simplified simulation of a published computer model, not a living brain, and the 3D rat body is an illustration.
What’s real
Everything below comes from real rats and real measurements, exactly as published in Scientific Data.
neurons recorded from the neocortex of 20 rats, under anesthesia
each neuron’s average spike, kept permanently in a public record
each neuron’s full recording, spike for spike, locked by fingerprint
the 3D brain, traced from an MRI scan of a real adult rat
The neurons
The recordings come from a published dataset: 128-channel silicon probes placed in the neocortex of 20 rats under ketamine/xylazine anesthesia. The researchers sorted the signals into 7,126 single units, which are individual neurons as best as spike sorting can tell. That count is the supply.
Each neuron carries its real measurements:
- Spike shape: the neuron’s average spike, 81 samples at 20 kHz (about 4 ms). Stored permanently in the public record (on-chain) once neurons are assigned.
- Firing record: every spike it fired during its recording session, at the original 1/20,000 s precision. Hosted off-chain and locked by fingerprint.
- Traits: firing rate, burst index, spike width (narrow or broad), amplitude, cortical area, estimated layer, and the rat it came from.
Rarity comes from these measurements, shown as percentiles across all 7,126 neurons. Nothing is generated or invented. Two caveats: the layer is the researchers’ estimate from the probe position, and “narrow” vs “broad” spike width is our labelling (under or over 0.45 ms).
Traits and rarity
Every trait is derived from the neuron’s real measurements by fixed rules, so anyone can recompute them from the published data. Nothing is random or hand-picked.
| Trait | Values | Rule |
|---|---|---|
| Firing style | Hyperactive · Burster · Busy · Steady · Quiet | Firing-rate rank: top 3% Hyperactive, top 30% Busy, bottom 10% Quiet. Burst-index top 10% is Burster. |
| Voice | Thunder · Loud · Clear · Soft · Whisper | Spike amplitude rank: top 3%, top 15%, top 50%, bottom 50%, bottom 15%. |
| Spike shape | Inverted · Narrow · Broad | Inverted if the spike’s main peak points up (flagged in the dataset); otherwise narrow or broad by width (0.45 ms). |
| Probe depth | 1 · 2 · 3 | Which of the probe’s recording depths the neuron was found at. |
| Area, layer, rat | as recorded | From the dataset; the layer is the researchers’ estimate. |
| Title | e.g. Fastest neuron, Loudest in M1 | 1-of-1: the record holder overall, or within its cortical area. |
Rarity score adds up how surprising each of its traits is (−log₂ of how common it is), plus a bonus for titles. Neurons are then ranked from #1 (rarest) to #7,126; every rank is unique. Tiers follow the rank: Legendary (top 1%), Epic (top 5%), Rare (top 20%), Uncommon (top 50%), Common.
Renting
Every one of the 7,126 neurons can be rented, one renter at a time, for 2 to 30 days ahead (2 days at minimum). Renters can extend their own rental; nobody can take a neuron while someone else rents it.
- Price is per day and depends on the neuron’s tier (Common to Legendary, plus the 1-of-1 title holders). It is set in ETH and in $RPU; paying in $RPU costs less.
- Discounts: longer rentals cost less per day, and holding $RPU gives an extra discount. All discounts together are capped at 45%.
- While you rent a neuron you can name it, record its results in the cortex (for a small fee), and download its spike train, sound, ringtone and specimen card.
- All payments go to the lab treasury. The treasury address is public on-chain, and any change to it is public too.
Title auctions
The 1-of-1 title neurons (such as “Fastest neuron”) are rented only by auction:
- Anyone can start an auction for a title neuron once its current rental will be over by the time the auction ends. Auctions run 3 days; the winner rents the neuron for 7 days.
- Each bid must beat the last by at least 5%. A bid in the last 10 minutes adds 10 minutes, so nobody can snipe it at the final second.
- If you are outbid, you get your whole bid back: withdraw it from My Lab whenever you like.
- Anyone can settle a finished auction. The winner’s rental starts then, and the winning bid goes straight to the lab treasury.
- Each auction keeps the rules it started with, even if the rules for future auctions change.
Waitlists
For any neuron someone else is renting, you can join a line of up to 10 people. When the rental ends, the first person has one day to rent it, then the next, and so on; after everyone’s turn it is open to all. Once $RPU exists, the waitlist is for $RPU holders. A new rental clears the line.
Selling, giving and swapping rentals
A rental can be passed on before it ends. The end date never changes; only who holds it.
- Sell the rest of your rental at a price you choose. When it sells, you receive 95% (withdraw it from My Lab) and 5% goes to the lab treasury. The fee can never exceed 10%.
- Give it to any wallet for free.
- Swap: offer your rental for one someone else is renting. If they accept, you trade rentals, and each neuron keeps its own end date.
- A listing or swap offer is tied to the exact rental it was made for. If that rental ends, or you extend it, the listing or offer stops counting, so an old price can never come back to life.
- The neuron’s name resets for its new renter. Trades earn no Lab points, which come only from payments to the lab.
Owning a neuron outright
When buyouts are open, any neuron that nobody owns can be bought outright. You receive it as an NFT whose token number is the neuron’s number.
- Price: the neuron’s daily rent times 365, in ETH or $RPU. The payment goes to the lab treasury.
- As its owner you can rent it for free at any time (free rentals earn no Lab points), and you receive a share of the rent others pay for it: 80% to start, which the team can set between 50% and 95% for future rentals. Your share waits in the lab until you withdraw it from My Lab.
- You can’t buy a neuron someone else is renting until their rental ends, and title neurons stay auction-only.
- Someone else’s owned neuron can’t be rented with Lab points, only with ETH or $RPU, so its owner is always paid.
- Only a limited number of neurons can be owned (500 to start), so most stay open to everyone.
- Earnings depend entirely on how often others rent your neuron. There is no guaranteed income, and past rentals don’t predict future ones.
Lab points
Points reward using the lab. They are earned only from real payments and spent only on free rental days.
- Earn: about 3 points per $1 of rent, and 1 point for each result you pay to record. Free days paid with points earn nothing.
- Spend: points pay for free rental days (roughly 1 point = $0.01 of rent).
- Seasons: points reset every 13 weeks.
- Guardrails, enforced by the contract: the points a paid day earns can be worth at most 10% of a day’s rent, so rewards can never outgrow the payments behind them; only the linked cortex can award recording points, and that link can be set only once.
- Points have no cash value and can’t be sold or transferred. Rates may change with notice; points already earned are never taken away.
Names
Renters can name the neurons they rent, and anyone can set a public collector name. Names may use any letters, emoji, other alphabets and symbols.
- 1 to 24 visible characters (an emoji counts as one).
- No hidden, control or text-direction characters; no leading, trailing or double spaces.
- Unique: capitals, accents, styled letters, lookalike letters from other alphabets, spaces and
. - _ 'are ignored when comparing, so “Barrel Boss”, “BARREL-BOSS” and a lookalike “Bаrrel Boss” count as the same name. - A neuron’s name lasts while its renter rents it. When the rental ends the name is freed.
- A name checker applies these rules and signs a one-time approval; the contract also refuses any duplicate itself. The team can clear an abusive name but can never set or change anyone’s name.
The shared cortex
The cortex is the Blue Brain Project’s model of rat somatosensory cortex: 5,924 neurons across six layers and 568,717 synapses, built by EPFL from real measurements (at 7% of real neuron density). We run a simplified version in your browser:
- leaky integrate-and-fire neurons, with connection strengths and delays taken from the model’s synapses;
- a simple short-term depression rule, so activity stays bounded;
- integer arithmetic only, so every computer gets exactly the same result.
When you fire, each of your neurons drives 24 model cells in its estimated layer. The busiest stretch of its real recording is replayed, spike for spike, as input. This mapping is our design choice, not biology. The site draws the model’s response layer by layer.
Holder features
- Name your neuron. Owners can give their neuron a name of 1–24 letters, digits, spaces, dashes, apostrophes or dots. Names are unique (ignoring letter case), stored on-chain, and stay with the neuron when it is sold; the new owner can rename it. The project can remove an abusive name but can never set one.
- My Lab. Your neurons, saved experiments, your recorded results (each with Verify) and your collector name, in one place.
- Saved experiments. Save any combination of neurons and replay length, and share it as a link; opening the link loads the same experiment. Saved experiments live in your browser.
- Download your neuron. Its real spike train (CSV), its sound (WAV), a 30-second ringtone and a printable specimen card.
- Collector name. A public name shown next to your neurons (“Collected by …”) and your recorded results, stored on-chain. Unique, and only you can set yours.
- Early access to new brains. When a new cortex version is added, holders use it first on the site for a week. Everyone else keeps firing the previous version until then. Every recorded fire notes which brain version it used, so old results always verify against the brain they ran on.
Verify it yourself
Every recorded fire stores two fingerprints: an input digest (which brain, which neurons, how long) and a result digest (every spike the model produced). The brain files are locked by their own fingerprint on the cortex contract.
In the browser
Under “Recently recorded” (or in My Lab → History), press Verify. Your browser downloads the brain, checks its fingerprint, re-runs the fire, and compares both digests with the on-chain record.
From the command line
# 1. get the public files (brain + neurons) from the project's data host
# 2. with Node.js 20+ in that folder:
node fire.mjs <neuron> [<neuron> …] <milliseconds>
# prints inputDigest and rasterDigest: compare with getFire(id) on the cortex contractRecorded results list the neuron numbers they used, so anyone can re-run them. The brain fingerprint rule is sha256(sha256(cells.bin) ‖ sha256(conn.bin) ‖ sha256(params.json)).
The contract cannot check a simulation. It only stores what was submitted. That is why results are reproducible: if a record doesn’t reproduce, anyone can show it, and it can be flagged (never deleted).
The public record
“On-chain” means stored permanently on Robinhood Chain, where anyone can read it and nobody can change it.
| In the public record (on-chain) | Hosted, locked by fingerprint |
|---|---|
| Who rents which neuron and until when, names, and every recorded result | Firing records (about 100 MB in total) |
| Every neuron’s tier, used for its price (written once from the data, then frozen) | The cortex model files |
| Prices, discounts and the treasury address | Neuron traits and spike shapes (units.json, waveforms.bin) |
| Brain fingerprints and every fire’s digests | The 3D atlas meshes shown on the site |
For developers and AI agents
Anyone can use the lab from code, with no account and no key. Everything is deterministic, so any result can be re-run here and checked. Please credit the data when you publish results: “Data: Horváth et al. 2021 (CC-BY) via ratprocessingunit.com”.
As tools for AI assistants (MCP). Add https://ratprocessingunit.com/mcp as a remote MCP server (in Claude: Settings → Connectors → Add custom connector). Tools: fire_neurons, get_neuron, neuron_of_the_day, top_results, about_the_lab.
HTTP API (full description in openapi.json, a plain summary in llms.txt):
| Endpoint | What it does |
|---|---|
/api/fire?neurons=6107,3409&ms=300 | Fire 1–16 real neurons for 50–1,000 ms. Returns model spikes, spikes per layer, first spike time, fingerprints, and credit for rented neurons. |
/api/neuron/6107 | A neuron’s real traits and links. |
/api/neuron/6107/music | Its whole recording as one minute of music (WAV). |
/api/neuron-of-the-day | Today’s featured neuron, the same one the site features. |
/api/top | This week’s biggest recorded results that re-run identically. |
Limits: 20 fires and 60 lookups per minute per caller. If paid access is switched on, callers beyond the free limit receive an HTTP 402 Payment Required response in the x402 format and can pay per call in USDC on Base.
Contracts
On Robinhood Chain. Their addresses are listed under Links once they are live.
- RPULab: renting, prices and discounts, and names. Payments go straight to the treasury, except owners’ shares of rent, which it holds only until each owner withdraws them.
- RPURentalMarket: selling, giving and swapping the rest of a rental. It holds only sellers’ unwithdrawn proceeds, and is the only contract allowed to move a rental to a new renter.
- RPUNeuronDeeds: owned neurons as NFTs (token number = neuron number), with royalties capped at 10%. Buyout payments go straight to the treasury.
- RPUTitleAuctions: weekly auctions for the title neurons. It holds only the current top bids and refunds owed, and pays winning bids to the treasury.
- RPULabCortex: brain versions (append-only; a fix adds a new version and old records keep theirs) and recorded results. Only a neuron’s current renter can record with it.
The contracts are covered by 119 automated tests, including invariant tests that run over a hundred thousand random actions and check that every payment reaches the treasury exactly and no rental ever runs more than 30 days ahead.
What the team can and can’t do
Straight from the contracts. Anyone can check these on the block explorer.
| The team can | The team can never |
|---|---|
| Set daily prices and discounts | Change the price of a rental already paid for, or give total discounts above 45% |
| Pause new rentals | End, shorten or take over anyone’s rental. Pausing never touches existing rentals |
| Change the treasury address (publicly, on-chain) | Take money from the contract: it holds only owners’ unwithdrawn earnings, which only each owner can withdraw |
| Set points rates | Make a paid day earn points worth more than 10% of its rent, or award points directly: the cortex that may award them is linked once, for good |
| Write each neuron’s tier from the data, then freeze it | Change tiers after the one-way freeze |
| Set the recording fee | Set it above 0.01 ETH, or above one Common day in $RPU |
| Add new brain versions | Change or delete an old brain version or any recorded result (results can only be flagged, with a public reason) |
| Clear an abusive neuron or collector name | Set or change anyone’s name |
| Set the $RPU token address once, when it exists | Change it afterwards |
| Link the title auction house once, and set rules for future auctions | Change a running auction’s rules, pick a winner, keep bids (outbid bids are always refundable), or re-link the lab to another auction house |
| Open or close buyouts, raise the number of neurons that can be owned, set the buyout length (90 to 730 days of rent) and the owners’ share (50% to 95%) for the future | Take back a neuron someone owns, lower the limit below what is already owned, touch owners’ earnings, or change a share already earned |
| Link the rental market once, and set its fee on sales | Set the fee above 10%, touch sellers’ proceeds, move anyone’s rental, or link a different market later |
| Nothing about waitlists beyond pausing new rentals | Reorder a waitlist, skip someone’s turn, or rent a neuron during someone else’s turn |
Renting gives no share of the treasury, fees or profits.
Data and credits
The lab stands on three openly licensed works. Please credit them when you publish results: “Data: Horváth et al. 2021 (CC-BY) via ratprocessingunit.com”.
Recordings CC-BY
Horváth C, Tóth LF, Ulbert I, Fiáth R (2021). Dataset of cortical activity recorded with high spatial resolution from anesthetized rats. Scientific Data 8:180.
Cortex model CC BY 4.0
Pokorny C. (2024). SSCx toy circuit with 6k neurons in SONATA format. Blue Brain Project, EPFL. doi:10.5281/zenodo.12202781.
Brain anatomy CC BY 4.0
Waxholm Space atlas of the Sprague Dawley rat brain v4 (Papp et al. 2014, NeuroImage 97; Kleven et al. 2023). Surface meshes from MeshView, Neural Systems Laboratory, University of Oslo.
Rat Processing Unit is not affiliated with or endorsed by these researchers, EPFL, the University of Oslo, Robinhood or Amazon.
Links
Contracts on Robinhood Chain
- Addresses appear here at launch.
FAQ
Is this real?
Yes. Every one of the 7,126 neurons was recorded from a real rat’s brain by neuroscientists, and its spike shape and firing record are exactly what they measured. The brain you explore is traced from an MRI scan of a real rat, and the cortex you fire them into runs a simplified version of the Blue Brain Project’s model, which was built from real measurements. Read the original studies: the recordings paper and its published dataset, the cortex model, and the brain atlas (Papp et al. 2014, Kleven et al. 2023).
Were rats harmed for this project?
No new experiments were done for this project. The recordings come from a study published in 2021, performed under the EU directive on animal research (2010/63/EU) and approved by the Animal Care Committee of the Research Centre for Natural Sciences and the National Food Chain Safety Office of Hungary. We reuse its openly licensed (CC-BY) data.
Why is $RPU paired with Amazon (AMZN)?
Because Amazon is where rat-neuron AI went mainstream. In September 2026, Amazon Web Services began offering select customers an AI video model built with a layer derived from real rat neurons, made by The Biological Computing Company. Pairing $RPU with AMZN, the tokenized Amazon stock on Robinhood Chain, ties the lab to that moment. Rat Processing Unit is independent: it is not affiliated with, endorsed by or partnered with Amazon.
Can I choose which neuron I rent?
Yes, any neuron that nobody is renting right now. Rarer tiers cost more per day. If someone is renting the one you want, it frees up when their rental ends.
Can I own a neuron outright?
Not yet. Buying a neuron outright (as an NFT) is planned for a later phase, once renting shows which neurons people want.
Why can’t anyone fire my neuron and record it?
Anyone can try firing any neuron on the site. Only its current renter can record a result on-chain.
What is $RPU?
The project’s token on Robinhood Chain, paired with the Amazon stock token (AMZN). Robinhood’s stock tokens are not available in every country; check your eligibility. Nothing here is financial advice.