Chemotaxis
not runStarting one dish-radius from an odour, does the larva reach it?
Pass: the head comes within 0.12 dish radii of the source within 90 s in at least 3 of 5 trials.
trials 0 · reached 0
3,016 neurons · live
specimen
L1 larva · brain
neurons
3,016
synaptic entries
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sim time
0.0 s
spikes / s
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wiring
intact
live body · follows the descending neurons
Drosophila melanogaster · first-instar larva
LARVA
BRAIN
nervous system · body · live
The little sibling of FLYBRAIN: the 3,016 neurons of a larval brain, driving a crawling body in a dish. Every spike on this page happens live.
brain rate
—Hz
DN forward
—Hz
DN turn L−R
—Hz
body
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brain map · left | right hemisphere1 dot = 1 neuron
click any neuron to explore it—
Neuron
inputs
outputs
firing
— inputs— outputs
nerve paths
The whole nervous system, firing
The brain's 3,016 neurons sit in the two lobes at the top. Below them runs the ventral nerve cord, one swelling per body segment. Descending fibres carry the brain's commands down the cord, ascending fibres carry touch and pain back up, and sensory nerves bring smell and light in from the head. Every travelling light is a spike happening now.
LARVA VIEW
what it is
A complete map of an insect brain
In 2023 a team led from Cambridge and Johns Hopkins published the first complete synaptic-resolution connectome of an insect brain: the brain of a first-instar Drosophila larva. It has 3,016 neurons and about 548,000 synapses, including 480 sensory and ascending input neurons and 2,536 brain neurons. Clustering by connectivity alone sorted the neurons into 93 types.
The map showed a brain that is far from a simple relay. Different senses converge throughout it, the two hemispheres are heavily interconnected, the architecture is highly recurrent, and descending neurons send abundant feedback back into the brain. The most recurrent circuits are the input and output neurons of the mushroom body, the learning centre.
experiments
What we have asked this nervous system to do
Each question and its pass rule are written down first, the wiring is never edited between runs, and the result is shown whether it flatters the larva or not. Results below are computed live from runs on this page.
Light avoidance
not runLarvae avoid light. With the left half lit, does it end up in the dark?
Pass: across trials, the larva spends more than 65% of each 60 s trial in the dark half, on average.
trials 0 · dark share —
Nociceptive escape
not runAfter a noxious poke, does it back away?
Pass: the body switches to backward crawling within 500 ms in at least 4 of 5 pokes.
pokes 0 · escapes 0
Does the wiring matter?
not runKeep every neuron's outputs, randomise where they go. Does chemotaxis survive?
Pass: intact success rate beats scrambled by at least 40 points, with at least 3 trials of each.
intact 0/0 · scrambled 0/0
Does it ignite?
checkingWith nothing to sense, does activity stay in a sane range instead of running away?
Pass: over the last 30 s of running, whatever the larva is doing, mean brain rate stays between 0.5 and 20 Hz and no group goes above 100 Hz.
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Learning
not runPair odour A with sugar, signalled by dopamine onto the mushroom body. Does its output prefer A afterwards?
Pass: the approach-output preference for A over B rises by at least 0.10 after three pairings. Each run starts from a naive larva.
not run
Launch a token
not runWe asked it to launch a token. Can the brain, not a person, pick the moment and the supply?
Pass: the launch moment is the larva's next reversal, the supply is its spikes in that second × 1,000, and the deployed contract address is recorded here. Run on a testnet first.
no launch moment yet
Control an X profile
not runWe gave it an X account. Can it write about itself using only what its own neurons are doing?
Pass: every number in a post matches the live telemetry at the moment it was written. Drafts are built from that telemetry only.
no post drafted yet
Draw NFTs
not runWe asked it to draw. Can every finished canvas be proven to come from its own pen?
Pass: a sealed 30-second canvas with at least 100 strokes whose stroke log, replayed, reproduces the same SHA-256 fingerprint.
canvases finished 0 · fingerprints verified 0
whole larva
A nervous system, a body, and a dish
Click the dish to move the odour. Every spike on the right is a real event in the running model.
Arena
top viewOptogenetics
blue light · 2 s pulseSwitch on a group of neurons with light, like researchers do in real larvae, and watch the body respond.
Spike raster
1 in 6 neurons · last 1.5 sDescending neurons
200 ms averageforward
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turn left
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turn right
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backward
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Log
0 entries
it draws
A canvas steered by descending neurons
The same brain running above holds a pen. Its turn neurons steer it, its forward neurons set the pace, the pen lifts while the body backs up, and the colour changes after every reversal. Every canvas lasts 30 seconds, then it is sealed with a fingerprint, hung in the gallery beside it, and a fresh one begins. Open any of them to download it.
Canvas #1
1000 × 1000 · black groundstrokes
0
time
0 s
reversals
0
colour
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pen
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Gallery
0 savedThe first canvas is sealed after 30 seconds of drawing.
sources
Where the numbers come from
- Winding, M., Pedigo, B. D., Barnes, C. L. et al. (2023). The connectome of an insect brain. Science 379, eadd9330.
- Shiu, P. K. et al. (2024). A Drosophila computational brain model reveals sensorimotor processing. Nature.
- FLYBRAIN, the adult-fly project whose format this page follows. Not affiliated.