KBrain Map
Real brain maps, measured.
We read neuroscience from the actual connectome data (human, mouse and fly) and publish our numbers, our methods and our mistakes.
Maps →
The public brain maps we measure from: human cortex (H01), mouse (MICrONS) and fly (FlyWire). What they are and how to open them.
Numbers →
Every number we measured, with the map it came from, how we measured it and what it does not show.
Stories →
Write-ups of each measurement: cells and wiring, drugs and receptors, myths checked, methods and corrections.
Latest stories
How Close Are Neurons to Blood Vessels? We Measured 10,441 of Them in a Real Human Brain Sample
In about one cubic millimetre of human cortex mapped with an electron microscope (H01), 98% of neurons sit within 50 µm of a blood vessel (median 23 µm). How we measured it, why neurons stay so close, and what the number does not tell you.
Is Dopamine the Pleasure Chemical? Not Quite. 390 Fly Neurons, One Receptor, and What the Experiments Say
We counted the predicted dopamine neurons in a complete fruit-fly connectome, looked at dopamine bound to the human D1 receptor, and checked the 'pleasure chemical' label against the monkey and rat experiments behind it. Includes the four things we fixed before publishing.
Why Do Some Allergy Pills Make You Sleepy? Eight Histamine Neurons, One Receptor Pocket, and a Door
We counted the histamine neurons in a complete fruit-fly connectome, overlaid two real antihistamine structures on the human H1 receptor, and followed the evidence for why only some allergy pills make you drowsy. Includes the two counting mistakes we caught before publishing.
Which H01 Is It? Two Public Synapse Releases, Only One Matches the Paper — and How We Found Out the Hard Way
The public H01 human-cortex bucket holds two synapse layers. 20210601 is raw detection output; 20210729 matches the paper's per-cell Table S14 exactly. We used the wrong one in two posts. Here is how to tell them apart.
Human vs Mouse vs Fly: How We Measured Five Rounds of Brain-Cell Comparisons (and What We Got Wrong First)
We compared human, mouse and fruit-fly neurons in five rounds using three public connectomes. This post lists every number, how it was measured, the seven mistakes we caught before publishing, and why the comparison is not a fair fight.
Same Lock, Different Effects: Why LSD Is Psychedelic and Lisuride Isn't
LSD and lisuride occupy the same pocket of the human serotonin 2A receptor, 0.12 Å apart. Only LSD is psychedelic. We compared five published crystal structures residue by residue, checked the LSD pose against an independent structure from another lab, and went through what the literature says explains the difference.
Why Is Nicotine So Hard to Quit? What the Real Receptor Structures Show
We overlaid two published cryo-EM structures of the human α4β2 nicotinic receptor, one holding nicotine and one holding acetylcholine. In all three pockets the two molecules sit about 1 Å apart. Here is what that shows, and what it doesn't.
We Followed One Neuron Through a Map of the Human Brain — Methods, Numbers, and What We Got Wrong
We opened the public H01 human-cortex connectome and counted every input to a single layer-5 pyramidal neuron: 6,131 synapses from 4,761 axon segments. Here are the methods, the figures, and the caveats our video could only hint at.