specimen · domestic shorthair model · illustrative, v0.1 not measured · always
X-ray style illustration of a cat wearing a box-shaped paper bag over its head, with its brain, skull and ribcage visible through the x-ray

CATBRAIN

Felis catus

three real numbers from actual cat-brain tissue, and one made-up map to go with them

250M
cortical neurons
Jardim-Messeder et al., 2017
3.8 : 1
cerebellum to cortex neuron ratio
Jardim-Messeder et al., 2017
51,400
neurons per mm³, visual cortex
published estimate

What's real here, and what isn't

Those three numbers are measured. Neuroscientists dissolved slices of an actual cat's cortex and cerebellum into a cell-count slurry and counted nuclei one by one — the same technique that found dogs have roughly twice as many cortical neurons as cats.

Everything below this point is illustration, not data. Nobody has published a full wiring diagram of a cat's brain — no electron-microscope trace of which neuron connects to which, the way it's now been done for a fruit fly's entire nervous system. So the eyes above, and the sketch further down, are honest about that gap: a real brain, a made-up map of it.

An eye that follows

Real cats track motion with retinas built for catching movement in low light, not for resolving fine detail — part of why a laser dot works so well on them. This isn't that. It's a cursor-following script wearing a cat-eye costume.

move your mouse over the box — the pupils lean toward it, and blink on their own clock. it's animation, not a nervous system.

The plan

01
Gather the real numberscortical neuron count, cerebellar ratio, visual cortex density — pulled from published carnivoran studies
done
02
Draw a plausible circuitan invented wiring diagram in the fly site's visual language, not measured from any tissue
done
03
Wire up an interactionthe eyes above track a cursor — a script, not inference over a connectome
done
04
A real feline connectomeno lab has published one yet — a cat's brain is roughly a million times more neurons than a fly's
blocked
05
Rebuild this, for realif that dataset ever exists, this page is worth doing properly
open

Stated plainly