This is the cochlea as neurons. The Auditory preset grows a spiral ganglion: bipolar cells along 2.6 turns, each tuned to its place by the Greenwood map, high notes at the wide base and low notes at the narrow apex. A filterbank splits the sound into 64 bands; each band sets how fast the hair cell at that place releases transmitter onto its fibre, which drains with use, so every note opens with a burst and then settles. High-SR fibres are sensitive and never quiet; low-SR fibres wait for loud sound. Their axons twist into the auditory nerve. The raster runs from high notes at the top to low at the bottom, like a spectrogram.
Every neuron is simulated with its dendrites. Each cell has up to 31 dendritic compartments carrying voltage toward the soma, NMDA plateau spikes, a back-propagating action potential, short-term plasticity, STDP and memory consolidation, as in Dendrite Garden. All of it runs on the GPU.
Neurons only fire when pushed: by ambient input, by their neighbours, by pacemakers or by your tools. Homeostasis nudges each cell toward its target rate but never far enough to fire on its own, so with Ambient input at 0 the tissue goes quiet.
Each neuron grows one axon, a branching tree that reaches out to the cells it contacts. A spike leaves the soma, splits at every branch point and races down all branches at once; the sparks you see are those spikes.
Cell types (the Cells button) set who is in the tissue, how each type fires, what it looks like and who it wires to. The stain works like a Golgi stain: everything simulates, but only a fraction of cells are drawn.
Keys: O orbit, S excite, P pace, I probe, L lesion, W light, Z sleep, R spin, C cell types, Space pause, H hide panels. Right-drag pans in Orbit and rotates with other tools.
Synchronised activity can flash. Lower Trails and Speed if you are sensitive to flicker.
The original: Dendrite Garden.