Dataset · 1986
C. elegans complete connectome (White et al.)
The first complete nervous system ever mapped: 302 neurons and about 7,000 synapses, traced by hand over more than a decade. The dataset that founded the field.
| Species | Caenorhabditis elegans |
|---|---|
| Region | Whole nervous system |
| Cells | 302 neurons |
| Synapses | ~7,000 |
| Data size | <1 GB |
| Modality | Serial-section TEM, hand traced |
| Access | Open |
| Status | Released |
White and colleagues reconstructed the entire nervous system of the nematode by hand from serial-section electron micrographs — a decade of work producing 302 neurons and roughly 7,000 chemical synapses and gap junctions. It fits in under a gigabyte.
What it is good for. Understanding what a connectome is, without any of the scale problems. Every graph-analysis technique the site teaches can be rehearsed here in seconds, and the worm’s near-invariant cell lineage means the identity of every neuron is known and named.
What it does not support. The assumption that structure determines behaviour. The worm connectome has been complete for forty years and much of its dynamics is still unexplained, because neuromodulation and extrasynaptic signalling are invisible to EM. This is the field’s oldest and most instructive caution.
Where these numbers come from. White, Southgate, Thomson & Brenner (1986), Phil. Trans. R. Soc. B 10.1098/rstb.1986.0056; BossDB. DOI 10.1098/rstb.1986.0056.