brains/Adult fly · female brain

The most heavily annotated connectome in existence. Descending neurons number only 1,276 — every behaviour the body performs passes through that bottleneck.

**Scope** Whole brain, adult female. No nerve cord. **Source dataset** flywire-fafb **Regions** 14 described

The anatomy below is published and ships with the library. Downloading the source dataset is only needed to compute exact per-region counts or to derive a circuit.

Composition: - Optic — 76,765 (Intrinsic to the optic lobes — 58% of the brain is vision) - Central — 32,298 (Intrinsic to the central brain) - Sensory — 11,415 (Periphery into the brain) - Visual projection — 8,046 (Optic lobes into the central brain) - Ascending — 1,989 (Nerve cord into the brain) - Descending — 1,276 (Brain out to the nerve cord — the motor bottleneck) - Visual centrifugal — 519 (Central brain back into the optic lobes) - Motor — 106 (Brain directly to muscle) - Endocrine — 69 (Brain to corpora allata and cardiaca)

- Superclass counts total 132,483 annotated neurons of the 139,255 segmented.