TheFlyBrain/neuronsReference
README

Fruit fly neuron types

Reference pages for 17 well-studied neuron types and families of the fruit fly, Drosophila melanogaster, each with a 3D view of its reconstructed cells, a plain-language summary of established findings, the TheFlyBrain experiments that measure it and peer-reviewed sources.

Every type listed here appears in the site’s MaleCNS display bundle: 626 reconstructed neurons of the 166,700 in the MaleCNS v1.0 model that the workstation simulates; these pages highlight 434 of them. To see every system at once, open the nervous-system explorer; for terms, see the glossary.

Vision: eye and optic lobe

From the photoreceptors of the compound eye, through the lamina, medulla and lobula, to the visual projection neurons that carry features to the central brain.

  • R1–R6 photoreceptors

    The six outer photoreceptors of each ommatidium, and the main input to motion vision.

    Compound eye (retina)16 of 626 cells in 3D1 experiment6 sources

  • R7 and R8 photoreceptors

    The two inner photoreceptors of each ommatidium: the basis of color vision and, at the dorsal rim, of polarized-light vision.

    Compound eye (retina)16 of 626 cells in 3D1 experiment5 sources

  • Lamina monopolar cells L1–L5

    The five lamina output neurons; L1 and L2 begin the ON and OFF pathways for motion vision.

    Lamina (optic lobe)82 of 626 cells in 3D5 sources

  • Mi and Tm medulla neurons

    Columnar medulla neurons that supply the ON (T4) and OFF (T5) motion detectors.

    Medulla (optic lobe)49 of 626 cells in 3D6 sources

  • T4 and T5 motion detectors

    The first direction-selective neurons of the visual system: T4 for moving bright edges, T5 for moving dark edges.

    Medulla (T4) and lobula (T5)60 of 626 cells in 3D5 sources

  • Lobula columnar (LC) and LPLC neurons

    Feature-detecting visual projection neurons that send each visual feature to its own optic glomerulus.

    Lobula and lobula plate107 of 626 cells in 3D10 experiments5 sources

  • LC4

    Loom-sensitive visual projection neurons that tell the giant fiber how fast an approaching object expands.

    Lobula25 of 626 cells in 3D8 experiments5 sources

  • LC10a

    Visual projection neurons tuned to small moving objects; males need them to orient toward and follow a female.

    Lobula29 of 626 cells in 3D6 experiments3 sources

  • LPLC2

    Ultra-selective looming detectors that respond to objects approaching on a collision course.

    Lobula plate and lobula32 of 626 cells in 3D8 experiments4 sources

Learning and memory

The mushroom body and the dopaminergic neurons that signal reward to it.

  • Kenyon cells

    The intrinsic neurons of the mushroom body, which represent odors sparsely for learning and memory.

    Mushroom body: calyx10 of 626 cells in 3D6 sources

  • PAM dopaminergic neurons

    Dopaminergic neurons that signal reward to the mushroom body.

    Protocerebral anterior medial cluster1 of 626 cells in 3D1 experiment3 sources

Courtship

Sexually dimorphic neurons that set a male fly’s courtship state.

  • pC1 and P1 neurons

    A doublesex-expressing cluster; in males its P1 neurons can initiate courtship and set courtship arousal.

    Dorsal posterior central brain near the mushroom body1 of 626 cells in 3D1 experiment5 sources

Descending and motor neurons

Neurons that carry commands from the brain to the ventral nerve cord, and the motor neurons that move the legs.

  • DNp01 (giant fiber)

    The giant fiber: a large descending neuron whose spike triggers a fast escape takeoff.

    Posterior brain2 of 626 cells in 3D6 experiments7 sources

  • DNa02

    A descending neuron whose activity predicts turning; it shortens the strides of the legs on the inside of a turn.

    Anterior dorsal brain2 of 626 cells in 3D8 experiments2 sources

  • Descending neurons

    About 1,300 neurons that carry commands from the brain through the neck to the ventral nerve cord.

    Brain to ventral nerve cord29 of 626 cells in 3D13 experiments5 sources

  • Leg motor neurons

    About 50 motor neurons per leg, recruited in order from slow, weak movements to fast, strong ones.

    Ventral nerve cord (thoracic ganglia)60 of 626 cells in 3D1 experiment4 sources