Plain wording

The arcuate body is built from four sublayers, and each neurotransmitter population innervates its own subset of them.

slug arcuate-body-four-sublayer-differentialrole empiricalpanel fig11C, fig11D, fig12

Staining several neurotransmitters at once separates arcuate body layers that synapsin staining alone leaves indistinct.

slug arcuate-body-layers-neurotransmitter-distinguishedrole empiricalpanel fig (arcuate body)

Every claim here is an anatomical observation read off the atlas volumes rather than a statistical test.

slug atlas-observational-scoperole scopepanel all figures (assessment)

Serotonin and octopamine/tyramine fibres fill the cheliceral neuropil most heavily and continue just medial to it.

slug cheliceral-neuropil-serotonin-tdc2-dominantrole empiricalpanel fig4Eiv, fig4Ev, fig4Eiii

The anti-GAD antibody stains only the outer edge of the whole-mount, so GABA patterns in the deeper neuropils cannot be trusted.

slug gad-antibody-peripheral-penetration-onlyrole methodologicalpanel all (assessment — stated in Results introduction)

The globuli cells at the mushroom body heads stain for ChAT and, more weakly, GAD, marking them as cholinergic and GABAergic.

slug globuli-cells-cholinergic-gabaergicrole empiricalpanel fig7H, fig7I

Serotonin completely fills the newly named hagstone neuropil, and its staining is what marks the structure's boundaries.

slug hagstone-neuropil-serotonin-definedrole empiricalpanel fig6Bi, fig6Ci, fig6Di

Serotonin fibres reach each leg neuropil from the dorsal-most tract and fill it as two equal halves around a central void.

slug leg-neuropil-serotonin-bilateral-innervationrole empiricalpanel fig2Bi

All four pairs of leg neuropils carry the same innervation pattern for every neurotransmitter mapped.

slug leg-neuropils-consistent-innervationrole empiricalpanel fig2

Uloborus diversus, a web-building spider, has complete mushroom bodies, and only allatostatin A is found throughout them.

slug mushroom-bodies-present-asta-exclusiverole empiricalpanel fig7A, fig7B, fig7E

Octopamine/tyramine fibres ring the edge of the opisthosomal neuropil and form a ladder of crossing projections toward its back.

slug opisthosomal-neuropil-tdc2-perimeter-ladderrole empiricalpanel fig3Bii, fig3Cii

Acetylcholine and octopamine/tyramine stain most strongly in the pedipalpal neuropil, and neither reaches its front portion.

slug pedipalpal-neuropil-chat-tdc2-dominantrole empiricalpanel fig4Bii, fig4Biii

The spider brain contains a protocerebral bridge, a candidate counterpart of the insect central complex used in path integration.

slug protocerebral-bridge-candidate-central-complexrole interpretationpanel fig (central complex candidate)

The protocerebral bridge is layered by transmitter, with GABA spanning it and octopamine, proctolin and acetylcholine in bands.

slug protocerebral-bridge-layered-transmitter-architecturerole empiricalpanel fig10Bi-x

A previously undescribed neuropil, named the tonsillar neuropil, stands out in the spider synganglion by its staining pattern.

slug tonsillar-neuropil-novel-structurerole empiricalpanel fig (tonsillar neuropil)

Serotonin fills the tonsillar neuropil's core, octopamine/tyramine forms a shell around it, and two peptides sit only at its rear.

slug tonsillar-neuropil-serotonin-core-tdc2-shellrole empiricalpanel fig9Ci-x

A three-dimensional atlas places GABA, acetylcholine, serotonin, octopamine and several peptides in the spider's neuropils.

slug uloborus-synganglion-neurotransmitter-atlasrole methodologicalpanel figs 1-13