Fig. 6

Serotonin-LIR in the nervous system of Cateria styx. Anterior is up in all panels. A Schematic representation, ventral view. Grey shading on the left side marks the different body regions. B–E Confocal Z-stack projections of specimens co-labelled with 5HT (B–E) and DAPI (B). Colour legend in (B) applies to all panels. B Detail of ventral nerve cord and associated somata, segments 1-5, ventral view, introvert everted. C Detail of brain neuropil, ventromedial somata and convergent neurites, ventral view, introvert everted. D Detail of brain neuropil and associated somata, lateral view. E Detail of brain neuropil and associated somata, laterodorsal view. Dashed circles mark the position of the 5HT-LIR somata associated to the brain in (D–E). Scale bars: 20 μm. Abbreviations: asb, anterior somata of the brain; cne, convergent neurite; cnr, 5HT-LIR complete nerve ring; i, introvert; inr, 5HT-LIR incomplete nerve ring; n, neck; t, trunk; vms, ventromedial somata of the brain; vnc, ventral nerve cord; vncs5, ventral nerve cord somata segment 5. Numbers refer to segments