Figure 3.

Neuroanatomy of annelid representatives as revealed by a combination of immunohistochemistry (red) and cell nuclei labeling (blue). Schematic drawings depict a dorsal view of the head of the animal, with the brain outlined in red and clusters of small-diameter cells outlined in blue. Immunostainings were produced by the following antisera: anti-serotonin (a, c, d), anti-FMRFamide (b). Arrowheads indicate a narrow neuropil band connecting both cerebral hemispheres in (a), lateral protuberances of the central neuropil encased in dense assemblies of minute cell somata in (b), and laterally arranged somata showing serotonin-immunoreactivity in (c). ec circumesophageal connective. Scale bars: 100 μm.