Fig. 10

Protocerebral sense organs and their connection to the brain in Stylopallene cheilorhynchus (“Callipallenidae”). A 3D-reconstructed volume rendering of protocerebral sense organs and the brain, μCT scan, lateral view. The arrow points at the lateral sense organ nerve. The stippled bracket indicates the position of the section shown in E. Note that several R-cell axon bundles and the lateral sense organ nerve are slightly damaged. B–F: Orcokinin (ORCO, green) coupled to tubulin (TUB, magenta; B–D) or synapsin (SYN, magenta; F) immunolabeling with nuclear counterstain and autofluorescence (AF + NUC, gray; left images in B–D, upper image in E). Black arrows mark selected orcokinin-ir somata in the lateral thickening and anterior soma cortex. Red arrows indicate the lateral sense organ nerve. Yellow arrowheads point to thin orcokinin-ir projections of afferents in the lateral sense organ nerve and the optic nerve branch targeting the antero-median neuropil (E,F). The stars indicate a rupture of the optic nerve at its point of entry into the soma cortex (due to vibratome sectioning). B Extended para-sagittal section. Note extensive orcokinin labeling in the lateral sense organ. C,D Slightly curved, para-sagittal 3D sections. Note finger-shaped apical extensions of the orcokinin-ir sensory cells in the lateral sense organ. E Extended cross section. Note the loop of the orcokinin-ir projections into the orcokinin-ir antero-median neuropil and additional projections (red arrowheads) passing the latter. F Oblique ventro-lateral view of apical portion of one brain hemisphere. Note absence of orcokinin signal in the visual neuropil and projections of antero-lateral orcokinin-ir neurons into the antero-median neuropil. Abbreviations: AE – anterior eye; AMN – antero-median neuropil; BR – brain; CHNV – cheliphore nerve; LO – lateral sense organ; LT – lateral thickening; PE – posterior eye; PNV – proboscis nerve; VN – visual neuropil