Posterior Deutocerebrum and Tritocerebrum. A: 3D-reconstruction of the mid-brain from ventral (see box). B: Horizontal vibratome section, triple labeled against cell nuclei (NUC; blue), synapsin (SYN; red) and allatostatin-like (AST; green) immunoreactivity in higher magnifications from Fig. 4A. C: A silver impregnation of a microtome slice is shown in a similar section plane. D: The fused columnar neuropil (CN) further dorsally with the same triple counter stains as in B. Numbers 6, 10 and 16 identify cell clusters. Other abbreviations: arrowheads: identifiable groups of single neurons showing ASTir; arrows: fibers with ASTir inserting the oesophageal commissure (OC); AIINv, antenna II nerve; AnN, antenna II neuropil; CA, cerebral artery; CB, central body neuropil; DCF, deutocerebral commissural fibers; iT, interconnecting tract; LAN, lateral antenna I neuropil; MAN, median antenna I neuropil; mPC, medial protocerebrum; OGT, olfactory globular tract; ON, olfactory neuropil; PB, protocerebral bridge neuropil.