The accessory neuropil and the deutocerebral organ. Histological sections of cell cluster (9/11), the accessory neuropil (AcN) and the deutocerebral organ (DO) in detail. A to C: Horizontal vibratome triple labeled against cell nuclei (NUC; blue), synapsin (SYN; red/white) and allatostatin-like (AST; green) immunoreactivity in higher magnification from Fig. 5C. In B1, only the SYN-channel and in B2, the AST- and the NUC-channel are displayed separately. Note that in F, the horizontal vibratome section with immunohistochemical labeling against SIFamide (SIF; black) is obtained from another animal, but in a similar section plane like A to C. D: A silver impregnation of a microtome slice is shown in a similar section plane. E and G display higher magnifications of the boxed areas, shown in D. Roman numerals I, II, IV and V identify unstructured neuropils within the olfactory neuropil (ON). Other abbreviations: arrow, corresponding cell cluster to the AcN; LAN, lateral antenna I neuropil; mF, median foramen.