Figure 11

Horizontal vibratome sections to show the localization of the non-columnar olfactory neuropils and the regionalization of the olfactory glomeruli. Double labeling (C1-E) for synapsin immunoreactivity (SYN; red) and RFamide-like immunoreactivity (RF; green), or triple labeling for these two substances plus the nuclear marker (NUC; A, B); conventional fluorescence combined with the Apotome structured illumination technique for optical sectioning (A, B) and confocal laser scan microscopy (C1-E). A: superficial, tangential section of the right olfactory lobe (compare inset and Fig. 3D) to show the localization of non-columnar olfactory neuropil A. Cell cluster (10) is also visible. B: Overview over the arrangement of non-columnar olfactory neuropils C-F and the medial foramen (mF). The inset shows a low power view of this section (compare Fig. 3D). C1, C2: these two images show the non-columnar olfactory neuropils in B at a higher magnification. The images are from a stack of 30 optical sections covering 22 μm in the z direction. Image C1 is a projection of 6 sections covering z = 9.1 μm to z = 12.9 μm. Image C2 is a projection of 6 sections covering z = 18.2 μm to z = 21.2 μm. The non-columnar olfactory neuropil C is merged with D. Both are closely associated with the proximal bases of olfactory glomeruli and in some places even seem to overlap with the glomeruli (Fig. 9A1, 10B-C). D: single optical section (0.7 μm) from this stack at z = 1.5 μm showing the non-columnar olfactory neuropil C. It is not possible to decide if neuropil C does in fact connect with the bases of the glomeruli. E: Single optical section (0.44 μm) from another specimen. The olfactory glomeruli are subdivided into a cap region (Cp) that shows only synapsin immunoreactivity (red) and a subcap (Sc) and base (Ba) region in which synapsin immunoreactivity overlaps with RFamide-like immunoreactivity (yellow/orange color). The boxed area is shown in a higher magnification in Fig. 11.