Fig. 1

Fig. 1 (a) G_o-ir (green) is seen in a sparse population of pear-shaped cells in horizontal sections of the olfactory epithelium (short-fixed), using DAPI as counter-stain (blue); r, radial distance. Top right inset at higher magnification shows a G_o-ir-positive cell (green), co-labeled with zns2 (red), and visible nucleus (DAPI, blue). Bottom left inset at higher magnification shows a G_o-ir-positive cell with initial axon segment (ax) and cap (cp). (b) At higher magnification the apical position of G_o-ir-positive cells (green) is clearly visible. ø_v, vertical cell diameter; ø_h, horizontal cell diameter; h, laminar height; dotted half-circle, the apical dendritic part of G_o-ir-positive olfactory sensory neurons resembles a cap. (c) Nine G_o-ir-positive cells show the typical range of morphologies for these neurons. (d) Whole mount of adult zebrafish olfactory bulb double-labeled with anti- G_o and anti-zns2 antibodies, dorsal view. Zns2 labels all glomeruli, whereas G_o-ir labels a single medial glomerulus (yellow).The olfactory nerves were cut at the entrance to the olfactory bulb before staining. (e) Horizontal vibrotome cross-section (100µm) reveals the extremely dorsal position of the Go-immunoreactive glomerulus in each olfactory bulb. A single, thick axon bundle is seen entering the glomerulus. (f,g) One shape parameter and three spatial parameters were quantified for the G_o-ir-positive cell population, and shown as histogram (f) and empirical cumulative distribution function, ECDF (g). From left to right: ratio of horizontal to vertical diameter, laminar height (normalized to maximal height), radial distance (normalized to maximal radius), and number of cells per 10µm horizontal cross section of the olfactory epithelium; x axis units and labels are valid for both (f) and (g). Scale bars correspond to 50µm (a), 5µm (b), and 100µm (d, e).