Fig. 3

Odor-induced neuronal activation shown by pERK immunohistochemistry in whole mounts of zebrafish olfactory bulb.

(a) The time course of the experiments is shown schematically. (b) Exposure to 10 μM cadaverine elicits robust and specific pERK antibody labelling of TAAR13c-positive neurons, consistent with previous observations⁸. (c) A schematic drawing of the olfactory bulb (OB; drawn using main positional information from ref. 4) shows the main glomeruli and glomerular groups (dlg, dorsolateral cluster; dG, dorsal cluster; mdG, mediodorsal cluster; lG, lateral chain; vpG, ventroposterior glomerulus; vmG, ventromedial glomeruli; vaG, ventroanterior glomerulus; maG, medioanterior cluster) visible from the dorsal (top scheme) and ventral (bottom scheme) side of the olfactory bulb; Tel, telencephalon; a↔p, anterio-posterior axis. (c) pERK levels (green) are visualized by immunohistochemistry. All pictures show maximum projections from confocal z-stacks of the bilateral olfactory bulb, as seen from dorsal (left column) or ventral (right column). Weak diffuse background fluorescence is present in all assay conditions. Top row, no activated glomeruli were seen in the negative control (water as stimulus). Second row, 10 μM cadaverine activates few glomeruli, one of them strongly (arrowhead). Third row, 100 μM cadaverine activates many glomeruli within the dorsolateral cluster. Fourth row, a mix of amines results in a strong activation restricted to the dorsolateral cluster. Bottom row, 3 μM PGF2α activates a single glomerulus (arrowhead) in the ventral olfactory bulb.