Figure 3.

Expression of the transgenic Ca²⁺ indicator. A, Expression of HuC::YC in the forebrain of a larva at 4 dpf (z-projection of stack acquired with two-photon microscope in vivo). Strong expression in neurons in the outer layers of the OB is indicated by white arrow. The asterisk denotes weak expression in deeper layers of OB. Arrowheads depict axon tracts projecting to the telencephalon (Tel). B, Individual neuron labeled by transient mosaic expression of HuC::GFP (5 dpf). A long axon (arrowhead) to the telencephalon is visible. The halo around the somatic and dendritic region is caused by strong fluorescence. Other fluorescent structures in the field of view were removed from the image for clarity. C, Expression of HuC::YC and dlx4/6::GFP in a double-transgenic larva (5 dpf). D, HuC::YC expression (green) and labeling with an anti-GABA antibody (red) in the forebrain of a larva at 5 dpf (z-projection of a small confocal stack). E, HuC::YC expression in an optical section through the adult OB (z-projection of a two-photon stack). HuC::YC⁺ somata (arrows) and projecting axons (arrowheads) are visible. No HuC::YC⁺ somata are found in the deeper layers (asterisk). AC, Anterior commissure; L, lateral; A, anterior; P, posterior; M, medial.