OR-Z6 neurons preferentially project to a single glomerulus in the main OB. In situhybridization was performed on serial coronal cryosections of the entire OBs using a [32P]CTP-labeled antisense RNA probe of the OR-Z6 coding region. Subsequent counterstaining of periglomerular nuclei facilitated the identification of individual glomeruli in the glomerular layer (GL). Top panels, The dark-field photomicrographs illustrate that axonal projections ofOR-Z6-reactive neurons preferentially terminate onto a single ventromedial glomerulus in each OB, as depicted by thearrowheads. Bottom panels 1–3, The hybridization signals (white grains) shown for this specimen were evident in three consecutive 18 μm sections per bulb (boxed areas in top panels magnified).EPL, External plexiform layer; ONL, olfactory nerve layer. Scale bar: bottom panels 1–3, 50 μm.
