Odorant response selectivity is reduced in glomeruli from OMP^−/− mice.

<p>(<b>A</b>) Example odorant response selectivity patterns in 6 individual glomeruli; 3 OMP^−/− glomeruli (<i>top row</i>, traces 1–3) and 3 OMP^−/+ glomeruli (<i>bottom row</i>, traces 4–6). Each set of 4 traces corresponds to a single glomerulus' responsivity to 4 test odorants that were all presented at a concentration of 30 a.u.: butyl acetate (<i>BA, magenta</i>), methyl valerate (<i>MV, cyan</i>), <i>trans</i>-2-methyl-2-butenal (<i>2M2B, blue</i>), and 2-hexanone (<i>2HEX, grey</i>). Each set of traces is scaled relative to the maximum evoked response across all 4 odorants per glomerulus. Yellow bars indicate the time when odor stimuli were presented. (<b>B</b>) Percentage of OMP^−/− (<i>red</i>) and OMP^−/+ (<i>black</i>) glomerular populations that were categorized as having higher (<i>closed bars</i>) or lower (<i>open bars</i>) odorant response selectivity.