Mapping of glomerular responses to aliphatic acids (C3 – C7). Odor maps were obtained from a single mouse. Retronasal stimulus was delivered for 30 s at 300 ml/min (upper panels), orthonasal stimulus for 10 s at 150 ml/min (lower panels). Percent dilutions in mineral oil are given in each panel. The resting fluorescence of olfactory bulb is shown (leftmost panel). Scale bar = 200 μm. No retronasal responses were found for hexanoic acid and heptanoic acid.