Fig. 2. The stimulatory effectiveness of monoamine and polyamine odorants compared to L-glutamine, the amino acid standard. All odorants were tested at 100 µmol l^–1. The average electro-olfactogram (EOG) response (mV) for each odorant was calculated from data obtained from three fish tested with only 100 µmol l^–1 concentrations of each of the test odorant and from the responses obtained to each stimulus in the pre-adapted state during the cross-adaptation experiments (N=20). Asterisks designate responses significantly greater than the response to AFW (one-way ANOVA, Dunnett's post hoc t-test; P<0.05). Values are means ± S.E.M. Abbreviations as in Fig. 1.