Fig. 6. Representative recordings of electro-olfactogram (EOG) cross-adaptation experiments prior to (i), during (ii) and after (iii) adaptation to: (A) a mixture of 0.1 mmol l^–1 L-amino acids (AA; alanine, arginine, glutamate and methionine), (B) a mixture of 0.3 µmol l^–1 bile salts (BS; sodium taurocholate and taurolithocholate), (C) 40 µmol l^–1 ATP (compounds containing phosphate groups result in positive EOG deflections in goldfish), and (D) a mixture of polyamines (PA; 10 µmol l^–1 putrescine and cadaverine and 3 µmol l^–1 spermine). The adapting solution is underlined. The concentrations of the test solutions varied: in A, PA = 20 µmol l^–1 putrescine, cadaverine and 2 µmol l^–1 spermine) and BS = 10 µmol l^–1 TCA and TCLA; in B, AA = 10 µmol l^–1 alanine, arginine, glutamate and methionine and PA = 3 µmol l^–1 putrescine, cadaverine and 1 µmol l^–1 spermine; in C, AA = 100 µmol l^–1 arginine, methionine, alanine and glutamate and PA = 10 µmol l^–1 putrescine, cadaverine and 2 µmol l^–1 spermine; in D, AA = 100 µmol l^–1 alanine, arginine, glutamate and methionine and BS = 5 µmol l^–1 TCA and TCLA; ATP = 40 µmol l^–1. Upward deflections from the baseline are negative. Responses that are positive (downward) deflections were offset to enable comparison. Scale bars, 0.5 mV (vertical); 30 s (horizontal).