[Amino acids as olfactory stimuli in the Rana temporaria]

Stimulation of the olfactory receptors in the frog by 10(-3) and 10(-4) M solutions of 22 amino acids results in generation of slow potential and evoked waves in the olfactory bulb. The amplitude, duration and area of the slow potential, as well as the frequency of onset of the induced waves served as an index of effectiveness of the amino acids. All the amino acids were shown to be the effective stimuli, the irreplaceable ones being more effective as compared with the replaceable amino acids. Among the former, basic amino acids (lysine, histidine, arginine) were most effective.