The electrical responses of the olfactory tract to amino acids in carp.

Abstract

The multifiber responses from the olfactory tract induced by the stimulation with amino acids of the olfactory mucosa were recorded in carp. By stimulation with an amino acid, the integration of the tract discharges increased initially, and showed up and down oscillation at the frequency of 10Hz. Both the height of the initial increase and the amplitude of the oscillation are good indicators of the sense of smell, because they increase proportionately with the logarithmic intensity of the stimulation. Using the above indicators, we concluded that the threshold concentration for L-glutamine was about 10-6M, and that the responses to L-glutamine, L-methionine, L-alanine and L-serine were bigger than those to L-proline and taurine when used in the same concentration of 10-3M. L-Lysine, L-arginine and L-glutamic acid elicited rather small oscillatory responses despite the large integrated responses.