Electrical Responses of the Olfactory Tract to Some Chemical Stimulants in Carp

Abstract

Multifiber responses to olfactory stimulation with alcohols, acids and salts were recorded from the olfactory tract of carp.
1) Alcohols were found to be effective to the olfaction of carp, though the responses were small. We found a tendency that alcohols with longer carbon chain were more stimulative.
2) The magnitude of the initial excitatory response to the stimulation with HCI was large, while that to the stimulation with butyric acid was negligible. The pH value lower than 3.5 regard-less of the kind of acid, however, induced inhibitory responses, which may probably be nonspecific pharmacological effects rather than olfactory responses.
3) Monovalent cations and monovalent anions induced only the initial excitatory responses, and were not accompanied with the oscillatory responses. Divalent cations induced both the initial excitatory and oscillatory responses, but only inhibitory responses were observed with tri-valent cations. The responses to salts were concluded to be largely dependent upon the cations. The salts with monovalent and divalent cations were found to be olfactory stimulants in carp, while those with trivalent cations seemed to be injurious to the olfactory receptors.