Amino Acids as Gustatory Stimuli in the Rat
Open Access
- 1 March 1962
- journal article
- research article
- Published by Rockefeller University Press in The Journal of general physiology
- Vol. 45 (4), 681-701
- https://doi.org/10.1085/jgp.45.4.681
Abstract
Neural activity in intact chorda tympani nerve of rats was studied with an electronic summator. Neural activity increased when amino acid solutions 0.01 M or above passed over the tongue. Response magnitude, at concentrations close to solubility limits for the amino acids tested, was: DL-methionine < DL-tryptophan < DL-valine < DL-alanine < glycine < 0.1 M NaCl. Maximum response magnitudes to 1 M D-, and 1.2 M DL-alanine, and 1.5 M glycine developed in 1 to 3 minutes. Following such stimulation, a 63 per cent reduction in response to 0.1 M NaCl occurred 60 minutes after the first stimulation (medians). The depression was still present 20 hours later. Responses to glycine and alanine were not depressed. Amino acids vs. water preferences were investigated. With ascending concentration sequences, rats selected low concentration DL- and L-alanine and glycine; accepted D-, L-, and DL-tryptophan and low concentration DL-methionine; and rejected high concentration glycine, DL-alanine, and DL-methionine. Descending sequences showed depressed and delayed selection of glycine and DL-alanine, and DL-methionine and D- and L-tryptophan rejection. Both groups rejected DL-valine. It is concluded that glycine and alanine receptor effects differ from those of NaCl, but that all three compounds may affect a common receptor site. Prior exposure to amino acids may modify subsequent neural and/or behavioral responses.Keywords
This publication has 7 references indexed in Scilit:
- Intestinal transport of sugars and amino acids.1960
- Single fiber gustatory impulses in rat and hamsterJournal of Cellular and Comparative Physiology, 1957
- [Role of olfacto-gustatory stimulations in the mechanism of regulation of alimentary intake].1956
- The Physiology and Histology of the Contact Chemoreceptors of the BlowflyThe Quarterly Review of Biology, 1955
- GUSTATORY NERVE IMPULSES IN RAT, CAT AND RABBITJournal of Neurophysiology, 1955
- [Ingestion of food as a function of the composition of the diet; application to the regulation of the nitrogen requirements in the rat].1951
- Gustatory nerve discharge in normal and adrenalectomized rats.Journal of Comparative and Physiological Psychology, 1950