Influence of Salt Deficiency on Taste Sensitivity in Human Subjects

Abstract

IT appears to be well established that definite changes in preference and aversion behaviour can be elicited as a result of certain physiological changes in the animal^1–3; for example, the effects of salt deprivation, adrenalectomy, lack of food and insulin injections on the preference–aversion behaviour of rats for salt and sucrose solutions respectively. That taste stimulation is an important determinant of this behaviour has been demonstrated by Pfaffmann⁴, who found impairment in preference-aversion behaviour following bilateral removal of the chorda tyinpani and IXth nerves in rats. Richter⁵, Hartridge⁶ and Young³ have suggested that certain physiological needs result in a change in taste sensitivity for the needed substance and that the changes in taste sensitivity are peripheral in nature. However, on the basis of electrophysiological work Pfaffmann and Bare⁷ report “that salt deficiency does not alter the sensitivity of the taste receptors”, and Pfaffmann and Hagstrom² conclude “that the enhanced sugar preference shown in behaviour studies following the injection of insulin is not associated with a change in taste sensitivity”. Since these conclusions are based on records of afferent nerve impulses in the chorda tympani nerve the possibility of changes of a central origin in taste sensitivity are not excluded. In fact, Pfaffmann⁸ has recently suggested that the behavioural changes referred to above “reflect not a change in the peripheral afferent neural message but changes in its significance for central neural processes”.