Maternal dietary NaCl intake influences weanling rats' salt preferences without affecting taste nerve responsiveness

The present study examined the relationship between maternal dietary NaCl intake during the period from conception through weaning and weanling rats' elective consumption of salt; the study asked whether or not changes in offsprings' salt intake was mediated by altered taste responsiveness. The subjects were the 21-day-old offspring of 24 adult female rats fed diets containing .08% (low), 1% (mid), or 4% (high) NaCl from conception through weaning. Maternal dietary salt levels influenced offsprings' salt intake. In long-term food choice tests, the mid and high salt rats ate more salted food and had higher salt preferences than the low salt animals; in long-term solution choice tests, the mid and high salt rats drank more saline and less water and had higher saline preferences than the low salt rats. Nevertheless, the group differences in salt preference were not due to changes in taste responsiveness. There were no differences between the groups in saline preferences in short-term tests or in the amplitudes of chorda tympani nerve responses to concentration series of several salts. The implications of these data for understanding the physiological basis for group differences in salt preference are discussed.