AJP - Regulatory, Integrative and Comparative Physiology, Vol 269, Issue 3 603-R607, Copyright © 1995 by American Physiological Society
Cross fostering between normal and sodium-restricted rats: effects on peripheral gustatory function
L. M. Phillips, R. E. Stewart and D. L. Hill
Department of Psychology, University of Virginia, Charlottesville 22903-2477, USA.
Rats restricted of dietary NaCl prenatally and thereafter exhibit
abnormally low electrophysiological chorda tympani taste responses to
sodium stimuli as adults. Recovery of responses can be induced by ingestion
of NaCl, even at adulthood. To examine whether milk from sodium-replete
mothers enables functional recovery in sodium-restricted rats, we recorded
multifiber chorda tympani responses in adult animals that had been cross
fostered during the suckling period. Sodium-restricted animals cross
fostered to control dams for postnatal weeks 1 and 2 did not recover normal
sodium sensitivity. Surprisingly, control pups crossed to sodium-restricted
mothers from postnatal days 1 to 14 showed an exaggerated response to NaCl
as adults. These results indicate that milk from normal mothers ingested
during postnatal weeks 1 and 2 is not sufficient to restore gustatory
function in sodium-restricted rats. Importantly, it also appears that
events occurring during the early suckling period of control rats determine
long-term taste sensitivities to sodium.
