Behavioral taste responses of developmentally NaCl-restricted rats to various concentrations of NaCl.

The behavioral taste responses of developmentally NaCl-restricted rats were examined with a brief-exposure taste test. Neurophysiological and morphological alterations have been reported in rats whose dietary sodium is restricted during pre- and postnatal development, yet there exists little data discerning their behavioral response to tastants. Control and developmentally NaCl-restricted rats were maintained on a low-NaCl diet and trained to lick from individually presented sipper tubes. Each subject received 4 days of testing on various NaCl concentrations. Results indicate that developmentally NaCl-restricted rats have dramatically increased lick rates to NaCl solutions. These responses are likely due to some combination of factors including (a) numbers and type of active chorda tympani fibers, (b) compensatory responses to NaCl-solutions from other nerves of the oral cavity, and (c) increased sensitivity of central taste systems to NaCl.