Lack of effect of specific sodium hunger on learned aversions to sodium and sucrose

Frumkin (1975) reported that sodium-deficient rats fail to learn taste aversions to NaCl. However, those rats were sodium-deficient at the time of testing as well as at the time of training; any learned aversion could have been masked by a strong sodium hunger. Rats were made temporarily sodium-hungry by injections of Formalin or aldosterone. They were then poisoned after drinking both an NaCl and a sucrose solution. Several days later they were tested for learned aversions. Rats trained under the influence of aldosterone did not differ from controls. Rats trained under the influence of Formalin acquired slightly weaker aversions to both NaCl and sucrose. Thus there is no evidence that sodium deficiency alters the associability of NaCl with poison.