Neuroscience Notes

Without the paired experience of dehydration and drinking, rats appear unaware of the significance of dehydration and its internal and peripheral signals. That is, they do not express searching out water and drinking. With specific experience, however,rats acquire the water-seeking behavior that leads to drinking.
Only rats that previously had the experience of being dehydrated and drinking showed appetitive behavior by a differential orientation to the water chamber (Fig. 3;ANOVA main effect for appetitive state [F(1,20) = 14.65,P< .05] with experienced-dehydrated rats spending a greater percentage of their time in the water room than experienced-nondehydrated rats (P< .05); difference between inexperienced-dehydrated and inexperienced-nondehydrated rats was not significant.
That the appetitive behavior for such a basic stimulus as dehydration is learned suggests that perhaps the same is true for other appetitive behaviors also considered biologically fundamental (e.g. Refs. [15,16], as per Ref. [10]).Nonetheless, at least at first glance, this does not appear to be the case for the feeding.