Lateral preoptic lesions in rats separate urge to drink from amount of water drunk

Rats with bilaterally symmetrical lesions in the laterla preoptic area do not drink after acute intracellular dehydration, but they drink normally after water deprivation. They, like normal rats, also drink more when cellular dehydration is superimposed upon water deprivation. Unlike normal rats, however, rats with lesions in the lateral preoptic area do not increase their rate of lever-pressing in response to the combined stimulus. Thus, the urge to drink can be separated from the amount of fluid drunk.