Conditioned thirst in rats

The purpose of these studies was to assess the appropriateness of control groups in previous thirst conditining studies and to demonstrate that conditioned drinking can be viewed as a classically conditioned appetitive response. In Experiment I (N = 48) thirst was conditioned by the procedure employed by Solomon and Swanson [see Mowrer (11)]. With the use of a "novel cage" group, suppression rather than enhancement of intake was obtained. These and other investigators' results were interpreted in the light of the appropriateness of control groups. In Experiment II (N = 30) rate demonstrated increased water intake at zero hours water deprivation in the presence of an external stimulus previously paired with an increasing motive state. Intakes monitored at half-hour intervals revealed that "low-to-high" drive associated stimuli did not affect overall intake but did induce differentiation in drinking patterns causing first enhancement and then reduction in intake amounts. The results were agreement with Seligman et al. (14) who suggested that elicitation of the prepared mechanism evokes drinking, but water regulation controls do not allow prolonged hyperdipsia.