Conditioned rotation: a behavioral analysis.

Rats trained to turn in circles have been used by a number of investigators to study brain dopamine metabolism. We report the results of a behavioral analysis of conditioned rotation and describe the apparatus used in our laboratory to train rats and monitor their performance. A novel discrimination procedure was used which required each rat to turn left in one training chamber with one set of stimulus conditions and right in a different chamber. Water-deprived animals were trained to circle for a water reward. Initial acquisition of this task required 11 days of training. At the end of acquisition, a discrimination test indicated that turning in the left and right directions was under stimulus control of the chamber environment. We found that trained turning had a highly stereotyped temporal organization with a rapid movement component during which the rat executed the turn, and a longer pause time component during which the rat consumed the water reinforcer.