In this study we examined whether the food-reinforced alternation performance was associated with increased acetylcholine output in the dorsal hippocampus. Rats were trained to acquire the task using a T-maze. The control group consisted of rats introduced into the T-maze to run only on the day of dialysis. Acetylcholine release increased significantly in control rats only in the first 10 min after they were put into the T-maze. In trained rats acetylcholine output increased in the waiting cage as well as during trials in the T-maze. The increase in acetylcholine output in rats that had learned the task was significantly greater than in control rats.