Role of olfactory cues in the radial maze performance of rats.

Contribution of the smell of food and odor trails to the performance of rats in a 12-arm radial maze was assessed in 12 rats. Choice accuracy was increased rather than decreased by omission of bait (Experiment 1). Maze arms entered during the first 6 choices in the 12-arm radial maze were randomly re-entered during the subsequent 6 choices in a parallel maze assembled from the same maze segments (Experiment 2). Error incidence increased from 1.33 to 1.94 per trial but remained below chance (3.0) when after 6 choices in radial maze A the rat completed the trial in an identical and similarly located maze B (Experiment 3). It is concluded that odor cues alone do not guide the animal's choice, but that they contribute to the complex sensory information essential for correct performance.