During stepwise cue deletion, rat place behaviors correlate with place unit responses

The place behaviors of intact rats, and of those receiving fornix lesions, were examined in the radial-arm maze. A cue-restricted environment was constructed wherein the location of arms with food rewards were identifiable only by their position in relation to an intermittently rotated 4-cue set. Food obtainment was measured during a procedure in which either 1, 2 or 3 of the cues were removed during a block of test sessions. Control animals demonstrated place navigation abilities robust to the deletion of any 1 or 2 cues. The performance of lesioned rats declined in a manner consistent with the number of absent stimuli. The results indicate that the behavioral expressions of place knowledge relate to the responsiveness of hippocampal place cells.