Cues used by male and female hooded rats for locating a brightness change

Entries of and time spent in a novel Y-maze arm that had changed from white (during acquisition trials) to black (during retention trials) were investigated in male and female Long-Evans hooded rats after the apparatus had been horizontally rotated through 180 degrees or left undisturbed. Maze rotation reduced responsiveness to this arm in males but not in females. When each arm was associated with a different set of visual cues, males significantly chose the novel arm only in the presence of intra- and extra-maze cues either alone or in combination. Females significantly selected the novel arm only in the absence of either type of cue, and in the presence of intra-maze cues alone. However, when the duration of acquisition trials was increased from 6 to 12 min, females also selected the novel arm in the presence of both intra- and extra-maze cues. It was concluded that, while female rats appeared able to use egocentric (or response-related) cues for locating the novel arm, males were more dependent on allocentric (or place-related) cues following shorter acquisition trials. Because of the importance of such cues, it seemed that the task of recognizing which maze arm had changed in brightness defined the test as one of spatial memory. (c) 2006 Elsevier B.V. All rights reserved.