Gender differences in Morris water maze performance depend on task parameters

This study demonstrates that the relative performance of male and female ra ts on a Morris water maze task changes when the task parameters are varied. In three separate experiments, male and female rats were tested on a diffe rent variation of the Morris water maze. In all cases, on each of 10 days o f testing, rats were given an initial trial in which the escape platform wa s randomly placed in a new position. A second trial was given one 1 h later . When the release position did not change between daily trials, no gender differences were observed. When the release position was changed between th e initial and subsequent trial, females, but not males, showed reduced rete ntion of the platform location on the second trial. This implies a male sup eriority for the task. However, a third manipulation of the task parameters demonstrated that females were as accurate and efficient as males at findi ng and remembering the platform location, even when released from a new pos ition, as long as major landmark cues in the room remained constant. This s tudy supports the hypothesis that male and female rats use different types of spatial cues when solving maze tasks, and stresses the importance of sep arating the effects of task variables from possible endogenous sender diffe rences in ability. (C) 1999 Elsevier Science Inc. All rights reserved.