NICOTINE INTERACTS WITH SEX IN AFFECTING RAT CHOICE BETWEEN LOOK-OUT AND NAVIGATIONAL COGNITIVE STYLES IN THE MORRIS WATER MAZE PLACE LEARNING-TASK

The effect of sex and nicotine on cognitive style was examined in rats using a water maze task that allows differentiation between cognitive ability and style. During the 12-day acquisition period with the plat form in the same location (either visible or hidden) there were no eff ects or interactions attributable to nicotine and sex, either in terms of learning rate or asymptotic latency. On the final test day the pla tform was visible and shifted in its location, and on the first trial the new location was proximal to the rats starting position, in contra st to the more distal location of the platform during the previous acq uisition days, This platform relocation presented the rats with a choi ce between two competing cognitive styles: using local visual (look-ou t) cues vs. navigational cues. Performance on the test day yielded a n icotine x sex interaction, such that only saline-treated female rats s howed a clear preference for the perceptual-proximal look-out cognitiv e style by swimming straight to the newly-relocated visible platform w ith mean escape latency that approximated the limits of swimming speed , The other three groups did not differ from each other, and preferred navigational cues. The results show that male and female rats use dif ferent strategies in problem solving, and that nicotine shifts the fem ale pattern to that of the male. (C) 1998 Elsevier Science Inc.