Sex differences in brain and behavior: emphasis on nicotine, nitric oxide and place learning.

Although males and females are unmistakably different, the recognition of sex as a key variable in science and medicine is considered a revolution in some circles. Sex differences transcend reproductive functions, are evident in the structural and functional organization of the brain, and are reflected in group differences in cognitive abilities and behavior. Males and females have different neural organizational patterns for information processing and different strategies in problem solving. Research on sex differences not only provides descriptive data, but also allows us to elucidate mechanisms that underlie our behavior. In this review, sex differences in the central actions of nicotine (an addictive substance) and nitric oxide, and performance on active avoidance and place learning tasks are discussed as examples, and biobehavioral approaches relating to these topics are presented.