Testosterone has rewarding affective properties in male rats: implications for the biological basis of sexual motivation.

Evidence from mammalian species, including humans, suggests that testosterone (T) enhances motivational aspects of sexual behavior, although the mechanism by which T exerts this effect is unknown. The hypothesis that increases in plasma T have rewarding affective properties was examined. Acute elevations of plasma T were induced in intact male rats by systemic administration of a recently developed testosterone-hydroxypropyl-beta-cyclodextrin inclusion complex that mimics pulsatile release of the hormone. In a conditioned-place-preference paradigm, rats displayed a preference for an environment previously paired with T administration (800 micrograms/kg and 1,200 micrograms/kg) as opposed to an environment paired with saline administration, indicating that T has rewarding affective properties. The findings suggest that T may enhance motivational aspects of mammalian sexual behavior by facilitating acquisition or expression of learned associations between environmental stimuli and sexual activity.