The maternal odors that a young male smells before weaning can have a profound effect on the sexual behavior of that individual as an adult.

That conclusion, evoking a kind of chemical Freudianism, emerged from experiments on rats at Johns Hopkins University.

The researchers found that male rats became sexually aroused and were able to achieve intercourse only when exposed to receptive females that smelled like the mothers they had suckled as infants.

The experiment went as follows: One group of male rat pups was allowed to suckle normal mothers. A second group suckled only mothers whose nipples and vaginas had been treated with citral, a lemon scent.

Then the young rats were raised in isolation from females and from both odors. At adulthood, about 100 days later, each rat was put in a cage with a female in "heat," either a normal female or one that been dosed with the lemon odor.

Males that had normal mothers failed to perform with lemon-scented females. Males that had lemon-scented mothers failed to perform with normal-scented females.

Each, however, mated normally with a female that smelled like its mother.

"These findings suggest," Thomas J. Fillion and Elliott M. Blass wrote in the journal Science, "that, at least for this mammal, the degree to which a feminine feature is sexually arousing to adult males can be established in the context of suckling."