Good uterine environment enhances learning in mouse offspring

For the first time researchers have found that the environment in which a fetus develops can have a positive effect on cognitive development. Researchers have long known that a poor prenatal environment?exposure to drugs, alcohol or malnutrition?can damage fetal development.

'But this is the first paper that shows a broad range of positive effects of the uterine environment,' says University of Connecticut psychologist Victor H. Denenberg, PhD, who conducted the study along with Blair Hoplight, also of UConn, and Larry E. Mobraaten, PhD, of the Jackson Laboratory in Bar Harbor, Maine.

The key to the study were techniques that allowed the researchers to control for factors other than uterine environment that could affect cognitive development. To start, Mobraaten chose to use genetically identical mouse embryos of a strain known as BXSB/MpMob-+Yaa. The BXSB strain shows signs of lupus-like autoimmune disease as well as brain anomalies similar to those seen in human dyslexics.

One-third of the embryos developed normally within their BXSB mothers, who then raised them to adulthood. Another third were transferred into females of a non-autoimmune strain of mice called CB6F1 hybrids, who then raised the pups.

And to control for any impact the transfer technique might have on fetal development, Mobraaten implanted the last third into BXSB surrogate mothers. After birth, CB6F1 foster mothers raised these pups to account for possible differences in rearing by the two mouse strains.

The researchers found huge differences in behavior between the mice that developed in the BXSB females and those who developed in the CB6F1 uteruses, says Denenberg. All the mice showed normal learning curves on a battery of learning tasks, but the mice that developed in the uteruses of CB6F1 performed much better on the tasks than the other two groups.

'Certain uteruses seem to enhance [a fetus?s] cognitive abilities,' say Denenberg.

Mobraatenis in the process of devising studies that may be able to figure out why some wombs are better than others.

Even more exciting than the study?s findings is the implications this study has for future work on fetal development, says Binghamton University psychologist William Smotherman, PhD. 'This research is excellent and thought-provoking and seminal in the jumping-off point it provides for other lines of research,' he says.

The study was published in the March issue of the British scientific journal NeuroReport (Vol. 9, No.4, p. 61.)