SCENES FROM SCIENCE
Of rats and men
THE recent Gardner enquiry into the clusters of child sufferers from leukae- mia in the vicinity of nuclear establish- ments has presented the idea that radia- tion may have a mutagenic effect on the sperm of prospective fathers. Now, from the Washington School of Medi- cine in the United States, comes a suggestion that alcohol may have a mutagenic effect on the sperm of prospective fathers which affects the cognitive abilities and hormonal ba- lance of their offspring. The ground- work has been laid by experiments on rats. Researchers fed 15 male rats on a diet containing 6 per cent alcohol, which kept them intoxicated, for 39 days; after which, they were weaned off alcohol and mated with non-alcoholic females. The resulting male offspring were compared with a control group since earlier work had shown that the male offspring of alcohol-consuming rats showed hormonal imbalances.
It was observed to begin with that these male pups seemed to all intents and purposes not to differ from the control group — same physical develop- ment, same proficiency in performing physical and perceptual tasks — until it came to finding their way through a maze to a reward of food; when they took 50 per cent more time to learn the trick. (And they showed the hormonal imbalances already noted.) For these experiments young males were chosen because they were more sensitive to alcohol than their elders; the resear- chers mean next to compare cognitive abilities (measured by maze-solving) of female and male pups of older fathers.
Now we come to the trickier ground: comparison with humans. Other resear- chers have reported that sons of alcoho- lics are more liable to hormonal abnor- malities, and do less well in school, than either their sisters or the children of non-alcoholics. The Washington resear- chers know that more evidence is needed on both counts. In the case of their own work with rats, they have no mechanism to suggest for the occur- rence of the mutation in the genes, or for how it causes hormonal imbalance or cognitive deficiencies in male pups. They are only too aware that they are declaring their work prematurely such, in the United States, is the press- ure to publish. But it may turn out to be extremely important, as it implies that some changes affecting cognitive de- velopment are transmittable through the male. A fascinating idea!
William Cooper
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