21.   Last year, Klar said, geneticists identified a gene that is present in normal mice but totally missing in the mutants.

22.   Nine out of ten normal mice survive this operation.

23.   Normal mice press up to eight times, then give up, Hen said.

24.   Normal mice that were treated also lost weight, albeit a smaller amount.

25.   Normal mice that were treated also lost weight, although a smaller amount.

26.   Not only did the mice that lacked NO savagely and obsessively attack normal mice, but they persistently tried to copulate with female mice despite their protestations.

27.   Normal mice lost body fat to a lesser degree.

28.   Normal mice treated with the hormone also ate less and lost nearly all their body fat, researchers found.

29.   Scientists have tried to speed things up by injecting cow tissue into normal mice.

30.   Tecott and his colleagues pinpointed the effects of the brain chemical by creating mutant mice that lacked the protein and ate more than normal mice.