1.   A knockout mouse does not turn heads, unless they belong to mouse geneticists.

2.   Abnormalities in the knockout mice were then studied for clues to the function of the missing gene.

3.   But in the new study, the researchers let the knockout mice give themselves cocaine.

4.   But Richard Axel of Columbia University, who has tested the same kind of knockout mouse, said he found the conclusions reasonable.

5.   But the knockout mice, deprived of the usual pheromonal cues, tried to mate with the strangers instead of attacking them.

6.   Dulac was even able to figure out, to some extent, what was going on in the heads of knockout mice.

7.   Experiments with the knockout mice suggest a different approach to treatment.

8.   Jaber has already shown that one neuroleptic, Haldol, calms the knockout mice.

9.   Knockout mice, however, could locate hidden cookies as well as normal mice.

10.   She then tested the response to strangers of knockout mice.