1.   Eight week old female outbred Wistar rats were housed individually.

2.   And at the University of Catania in Italy, researchers using immune cells from female rats succeeded in stimulating cell division with GnRH.

3.   As it turns out, the female rats generate airborne chemical signals called pheromones that either enhance or suppress the fertility of their neighbors.

4.   As studies of female rats have revealed, the beta receptor abounds in the urogenital tract.

5.   But stimulated clitorises in female rats, he said, are harder to measure.

6.   Consistently, Isenberg said, female rats pulled their paws away from the source of growing pressure sooner than male rats.

7.   Female rats are better able to breathe in low oxygen than male rats, especially when their progesterone levels are highest.

8.   For example, she is particularly excited about one project in her lab that focuses on how female rats control the number of male and female offspring they bear.

9.   In a new study conducted with female rats at the University of Texas Medical School at Houston, testosterone injections prevented a key biochemical abnormality occurring in the disease.

10.   In studies, male rats showed much more muscle damage after exercises that emphasized muscle extensions than did female rats.