Strain and sex differences in amphetamine-induced rotation.

Studies of rotational behavior in female rats have investigated Fischer, Sprague-Dawley, Madison, WI, and Holtzman strains. The present study of amphetamine-induced rotational preference looked at the most widely used of the pigmented strains, Long-Evans hooded rats, examining rotation in females and comparing rotational magnitude and direction to males of the same strain. We corroborate in Long-Evans animals the greater rotation of females, but our findings oppose the right-sided female and left-sided male rotational preferences reported in earlier studies. Only female rats in this experiment had a significant directional bias, and it was to the left. This result strongly points to the importance of strain in the lateralization expressed by rotation.