Motor System
In addition to differences in the behavior of female rats during different days of the estrus cycle, there are sex differences in the activation of motoric responses by drugs
- male rats show lower rates of rotational behavior, locomotor activity, and stereotypy in response to amphetamine than do female rats in estrus
- male rats also show lower level of dopamine release in response to amphetamine than do female rats in estrus
- castration of male rats has no effect on motoric responses nor on striatal dopamine release
- in contrast, ovariectomy in female rats significantly decreases amphetamine-induced dopamine release in the striatum and amphetamine-stimulated motoric behaviors
- important link between estrogen and dopamine-responsiveness in females