Motor System
Bottom line: changes in gonadal steroids that occur during the estrus cycle (primarily the rise in estrogen) stimulates release of dopamine within the striatum that leads to alterations in the behavior of the female rat.
- estrogen levels are elevated during late proestrus-early estrus (prior to, and during the start of behavioral estrus and ovulation); estrogen levels are lower at other times (e.g., diestrus)
- dopamine synthesis and release within the striatum is greatest during estrus
- administration of amphetamine can stimulate greater release of dopamine in the striatum of female rats in estrus in comparison to females in diestrus; this can be seen in tissue slices of striatum that are placed into a tissue chamber and perfused with amphetamine; this can also be seen in freely moving rats using microdialysis to sample dopamine release within the striatum after administration of amphetamine
- administration of amphetamine produced greater levels of stereotyped behavior (such as sniffing and head and forelimb movements) in female rats in estrus in comparison to those in diestrus