The effects of intrastriatal hormones on the dorsal immobility response in gonadectomized male and female rats.
Previous research has shown that intrastriatal estradiol potentiates the dorsal immobility response in ovariectomized female rats. In order to test whether the gonadal steroid hormones act on the male striatum in the same way, gonadectomized male and female Long-Evans hooded rats were given bilateral intrastriatal implants of 17 beta-estradiol (17 beta-E2), 17-alpha-estradiol (17-alpha-E2), 2-hydroxyestradiol (2-OH-E2), 4-hydroxyestradiol (4-OH-E2), or cholesterol. Four hours after the hormone implant the dorsal immobility response (DIR) was measured. In the ovariectomized females, the DIR was significantly potentiated only by 17 beta-E2 and 17-alpha-E2. In the castrated males, the DIR was significantly potentiated by 17 beta-E2, 17-alpha-E2, 2-OH-E2, and 4-OH-E2. While the DIR durations did not differ between males and females after intrastriatal cholesterol, the males had significantly longer DIR durations after each of the other hormones. These results are discussed in terms of estradiol stereospecificity and the properties of catechol estrogens in male and female rats.
Van Hartesveldt
C
C
Psychology Department, University of Florida, Gainesville 32611.
Cottrell
G A
GA
Meyer
M E
ME
D000818:Animals; D001522:Behavior, Animal / Q000187:drug effects*; D002369:Castration; D003342:Corpus Striatum / Q000187:drug effects / Q000502:physiology*; D004343:Drug Implants; D004958:Estradiol / Q000494:pharmacology*; D005260:Female; D007103:Immobilization; D008297:Male; D051381:Rats; D012727:Sex Characteristics
D004343:Drug Implants; D004958:Estradiol