Estrogen treatment increases the oral component of apomorphine-induced stereotypy.
Twelve weeks after surgery, sham operated intact and ovariectomized (OVX) female rats were treated for 3 days with either estradiol benzoate (50 micrograms/kg per day) or the oil vehicle. They were then tested for apomorphine-induced stereotypy 24 or 72 h after the last steroid injection. The data was collected and analysed in terms of both stereotypy ratings and individual behavioural responses. Estradiol, in those animals tested 72 h after estrogen, increased the frequency of oral behaviour in intact and in OVX groups. One possible explanation for the results is that estradiol may exert an anti-dopaminergic effect in the nigrostriatal system.
D000818:Animals; D001058:Apomorphine / Q000494:pharmacology*; D002369:Castration; D004298:Dopamine / Q000502:physiology; D004357:Drug Synergism; D004958:Estradiol / Q000494:pharmacology*; D005260:Female; D006801:Humans; D051381:Rats; D011919:Rats, Inbred Strains; D013239:Stereotyped Behavior / Q000187:drug effects*
D004958:Estradiol; D001058:Apomorphine; D004298:Dopamine