Estrogen receptor β is the predominant isoform expressed in the brain of adult and fetal sheep

Objective: The objective of this study was to examine the expression of estrogen receptors α and β in the cerebral cortex of the adult and fetal sheep. Study Design: A reverse transcriptase–polymerase chain reaction–based approach was used to examine the expression of ovine estrogen receptor α and estrogen receptor β in the cerebral cortex of 4 adult and 2 fetal sheep. Results: Estrogen receptor β was expressed in the 4 adult and 2 fetal brain samples. Estrogen receptor α expression was seen in only 1 adult brain and 1 fetal brain. Conclusion: Estrogen receptor β is the predominant isoform expressed in the cerebral cortex of both adult and fetal sheep. These data may have implications for the many important actions of estrogen in the adult and developing ovine brain. (Am J Obstet Gynecol 2001;184:1077-9.)