The Human Forebrain Has Discrete Estrogen Receptor Alpha Messenger RNA Expression: High Levels in the Amygdaloid Complex

Estrogen is considered to play an important role in neuropsychiatric disorders and the estrogen receptors mediate the action of the hormone. In the present study, the messenger RNA expression pattern of the estrogen receptor alpha subtype was identified in the post mortem human brain. High stringent in situ hybridization histochemistry was performed using a riboprobe specific for the estrogen receptor alpha subtype. The human brain was mainly characterized by abundant estrogen receptor alpha messenger RNA expression in the amygdala and hypothalamus, but labeling (lower) was also found in the extended sublenticular amygdala, cerebral cortex, and hippocampus. In the amygdala, the estrogen receptor alpha messenger RNA was preferentially expressed in medially-localized nuclei suggesting that estrogen regulates distinct human amygdala-mediated functions. The Cynomologous monkey brain was also examined in the present study and a similar distribution of the estrogen receptor alpha messenger RNA signal was observed in the human and monkey brain. However, the primate expression pattern differed in part from the known distribution in the rat. The current results show that estrogen receptor alpha messenger RNA is expressed in discrete areas of the human brain not only related to neuroendocrine function, but also emotion, memory, and cognition, which is consistent with the hypothesized involvement of estrogen in schizophrenia, affective disorders, and Alzheimers disease.