Oestrogen, cognition and the maturing female brain.

Many women complain of memory and other cognitive difficulties at times that are associated with changes in ovarian steroid levels. However, the biological mechanisms through which ovarian steroids exert these effects remains poorly understood. Furthermore, the effect of hormone therapy, especially oestrogen therapy, on cognition and brain function in healthy women, and its role in the prevention of Alzheimer's disease, remains controversial. Here, we review the evidence that, in healthy women, ovarian steroids/oestrogen affects brain regions crucial to higher cognitive function at the macroscopic, microscopic, functional and neurotransmitter levels.