How do sex hormones affect brain function?

Although we call estrogen, progesterone, and androgens sex hormones, they do more than just affect reproductive development. Sex hormones have strong influences on the brain and nervous system, and they have important roles in brain development and function. For example, estrogen affects both the anatomy and physiology of the part of the brain called the hippocampus. The hippocampus -- from the Greek word for seahorse because of its shape -- plays an important role in long-term memory, orientation, and navigation. This may explain why women are better at remembering anniversaries and have different ways of giving directions than men do. Because the hippocampus actually makes estrogens and androgens from cholesterol in the bloodstream, gender influences on the brain continue throughout our lifetimes. In Alzheimer's disease, the hippocampus is one of the first areas to be damaged. This results in the common early symptoms of Alzheimer's -- memory loss and disorientation. Androgens and progesterone affect nerve functions less than estrogens.