A study now underway plans to recruit some 8,000 women over age 65. The participants, who will randomly receive either estrogen or a dummy pill, will be monitored for eight to 10 years. Researchers also are uncovering the many players that interact with estrogen to help it carry out its actions. For example, researchers have found that a group of neurons, which are often damaged in AD, have receptors for both estrogen and a neuron-protecting chemical known as a nerve growth factor. Scientists also are finding evidence that estrogen may regulate other proteins that have been directly linked to AD as well as molecules specifically tied to memory.
Researchers hope to develop ways to cause selected benefits of estrogen in the brain.
In addition to mental function, estrogen also may affect mood and brain blood flow. Once the hormone's mechanisms are better understood, scientists plan to develop estrogen-like drugs that target specific brain actions. Estrogen's role in memory may be due to its affect on the tiny knobs called spines that protrude from a neuron's message receiving ends, known as dendrites. Spines are where important connections between neurons are made. The cells were taken from brain areas responsible for memory processes.