Estrogen-induced changes in the microtubular system correlate with a decreased susceptibility of aging neurons to beta amyloid neurotoxicity.

A growing body of evidence suggests that estrogen has beneficial effects on Alzheimer's disease. However, the mechanisms underlying estrogen's neuroprotective effects are not completely understood. In the present study, we analyzed first whether estrogen protects mature hippocampal neurons against fibrillar Abeta-induced neurotoxicity. 17alpha-Estradiol and 17beta-estradiol partially prevented neuronal death induced by fibrillar Abeta. Estrogen-induced neuroprotection correlated with the formation of a more dynamic microtubular system, including an increase in the pool of unstable microtubules and the expression of juvenile microtubule-associated proteins MAP2c and MAP1b. These results provide further evidence that experimental conditions capable of increasing the pool of unstable microtubules might render mature hippocampal neurons resistant to the degeneration caused by fibrillar Abeta deposits.