Cover

Estrogens influence brain plasticity by enhancing the ability of neurons and glial cells to remodel their mutual connections. By using a combination of optical and molecular approaches, recent findings highlight how this is achieved through architectural changes of the cytoskeleton and cell membrane via the control of actin polymerization. Estrogens modulate neurite extension through the rapid, extranuclear activation of G proteins via ERα, leading to the recruitment of a c-Src/Rac1/Cdk5/WAVE1/Arp2/3 cascade. Through this cascade, estradiol supports the rearrangement of the actin cytoskeleton at sites of ongoing spine formation in cortical rat neurons. The parallel G protein-dependent activation of the RhoA/ROCK-2/moesin cascade contributes to this phenomenon. The identification of these original rapid actions of estrogen in brain cells may provide new tools to interfere with the gender-related degenerative changes observed in the brain throughout aging. From the article in this issue by Sanchez et al., pages 1193–1202.

The editors thank Dr. Ron Smith, Alcon Laboratories, Fort Worth, TX, for collaborating with the authors to create the figure on the cover.