Study Reveals "Awakened" X Chromosome May Explain Slower Cognitive Decline in Women

A recent study from the University of California, San Francisco (UCSF) suggests a biological basis for the observed difference in cognitive aging between men and women. Researchers found that a previously considered inactive X chromosome in females becomes active with age, potentially slowing cognitive decline. The study, conducted on genetically modified female mice equivalent to 65 human years, showed that this "silent" X chromosome activates genes that support brain development and connectivity. Professor Dena Dubal of UCSF's neurology department noted that the activation of the X chromosome could be a factor in the slower aging process observed in women's brains. The research identified 20 genes expressed upon activation of the silent chromosome, many of which are involved in improving brain development and neuronal connections. Unlike women, who have two X chromosomes, men possess only one, preventing them from experiencing this genetic "revival." This discovery has sparked interest among researchers seeking to understand how to amplify this phenomenon and apply it to brain aging research, potentially leading to new treatments for supporting cognitive function in older adults.