Humans aren't the only ones who grow forgetful as they age—fruit flies do, too. But because fruit flies have a lifespan of only about two months, they can be a useful model for understanding the cognitive decline that comes with aging. A new study published in Nature Communications shows that when a common cell structural protein called filamentous actin, or F-actin, builds up in the brain, it inhibits a key process that removes unnecessary or dysfunctional components within cells, including DNA, lipids, proteins and organelles.
The resulting accumulation of waste diminishes neuronal functions and contributes to cognitive decline . By tweaking a few specific genes in aging fruit flies' neurons, the researchers prevented F-actin buildup, maintained cellular recycling and extended the healthy lifespan of fruit flies by approximately 30%. Actin, a family of proteins that help give cells their shape, are abundant throughout the body.
F-actin forms filaments that are essential for maintaining cell structure and many other functions. The researchers, led by former postdoctoral scholar Edward (Ted) Schmid in David Walker's lab, noticed F-actin buildup in the brains of aging fruit flies and wondered if it contributed to brain aging and overall loss of organismal health. Their first clue of a correlation: Flies on a restricted diet both lived longer and had less F-actin buildup in their brains.
Their second clue: When treated with a drug known to extend lifespan, called rapamycin, t.