One protein restored memory, balance and bone in older mice

Restoring a brain protein called Menin in older mice improved their memory, balance, bone mass and skin thickness within 30 days, researchers at Xiamen University reported in PLOS Biology. The protein, which helps restrain inflammation in the hypothalamus, declines naturally with age in a specific group of neurons. When the team disabled it in mice, inflammation rose and memory got worse. When they restored it in 20-month-old animals, several of those changes reversed. A separate finding caught their attention. Menin's decline reduced an amino acid called D-serine, important for learning. Giving older mice D-serine in their drinking water for three weeks improved their memory tests, though it did nothing for their bones or skin. The researchers are careful to note the work is in mice, and that human trials so far are small and mixed. "D-serine is a potentially promising therapeutic for cognitive decline," said lead researcher Lige Leng. For now, it stays in the maybe column.