Long-lived cellular molecules in the brain.

In long-lived mammals, including humans, brain cell homeostasis is critical for maintaining brain function throughout life. Most neurons are generated during development and must maintain their cellular identity and plasticity to preserve brain function. Although extensive studies indicate the importance of recycling and regenerating cellular molecules to maintain cellular homeostasis, recent evidence has shown that some proteins and RNAs do not turn over for months and even years. We propose that these long-lived cellular molecules may be the basis for maintaining brain function in the long term, but also a potential convergent target of brain aging. We highlight key discoveries and challenges, and propose potential directions to unravel the mystery of brain cell longevity.