Ageing in the brain: mechanisms and rejuvenating strategies

Ageing is characterised by the progressive loss of cellular homeostasis, leading to an overall decline of the organism fitness. In the brain, ageing is highly associated with cognitive decline and neurodegenerative diseases. With the rise in life expectancy, characterising the brain ageing process becomes fundamental for developing therapeutic interventions against the increased incidence of age-related neurodegenerative diseases and to aim for an increase in human lifespan and, more importantly, healthspan(definition). In this review, we will start by introducing the molecular/cellular hallmarks associated to brain ageing and their impact in brain cell populations. Following, we will assess emerging evidence on how systemic ageing translates into brain ageing. Finally, we will revise the mainstream and the novel rejuvenating strategies, discussing the most successful ones in delaying brain ageing and related diseases.