Rejuvenating the Brain With Chronic Exercise Through Adult Neurogenesis

TRINCHERO, MARIELA F.; HERRERO, MAGALÍ; SCHINDER, ALEJANDRO F.

Frontiers in Neuroscience

Frontiers

Año: 2019 vol. 13

The aging brain presents a general decline in plasticity that also affects hippocampalneurogenesis. Besides the well-known reduction in the rate of neuronal generation,development of new neurons is largely delayed in the aging brain. We have recentlyshown that this slow development is accelerated when middle-aged mice performvoluntary exercise in a running wheel. It is unclear whether the effects of exercise onneurogenic plasticity are persistent in time in a manner that might influence neuronalcohorts generated over an extended time span. To clarify these issues, we examinedthe effects of exercise length in 3-week-old neurons and found that their developmentis accelerated only when running occurs for long (3?4 weeks) but not short periods(1 week). Furthermore, chronic running acted with similar efficiency on neurons that wereborn at the onset, within, or at the end of the exercise period, lasting until 3 months.Interestingly, no effects were observed on neurons born 1 month after exercise hadended. Our results indicate that multiple neuronal cohorts born throughout the exercisespan integrate very rapidly in the aging brain, such that the effects of running willaccumulate and expand network assembly promoted by neurogenesis. These networksare likely to be more complex than those assembled in a sedentary mouse due to thefaster and more efficient integration of new neurons.