From the article:
Previous research has already demonstrated that exercise after brain injury can help the repair mechanisms. This new study shows that exercise before the onset of damage modifies the brain environment in such a way that the neurons are protected from severe insults. The study used an experimental model of brain damage, in which mice are exposed to a chemical that destroys the hippocampus, an area of the brain which controls learning and memory. Mice that were exercised regularly prior to exposure produced an immune messenger called interleukin-6 in the brain, which dampens the harmful inflammatory response to this damage, and prevents the loss of function that is usually observed.
Pharmacological therapies to downregulate inflammation and address cognitive decline in older adults, and those with Alzheimer’s disease, have been less successful. This research helps understand how exercise could be used to affect the path of many human conditions, such as neurodevelopmental disorders and neurodegenerative diseases. In addition, as a chemical model of neuronal damage was used, it also raises the possibility that exercise could offer protection against the potentially harmful effects of environmental toxins.