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As a runner, that struck me as some very good news (more than a decade later, I'm doubting the memory part, however).
Now scientists in Germany have learned more about how exercise induces stem cells in the brain to form those new neurons. It turns out that the brain chemical serotonin – the same one that is linked to depression – is required for exercise to stimulate those new neurons to form.
The German group used two groups of mice, one that made serotonin and one that didn’t. The mice that didn’t make serotonin were able to form new neurons throughout their lives, as is normal, but didn’t make any extra after bouts of running on their wheels.
The mice with normal levels of serotonin, on the other hand, saw a profusion of new neurons forming from the brain’s stem cells after exercise.
Back in 2007, the New York Times ran an aptly named story “Lobes of Steel” about Gage’s work, in which he is quoted:
“We’ve always known that our brains control our behavior, but not that our behavior could control and change the structure of our brains.”Now with the German work, we know more about how that behavior controls the brain.
Science Daily ran a story about the current work, which was published May 8 in the Journal of Neuroscience:
Deficiency in serotonin, popularly known as the "molecule of happiness," has been considered in the context of theories linking major depression to declining neurogenesis in the adult brain. "Our findings could potentially help to develop new approaches to prevent and treat depression as well as age-related decline in learning and memory," said Dr. Klempin and Dr. Alenina [authors on the study].No word on the endorphin high experienced by either group of mice after exercise.
Klempin F, Beis D, Mosienko V, Kempermann G, Bader M, Alenina N (2013). Serotonin is required for exercise-induced adult hippocampal neurogenesis. J Neurosci. DOI: http://www.ncbi.nlm.nih.gov/pubmed/23658167