https://www.scientificamerican.com/article/why-your-brain-needs-exercise/ By: David A. Raichlen & Gene E. Alexander In the 1990s researchers announced a series of discoveries that would upend a bedrock tenet of neuroscience. For decades the mature brain was understood to be incapable of growing new neurons. Once an individual reached adulthood, the thinking went, the brain began losing neurons rather than gaining them. […]