The brain — containing 100 billion neurons, 900 billion glial cells, 100 trillion branches and 1,000 trillion receptors — reacts to stimuli in a series of electrical bursts, spanning a complex map of connections. Whether calculating an algorithmic equation or learning the tango, our brain continuously changes in response to our ideas, actions and activities.

Each time a dance step is learned, for instance, new pathways are formed. “Dancing is excellent for the brain and body,” says Vincent Fortanasce, MD, clinical professor of neurology at the University of Southern California in Los Angeles. He wrote the Anti-Alzheimer’s Prescription. “Not only are you moving around more, your brain is in constant motion as it recalls steps and movements.”

Until recently, conventional wisdom held that our brains were intractable, hard-wired computers. What we were born with was all we got. Age wore down memory and the ability to understand, and few interventions could reverse this process. But increasingly, evidence suggests that physical and mental exercise can alter specific brain regions, making radical improvements in cognitive function. “When you challenge the brain with new skills and new ways of doing things, it increases connections in the brain,” says Ericka P. Simpson, MD, a neurologist who co-directs the MDA Neuromuscular Clinics and directs the ALS clinical research division at the Methodist Hospital System Neurological Institute in Houston. “It increases synaptic density.”

With nearly 72 million Americans turning 65 over the next two decades, physicians need the tools to handle growing patient concerns about how to best maintain brain health. Armed with this new brand of science, frontline physicians will be better equipped to address the needs of aging baby boomers, already in the throes of the brain fitness revolution. “They are the gatekeepers of information, and people listen,” says Eduardo Locatelli, MD, MPH, a neurologist and medical director of the Florida Neuroscience Center in Fort Lauderdale. Dr. Locatelli implements brain fitness techniques for his postsurgery epilepsy patients as well as patients who present with mild- to moderate-stage Alzheimer’s and dementia. “Encourage new experiences. … Use it or lose it. Challenge it and gain.”