Cast of "Thunderbolts"

Actors Florence Pugh, Sebastian Stan, Wyatt Russell, Hannah John-Kamen and Geraldine Viswanathan ("Thunderbolts*"); chief medical correspondent Dr. Tara Narula and ABC News correspondent Will Reeve with a look at a new FDA approved brain device that helped a music composer with Parkinson's disease; Shop GMA5k, featuring running apparel.