Cuba neuroscientist: More collaboration needed to find cause of 'sonic attacks'04:20
Dr. Mitchell Valdes spoke with NBC's Andrea Mitchell about factors that would help in identifying the cause of "sonic attacks" on U.S. diplomats in Cuba.
Trump tells Pelosi State of Union is on, denies security concerns03:58
Rep. Panetta: President ‘dialing up the rhetoric’ with response to Speaker Pelosi06:50
Trump to deliver State of the Union Jan. 29, dismissing Pelosi’s proposed postponement02:29
Celebrity chef José Andrés helping federal workers in need03:41
Supreme Court takes up gun rights case for first time in a decade02:53
Sherrilyn Ifill discusses Trump’s policies and Martin Luther King Jr.’s legacy06:39