David Has His Darlene Back...

Sara Gilbert has joined the cast of THE BIG BANG THEORY as a series regular, reprising her role as "Leslie Winkle," Leonard's (Johnny Galecki) colleague and on-again-off-again love interest. The second season of THE BIG BANG THEORY premieres Monday, Sept. 22 (8:00–8:30 PM, ET/PT) on the CBS Television Network.

Gilbert is well known to television audiences for her Emmy-nominated role on "Rosanne," in which Galecki played her love interest. She recently made guest appearances on "ER" and "Private Practice."

THE BIG BANG THEORY, created by Chuck Lorre and Bill Prady, is a comedy centered around Leonard and Sheldon, brilliant physicists who understand how the universe works but struggle in their daily interactions with people, especially women. The series stars Johnny Galecki, Jim Parsons, Kaley Cuoco, Simon Helberg and Kunal Nayyar.