Sneak Peek! Child Stars: Then & Now

Find out where Kirk Cameron, Blossom's Mayim Bialik, the Charles in Charge girls and more child stars are in this excerpt from PEOPLE's new book, in stores June 23!

MAYIM BIALIK

Now: She hit the books – hard – earning her Ph.D in neuroscience at UCLA in 2007. "My thesis has a long, pretentious-looking title," says Bialik, 33. While she still reviews grants, Bialik jumped back into acting with roles on Curb Your Enthusiasm and Fat Actress. In 2008, she gave birth to her second child with husband Michael Stone. "I'm working overtime being a mom," she says. "But I'd love to do a sitcom again."