In the 1990s, the number of children receiving services for autistic disorders is estimated to have risen by 556 percent. This astounding increase has raised the profile of this disease, and a panel of experts will address many different issues concerning autism at the California Institute of Technology's Biology Forum 2001, "Autism: Deciphering the Puzzle," at 8 p.m., April 20, in Beckman Auditorium at Caltech in Pasadena. It is free and open to the public.