Today's Health|Science: telling the truth, prescribing pain pills, pushing memory's buttons, touring genetic history

Research shows that as many as 44 percent of parents who used egg donors have no plans to tell their children the truth about their origins, a figure that surprises psychologists and fertility specialists who had expected a higher rate of disclosure at a time when openness is encouraged about such matters. Cara Birrittieri (left, with son, A.J., daughter, Victoria, and husband, Jackson Smith) is set to have a talk with her 3-year-old daughter any day now, something that has been on her mind since Victoria was just a fetal ultrasound image.

Detecting drug abusers is not always so easy, and while physicians and nurses want to relieve suffering, they have to be careful that their efforts to treat legitimate pain do not end up feeding addictions.

As surgeons implanted electrodes in his brain, the 50-year-old man was suddenly transported to a moment three decades earlier. He was in a park with friends, and could see the clothes they were wearing and what the weather was like. The discovery was an accident - the surgery was intended to help him lose weight, which it didn't do. But his doctors hope it might lead to better care for patients with memory disturbances.

Dr. Diana Bianchi has a little side project. She's writing a travel guide. It's technically about the history of genetics and genomics, but it's really, like much of her work, about the intersections of discovery.

Also, is there any way to tell whether you are getting enough vitamin D and is there a 'universal solvent' available that is capable of dissolving everything?