Slides containing thin slices of Albert Einstein's brain will go on display at Philadelphia's Mutter Museum, thanks to a donation from a neuropathologist who has been holding onto the samples for decades.

Lucy Rorke-Adams of the Children's Hospital of Philadelphia received the box of 46 slides in the mid-1970s from the widow of a physician who helped arrange the preparation of the brain samples, the Philadelphia Inquirer reported.

Thomas Stoltz Harvey, a doctor at Princeton Hospital, conducted the autopsy on the famed physicist just hours after his death in 1955. Apparently without the family's permission, Harvey preserved Einstein's brain and sectioned it into hundreds of specimens on microscope slides for study. The controversy, as well as the strange journey of Einstein's brain, are detailed in Michael Paterniti's book "Driving Mr. Albert."

Harvey and other researchers found nothing unusual about the brain's size, but there was evidence that Einstein's brain contained more than the expected proportion of glial cells, which play a role in supporting connections between neurons. Rorke-Adams, whose research focuses on comparisons of brain cells at different ages, said Einstein's brain looks remarkably youthful under a microscope: "“It does not show any of the changes that we associate with age," CBS Philly quoted her as saying.

More about Einstein and brains:

• Explore the brain's hidden frontiers
• Brain growth predicts IQ in preterm babies
• Celebrate a century of Einstein
• Einstein slideshow: A life of genius