Michelle Freund, the director of the NIH NeuroBioBank, says she has witnessed significant progress in postmortem brain research in the four years since the organization was established, such as the potential for groundbreaking studies with a relatively new technology known as CLARITY (Clear Lipid-exchanged Anatomically Rigid Imaging/immunostaining-compatible Tissue Hydrogel). CLARITY enables researchers to view neurons three-dimensionally, and could be instrumental in identifying neuronal circuits and specific cell types involved in a number of brain disorders.
Mash insisted that insights like this can’t come fast enough. Despite growing public awareness of brain research and sophisticated research tools, there’s still the matter of securing brain donations. Donation advocates have made some progress on this front, especially among athletes: Recently, several sports figures, including three female Olympians in February, pledged to donate their brains to the Concussion Legacy Foundation; the former professional footballer Nick Buoniconti also committed to donating after being diagnosed with dementia last year. But the need for viable specimens is still substantial, Mash said. Across all banks in the country, she estimated that there may be “only about 5,000 donors per year.” My grandmother was the only brain donor I knew; other people I spoke to who are organ donors assumed they were brain donors, too.
In fact, the challenge of recruiting donors comes in part from the fact that organ donors are not automatically brain donors. “Donors need to specifically designate their brain for donation,” explains Howard Rosen, a professor of neurology at the University of California at San Francisco, whose work focuses on the early diagnosis of dementia. In the early 1990s, Mash went to the Florida legislature in an attempt to add brain donation to driver’s licenses alongside other organs and tissues, but failed. The separation between donations remains intact throughout the country.
Nina Silverberg, the director of the Alzheimer’s Disease Centers program at the NIH’s National Institute on Aging, says that a donation “is of much more value if we know about the person when they’re living”—that is, if the person has participated in a longitudinal study of brain function. Silverberg explains that the Alzheimer’s Disease Centers conducts annual tracking assessments that include cognitive, neurological, behavioral, and linguistic tests for observing the changes in brain function as people age.
Another major challenge, Silverberg says, is obtaining tissue from donors of varied backgrounds. “There’s a stigma in some cultures around even talking about donating organs, or even death at all, but it’s tremendously important that we get diverse populations to donate their brains,” so that resulting treatments are broadly applicable, she says. She highlighted the efforts of the African American Network Against Alzheimer’s.