Nun brains assist in dementia research

Education is a big part of the mission work done by the School Sisters of Notre Dame , so when then-University of Minnesota neurologist David Snowden approached the sisters in 1986 about entering into a research project that involved the donation of their brains posthumously, they seriously considered it.

“One of the wisdom figures stood up and said, ‘we’re not going to need our brains when we’re dead’,” Catherine Bertrand, provincial leader of the Mankato province , said. “They saw themselves as being educators in life, and they would love to continue to be educators in death.”

The Nun Study, as it’s called, has tracked the cognitive abilities and motor functions of more than 600 nuns over the past two decades and continues to study the donated brains as they’ve passed on.

The brains have been processed and placed in plastic containers, and sit shelved outside neuropathologist Dr. Karen SantaCruz’s office.

Since only about 50 of the nuns are still alive, the University now houses about 600 brains.

Although a majority of the work was done at the University of Kentucky after Snowden took a position there, the University of Minnesota regained possession of the Nun Study when he announced his retirement last year.

“This is where the study started when Dr. Snowden was at the University of Minnesota,” said Harry Orr, professor and director of the Institute for Translational Neuroscience. “And one of the larger convents of the sisters is located in Mankato.”

The nuns make for a very unique population to study, he said, because of their similar lifestyles.

“They don’t smoke, they don’t drink, so you can reduce the effects of some of these other environmental factors,” Orr said, “and focus in on other factors that might be harder to get your hands around in other population studies.”

Orr said the University also proposed taking the Nun Study in a very interdisciplinary direction going forward, incorporating investigators from a range of fields: education, imaging, neuroscience.

Among the study’s findings are a relationship between early childhood education and reducing the susceptibility to Alzheimer’s disease, he said. They also found a relationship between traumas to the brain, such as strokes, and an increased susceptibility to Alzheimer’s.

“We are thrilled,” said Michelle Barclay , vice president of programs for the Alzheimer’s Association Minnesota-North Dakota . “It gives us information about how people can age successfully, what we might be able to do to prevent or slow down Alzheimer’s disease.”

The Alzheimer’s Association will host “The Meeting of the Minds” regional conference this weekend, where Dr. Kelvin Lim , the study’s scientific director, will present the study to the Midwest Alzheimer’s community, she said.

Another interesting finding has been that some of the nuns brains look like they have Alzheimer’s, Barclay said, but the women weren’t exhibiting symptoms before they died.

“If that’s the case, there may be things you can do, even though you have the disease to slow down or prevent the expression of the disease symptoms,” Barclay said.

Major advances in Alzheimer’s research since the Nun Study began mean researchers now know what dementia looks like in the brain.

SantaCruz’s job involves studying slices of the brains, searching for patterns, such as the ones where the pathology indicated brain dementia but the annual cognitive tests showed otherwise.

The researchers then work to connect the dots to establish the relationships, comparing the brain data with the cognitive and motor skills tests from when the nuns were alive, and also information about their lives before the convent.

Since the materials arrived at the University, the administrative team under Orr has set up a budget for the next two years and started developing a framework for a second nun study.

Orr said they hope to enroll a second group of nuns and use strengths within the University, such as advanced magnetic resonance imaging and genetics, to continue studying the nuns.

— Emma L. Carew is a senior staff reporter.