Brains of rugby players aid groundbreaking research

Scientists have made a breakthrough in understanding chronic traumatic encephalopathy (CTE), a neurodegenerative disease linked to repeated head blows.

Neuroscientists at the University of Auckland’s Centre for Brain Research examined brain tissue, primarily from former rugby players, that was donated to the Neurological Foundation New Zealand Human Brain Bank, the Australia Sports Brain Bank, and the Boston UNITE Brain Bank.

Their study, published in the journal Acta Neuropathologica, sheds new light on how specific cells respond to damage from repeated head knocks.

Lead author PhD researcher Chelsie Osterman says the breakthrough in understanding the mechanisms driving the disease paves the way for new treatments that target inflammatory markers in the brains of people with CTE.

The researchers discovered a unique distribution of inflammatory markers clustered around the distinctive lesions in the brain used to diagnose CTE in people after they pass away. These markers suggest astrocytes – star shaped brain cells that support brain function - could be reacting to damage to blood vessels in the brain after head injuries.

“Astrocytes may play a more pivotal role in the disease than previously thought,” she says.

The research opens possibilities to better understand why some people who suffer repeated head injuries develop CTE, while others do not, says Osterman.

“Our new insights could be used to find ways to diagnose CTE in living people, potentially through MRI scans, whereas currently diagnosis is only possible after a person has died.

“This could also be used to develop ways to assess how the disease is progressing,” Osterman says.

Senior researcher on the study, Dr Helen Murray, says research into CTE is a relatively new science. The major hallmark of the disease is the accumulation of tau proteins in the brain, which can only be confirmed after death.

Tau is a normal protein found in the brain, however in CTE brains, tau ‘tangles’ in a specific region. Tau tangles impair the brain’s ability to function normally and are also found in the brains of people with Alzheimer’s and dementia.

But the new research findings add astrocyte reactions to the buildup of tau.

“Many of these astrocytes appeared to be responding to leaky blood vessels and trying to protect the brain from further damage. This discovery points to inflammation and vascular health as promising areas for future therapeutic strategies,” Murray says.

The vascular inflammation pattern was observed in CTE cases from all three brain banks, suggesting it is a consistent feature of the disease.

Murray says the findings underscore the importance of examining the broader network of cellular changes that might influence the disease, as well the well-known tau tangles.

“Overall, the study provides a more comprehensive picture of how the brain’s support cells may contribute to - or help counteract - the damage in CTE,” she says.