Scientists have developed an innovative technique to observe Alzheimer’s disease as it progresses in the brain – a breakthrough that could accelerate the development of new treatments.

The new method uses light to detect and measure the build-up of amyloid plaques – sticky protein clumps that are a key characteristic of Alzheimer’s – at different depths in the brain.

It is the first time such measurements have been made in living animals as they move naturally, rather than under anaesthetic or in fixed positions.

The research was carried out by the University of Strathclyde in partnership with the Istituto Italiano di Tecnologia, the University of Padua and the Technical University of Denmark, combining expertise in neuroscience, physics and biomedical imaging.

Professor Shuzo Sakata at Strathclyde and senior author of the study said: “Being able to monitor changes in the brain as they happen – in real time and across different brain regions – is a major step forward.

“It will help researchers understand how Alzheimer’s disease develops and test whether new treatments are working, more quickly and accurately than before.”

A special fluorescent dye that attaches to amyloid plaques in the brain was used.

Ultra-thin optical fibres were then applied to shine light into the brain and measure how much of the dye was present – providing a clear picture of how much plaque had formed.

The system was tested in mice that had been genetically modified to develop Alzheimer’s-like symptoms. The results closely matched those seen in postmortem brain tissue, confirming the accuracy of the new technique.

The research was funded by the European Union’s Horizon 2020, the Medical Research Council, part of UKRI, and Alzheimer’s Research UK.

“This approach allows us to track the disease over time in the same subject, and opens new doors for studying the progression of Alzheimer’s and how it responds to treatment,” said Dr Niall McAlinden, co-author and expert in photonics at Strathclyde.

The team is now working to improve the system’s capabilities and explore its use in studying other characteristics of Alzheimer’s disease.

NeuroClin – formerly known as Glasgow Memory Clinic – has partnered with Advance Tests to launch Scotland’s first commercially available blood biomarker test for early Alzheimer’s detection.

Designed for people with mild cognitive impairment (MCI) – subtle problems with memory and thinking – the LucentAD Complete test helps determine whether these symptoms are likely due to Alzheimer’s.

Dementia affects more than 90,000 people in Scotland and nearly one million across the UK each year.

Early diagnosis is becoming increasingly important following the recent UK approval of new disease-modifying drugs lecanemab and donanemab.

“We know that changes in the brain linked to Alzheimer’s begin years before symptoms appear,” said Dr Jennifer Lynch, medical director at NeuroClin.

“This new blood biomarker test helps us detect potential Alzheimer’s earlier, giving people access to lifestyle advice, and access to new disease-modifying treatments or research opportunities.”

The launch marks the first time a clinically validated blood test for Alzheimer’s has been available in Scotland outside a research trial setting, following national NHS trials exploring single-marker biomarker tests.

This new version uses a multi-marker approach and is now commercially available.

Developed by Lucent Diagnostics, the test is already widely used across the US, supported by multiple peer-reviewed studies and now covered by the Medicare system.

At NeuroClin, the new blood biomarker test will form part of a staged diagnostic pathway beginning with memory testing, followed by the blood test, genetic testing and specialist support where appropriate.

Dr Simon Worrell, chief medical officer at Advance Tests, said: “Bringing this diagnostic test to Scotland for the first time is a major milestone – not just for Advance Tests, but for patients and clinicians across the country.

“We are witnessing a rare and important moment in health innovation, where breakthroughs in diagnostics are aligned with breakthroughs in treatment.

“With newly approved drugs now available, and growing evidence that early lifestyle changes can delay progression, early diagnosis has never been more valuable.”

Henry Simmons, chief executive at Alzheimer’s Scotland, added: “While we wish blood biomarker tests were routinely available on the NHS, this is not yet the case.

“We welcome NeuroClin taking the lead in offering this service in Scotland, as earlier diagnosis can help people and families get answers sooner, plan ahead and access the right support and emerging treatments.”

Ageing alters the brain’s shape in measurable ways that could provide early warning signs of dementia, potentially years before symptoms appear, researchers say.

Analysis of more than 2,600 brain scans from adults aged 30 to 97 revealed significant alterations in brain geometry linked to declines in memory, reasoning and other cognitive functions.

The inferior and anterior parts of the brain expanded outward, while the superior and posterior regions contracted inward. These uneven shifts were most evident in older adults showing cognitive decline.

Researchers at the University of California, Irvine’s Centre for the Neurobiology of Learning and Memory found that people with more pronounced posterior compression performed worse in reasoning tests, suggesting these geometric markers directly relate to brain function.

“Most studies of brain ageing focus on how much tissue is lost in different regions,” said Niels Janssen, senior author and professor at Universidad de La Laguna in Spain and visiting faculty at the CNLM.

“What we found is that the overall shape of the brain shifts in systematic ways, and those shifts are closely tied to whether someone shows cognitive impairment.”

One important implication involves the entorhinal cortex – a small but vital memory hub in the medial temporal lobe.

The study suggests age-related reshaping may press this region against the hard base of the skull.

The entorhinal cortex is one of the first areas where tau, a toxic protein linked to Alzheimer’s disease, accumulates.

The findings raise the possibility that mechanical and gravitational forces may contribute to its vulnerability in Alzheimer’s – a potential disease mechanism not previously considered.

“This could help explain why the entorhinal cortex is ground zero of Alzheimer’s pathology,” said study co-author Michael Yassa, director of the CNLM and James L McGaugh endowed chair.

“If the ageing brain is gradually shifting in a way that squeezes this fragile region against a rigid boundary, it may create the perfect storm for damage to take root. U

“nderstanding that process gives us a whole new way to think about the mechanisms of Alzheimer’s disease and the possibility of early detection.”

The researchers say their geometric approach could eventually provide new markers for identifying dementia risk, potentially before symptoms emerge.

“This isn’t just about measuring brain shrinkage,” added Janssen.

“It’s about seeing how the brain’s architecture responds to ageing and how that architecture predicts who is more likely to struggle with memory and thinking.”

The patterns were replicated in two independent datasets, reinforcing the consistency of these shape changes as a hallmark of ageing.

“We’re just beginning to unlock how brain geometry shapes disease,” said Yassa.

“But this research shows that the answers may be hiding in plain sight – in the shape of the brain itself.”