An optical device that can detect chemical brain changes that occur in the very earliest stages of Alzheimer’s disease could help design effective therapies.
Researchers at Strathclyde University found that they could track the formation of protein clumps that are linked to Alzheimer’s disease using short pulses of light.
One of the key causes of Alzheimer’s is thought to be the aggregation of defective proteins that coalesce to form fibrils and plaques, subsequently contributing to neuro-degeneration and the symptoms of the disease.
The process is still poorly understood by scientists, but it is believed that the early stages of plaque formation — when protein monomers start to bind together — is a central part of the resulting cascade.
Unfortunately, current techniques are only sensitive enough to detect large plaques at the advanced stages of the disease.
In their latest research, the team found that intermediate protein aggregates naturally emitted a fluorescent signal when exposed to a certain wavelength of light that could then be detected using modified spectroscopy.
Project lead Prof Olaf Rolinski of Strathclyde explained that the main advantage of the system is that it is potentially non-invasive and doesn’t need contrast agent or chemical tags like many other medical-screening techniques.
‘We just excite with photons of light and collect photons, we don’t have to insert any needles, any electrodes, apply any current, or add any chemicals — it’s an interaction by light,’ he told The Engineer.
However, Rolinski said there were major challenges to overcome before the technique could be used diagnostically, as the wavelength of light used is easily absorbed by surrounding tissues.
In the short term it could be used in vitro to analyse how changes in protein sequence, concentration or conditions affect the rate of aggregation and conformation of plaques. This could help to identify stages in aggregation that could potentially be blocked with drugs.
‘It is important to fully understand the very early stages of amyloid aggregation as it can help in the design of more effective therapeutics not only for the Alzheimer’s but for all amyloidoses,’ Rolinski said.