Tackling Alzheimer’s disease with advanced imaging techniques

Alzheimer’s disease (AD) affects thousands of Australians each year. Treatments and preventative measures can improve quality of life for patients, but there is currently no cure for the disease.

That’s why the AEHRC’s Ying Xia is leading a project to enable earlier diagnosis and more effective treatment of AD.

Her research explores the disruption of signal transmission in the brain, which contributes to the cognitive symptoms of AD.

Sending the right signals

Messenger molecules, called neurotransmitters, transmit signals within the brain and to the body. Low levels of certain neurotransmitters lead to cognitive symptoms like attention and memory issues.

Acetylcholine, the key messenger of the brain’s cholinergic system, is heavily involved in cognitive function.

“Low levels of acetylcholine in the brain have been linked with Alzheimer’s. Drugs that target the cholinergic system by increasing levels of acetylcholine have been used for some time,” Ying said.

However, these drugs are currently only effective in 30-35 percent of cases. Ying hopes to gain a better understanding of the cholinergic system to inform the use of these drugs to greater effect.

Artificial intelligence for Alzheimer’s disease

Her team recently published a study on the links between Alzheimer’s disease, brain function, and the state of the cholinergic system.

They used artificial intelligence methods to analyse magnetic resonance imaging (MRI) brain scans of participants in the Australian Imaging, Biomarkers and Lifestyle (AIBL) study of ageing.

“We’re interested in differences in the basal forebrain, the area of the brain responsible for producing acetylcholine,” Ying said.

They observed shrinkage of the basal forebrain that correlated with known AD-related changes in the brain.

Interestingly, changes to the acetylcholine-producing region of the brain seem to occur well before cognitive symptoms of Alzheimer’s appear.

“Our findings offer a method to potentially detect Alzheimer’s disease earlier,” Ying said.

Tackling Alzheimer’s with targeted treatment

Understanding the cholinergic system and changes induced by AD informs targeted, more effective treatment.

“We can use advanced imaging techniques to identify decline of the cholinergic system in patients that don’t yet have cognitive symptoms. It may be the case that if we can give the drugs early enough, we can slow the progression of cognitive decline,” Ying said.

Unfortunately, not all patients will benefit from cholinergic drugs.

“We’ve shown we can identify changes in the cholinergic system. This helps us identify patients who may benefit while avoiding giving the drugs when there’s likely to be no benefit, preventing people from experiencing unnecessary side effects,” she said.

The goal is to use these existing drugs more effectively alongside new treatments to improve quality of life for Australians with Alzheimer’s disease.