Dendritic spines linked to Alzheimer’s resilience

26th Oct 2017

Understanding why some people are at more risk for developing diseases is a major challenge for 21st century neuroscientists.

A research group led by assistant professor Jeremy Herskowitz at the University of Alabama at Birmingham recently uncovered why some people seem to be resistant to Alzheimer’s disease.

The study, published in the journal Annals of Neurology, looked at the structure of neurons in the outer layer of the brain.

In Alzheimer’s disease proteins known as tau and amyloid misfold and accumulate, which is associated with neuronal death. The extent of this pathology is often linked to the severity of the disease.

But up to 50% of the ageing population appear to be resistant to the clinical symptoms of Alzheimer’s disease – such as memory problems – despite having similar tau and amyloid build-up.

The study looked at brain tissue from healthy controls, people with Alzheimer’s disease, and those with protein build-up but who appeared ‘Alzheimer’s-resistant’.

Neurons, like bramble branches, have small protruding structures known as dendritic spines. The density and shape of these spines have been linked with several brain functions, such as learning and memory. 

Using a high-resolution staining technique, they compared the microstructure of neurons in a region of the brain known as Brodmann area 46, which is commonly affected in Alzheimer’s disease.

Herskowitz and his colleagues demonstrated that whilst Alzheimer’s disease patients had fewer dendritic spines on their neurons, people with the resistant form had far more spines compared to healthy controls.

The results show for the first time that there is a cellular and structural basis to resilience to Alzheimer’s disease.

Further understanding of these mechanisms could identify new therapeutic targets for Alzheimer’s disease and other forms of dementia.

Read the full paper here.