Investigating the effect of Alzheimer’s disease on social behaviour and anxiety

Lead researcher: Dr James Dachtler 

Institution: Durham University

Grant type: Junior Fellowship

Duration: 36 months

Amount: £244,486

Scientific title: Understanding Amygdala Neurodegenerative Mechanisms in Alzheimer's Disease

Why did we fund this project?

Comments from the Research Network:

'I value exploration of altered social conduct and anxiety states in AD because these aspects of the syndrome seem to me to cause greater distress to people affected by dementia than memory problems.'

'Dr Dachtler's investigation of the amygdala provides remarkable confirmation of what we have all observed. Behavioural change is indeed the earliest external marker of the onset of AD and intervention at this stage could well prove beneficial.'

'This area of research will encourage and help people who, like myself, have had to care for someone very close.'

What do we already know?

The best-known symptom of Alzheimer's disease is memory loss but there are many other symptoms associated with the condition. Two of these are a change in social behaviours and an increase in anxiety. 

There is some evidence that social engagement can help to delay the symptoms of Alzheimer's disease. However, people affected by dementia often withdraw from social occasions. Changes in social behaviour are often noted as one of the earliest signs of the condition, sometimes occurring up to five years before someone receives a diagnosis. 

Anxiety affects up to 70 per cent of people with Alzheimer's disease and five per cent of people with the condition experience severe anxiety. This aspect of the condition can cause great distress to both the person affected and their carer.

Both social engagement and anxiety are linked to a structure in the brain called the amygdala. It is known that the amygdala is vulnerable to the toxic clumps of amyloid protein that are characteristic of Alzheimer's disease. There is also some early evidence that the amygdala is a key contributing factor for the spread of the amyloid protein in the rest of the brain. Despite this, the role of the amygdala in Alzheimer's disease is not well-studied. 

What does this project involve?

Dr Dachtler will use mice that show symptoms of Alzheimer's disease to understand the impact of the condition on social behaviour and anxiety. He will study the effect of Alzheimer's disease on the amygdala in the mice and see if this translates to differences in their behaviour. 

The mice will be studied using a technique called electrophysiology, which can measure the electrical activity of brain cells and record changes in their function. Dr Dachtler will use this technique to explore the effect of the amyloid protein on the connections between brain cells in the amygdala. He will also use a cutting-edge brain scanning technique to determine whether the amygdala is contributing towards the spread of the amyloid protein to other brain areas in the mice. 

How will this benefit people affected by dementia?

There has not been much research to date into the effect of Alzheimer's disease on the amygdala, despite anxiety and changed social behaviours being common symptoms of the condition. This project will aid in our understanding of the effect the disease has on this overlooked part of the brain. This will help us to better understand the causes of anxiety and changed social behaviour due to Alzheimer's disease. 

This work could also give us an insight into whether the amygdala is involved in the spread of Alzheimer's disease throughout the brain. If this is the case, the amygdala could be a key target area for future treatments.