The Brain Tour

From movement to memory, find out what different parts of the brain do, and how they can be affected by dementia.

brain tour
  • Personality
  • Memory
  • Ordering
  • Emotions
  • Vision
  • Language
  • Body
  • Spatial
  • Behaviour

The Human Brain

Brain Tour

Click the hotspots to discover how your brain works and the effect dementia has on it.

Join us on a tour of the brain, the most complex structure in the known universe. From movement to memory, find out what different parts of the brain do, and how they can be affected by dementia.

Alzheimer's Research UK scientists learn more about the brain and dementia every day and the Brain Tour showcases our progress. With hundreds of projects underway looking at causes, diagnosis and treatment, you are helping us defeat dementia.

What it does

Enclosed by the tough protective casing of the skull, our brains are the centre of our nervous systems. The brain monitors and regulates our actions and reactions. It constantly receives information from our senses, rapidly analysing and co-ordinating our responses to things we see, hear, touch and taste.

The brain is also our centre of learning. It forms and stores our memories. It's involved in speech, abstract thought and consciousness as well as informing our personality and emotions. An adult brain weighs about 1.5kg (3.3lb) and contains about 90 billion nerve cells. As well as nerve cells our brains have about 90 billion other cells, plus blood vessels to help supply the nutrients and oxygen it needs. During dementia, nerve cells in different areas of the brain become damaged and eventually die. A lot of research we're supporting aims to stop this damage and protect the brain from harm.

Nerve cells, proteins, plaques & tangles'

nerve cells

Nerve cells

Our brains have about 90 billion nerve cells. They are specialised in sending messages to each other. They allow us to sense and respond to the world around us.

During dementia, cells lose the ability to communicate with each other and eventually die. This loss of nerve cells causes the symptoms of dementia, for example memory loss, as the brain becomes unable to function in its usual way. What causes nerve cells to die in dementia is a hot topic for our research. Our scientists are finding out more every day about how we can protect brain cells from harm, moving us closer to new dementia treatments. Nerve cells have a body or hub and many long, thin branches (axons and dendrites) that extend from the body. These reach out to other nerve cells. The points where nerve cells connect to each other are called synapses. Nerve cells use both tiny electrical impulses and specialised chemicals to send messages to each other.

protein cells

Proteins, plaques & tangles

Proteins are a vital part of our bodies. They have thousands of jobs to do. Different proteins make up our skin, hair and bones. Other proteins move our muscles or digest our food.

There are different diseases that can cause dementia, including Alzheimer's disease, dementia with Lewy bodies and frontotemporal dementia. These share a common feature - an excessive build up of proteins in the brain. In Alzheimer's there are two culprit proteins, called amyloid and tau. They build up during the disease, become toxic and harm the brain and nerve cells. Amyloid makes sticky clumps or 'plaques' where as tau forms tangles, twisting inside cells and blocking them. In dementia with Lewy bodies (DLB), the culprit is a protein called 'alpha-synuclein'. It forms tiny spheres which are toxic. During frontotemporal dementia several different proteins can build up. We're supporting a lot of research looking at ways to stop these proteins from building up and causing harm.