As far back as the 13th century, Roger Bacon wrote that old age is the home of forgetfulness. Since we are now growing older than ever before, more and more of us are having to deal with dementia. World Alzheimer's Day provides a great opportunity to take a look into the world of dementia.
Inside the head of an Alzheimer's patient
We can see the closed archives of the memory. The corridors that might take us there are dark and obstructed. The lift is not working. Parts of the staircase appear to have crumbled. Here and there we come across pieces of memory, discarded on the floor. They are undated, and each piece is lying in a large pile of random isolated memories.
What causes Alzheimer's?
To this day, we are unsure what causes our brains to stop functioning properly. What we do know is that the onset of dementia is preceded by the formation of amyloid protein deposits (also known as amyloid plaques) in the brain. These protein deposits can be observed in the brains of all dementia patients. Are amyloid plaques the cause of the decline of the brain, or are they a by-product of a so far unknown process that eventually results in dementia? We do not yet know the answer to that question.
Similar clinical picture
Amyloid plaques also form in the brains of old monkeys. These plaques have the same composition and distribution as the plaques found in human brains. The dementia process in monkeys can be accelerated by activating their immune system. To be able to find the key to treating dementia, we will have to gain a better understanding of that underlying process. That is why monkeys are highly relevant to Alzheimer's research. They allow us to determine which processes cause the onset of the amyloid plaques that precede dementia.
If you live long enough…
BPRC keeps monkeys of all ages. In the wild, marmosets typically live for about 10 years, but because of the excellent care they receive at BPRC, they may live for 15 years or longer. These old monkeys show that if you live long enough, you may fall victim to ageing. It is precisely these animals that may teach us a lot about the process underlying Alzheimer's disease.
Much work still to be done
BPRC uses animal models to contribute to this research. Conducting research using cells in a Petri dish is not an option here, because Alzheimer's is a complex disease in which several parts of the brain are involved, with major interactions in the body. Even the gut flora play a part. These interactions cannot be isolated in a cell culture. We need complete bodies. For ethical reasons, we cannot use human bodies.