How are synapses affected by Alzheimer's disease?
Published on February 24, 2021 28 min
A selection of talks on Neurology
Hello, I'm Mariana Vargas Caballero from the University of Southampton. My talk today is entitled: 'How are synapses affected by Alzheimer's disease?'
My talk will be divided into three sections. The first will deal with the basics, what is Alzheimer's disease? The second will deal with studying the disease. What tools are available to research Alzheimer's disease? The third section will ask: how does Alzheimer's disease affect the function of brain cells and their connections, and how can we use this knowledge? Let's get started. Alzheimer's disease.
Our brain allows our body and mind to function. The human brain is made of billions of cells. Neurons are the excitable cells of the brain. Together, they form brain networks that together give us the capacity to learn and remember. Synapses are the points of communication between neurons, and communicate with substances called neurotransmitters. For example, synapses that communicate via glutamate and acetylcholine are very much affected in Alzheimer's disease. Other cell types such as glia, astrocytes, and microglia clear away debris and help keep neurons healthy. These cell types go into overdrive during the disease. The vascular system is necessary to allow the blood supply that provides nutrients, and meets the high energy requirements of the brain.
Alzheimer's disease is the most common form of dementia in old people. One in five people between 85 and 89 years old will develop dementia. With age expectancy rate rising, this disease is becoming more prevalent and we have a pressing need to find a cure. Clinically, the disease is characterized by memory loss. People gradually lose their ability to think, remember, make decisions, and function independently. Sadly, Alzheimer's disease is progressive and we still don't have a cure for it. The diagrams on the top show that the brain in Alzheimer's disease shrinks. This is because of extensive cell loss in the brain. In particular, we have extensive neuron loss in the hippocampus, which is a brain area that is essential for forming new memories. At the microscopic level, we can see that clumps of molecules accumulate inside and outside neurons. We now know that these are the pathological hallmarks of Alzheimer's disease.