Neuron loss

Professor Donna Wilcock describes how neurofibrillary tangles choke neurons, causing them to die. This is one of three hallmarks of Alzheimer's disease.

This neuron loss will carry on from the tau pathology. So, you get neurofibrillary tangles inside the neuron, and eventually the neuron – we sometimes think of it as choking up. The neuron will choke on the neurofibrillary tangle and die through several processes, which could be apoptosis, or necrosis. The bottom line is the neuron will fail, will die, and what gets left behind is the tangle. Some pathologists will refer to the tangle as a tombstone, because it reflects where there was once a neuron. Ultimately, we think this neuron loss is what leads to the memory loss, because obviously if you are losing the neurons that hold the memories, then the neuron dying will cause those memories to fall out. So, that is the third hallmark.