Transcript

My name is John Morrison, and I'm at UC Davis, where I'm Professor of Neurology and Director of the California National Primate Research Center.

That's generally not true. Neurons die if you have Alzheimer's disease or Parkinson's disease or any of the other neurodegenerative disorders. But if you age without neurodegeneration, you don't lose a significant number of neurons. So then what leads to cognitive decline in some people is the changes at the synapse in neurons that are still alive, which is a very positive, positive thing, because they're a very hopeful thing, because if the neurons still alive, you might be able to intervene in a way to to make the synapses healthy again. And if the neurons die, you're in a very difficult situation therapeutically.