In a healthy, aging brain, some cognitive changes are normal — but total neuronal cell death is not. Neuroscientist John Morrison debunks the myth that neurons always die as people age.
John Morrison: I’m John Morrison. I’m at U.C. Davis, where I’m professor of neurology and director of the California National Primate Research Center.
Screen Text: Do neurons die as we age?
John Morrison: That’s generally not true. Neurons die if you have Alzheimer’s disease or Parkinson’s disease or any of the neurodegenerative disorders. But if you age without neurodegeneration, you don’t lose a significant number of neurons. So, what leads to cognitive decline, in some people, is changes at the synapse, in neurons that are still alive. Which is a very positive thing because, or a very hopeful thing, because if the neuron’s still alive you might be able to intervene in a way to make the synapses healthy again. And if the neurons die, you’re in a very difficult situation therapeutically.