Monkey Brains

Podcast

Monkey Brains

Transcript

Scientists find that minds do keep expanding as we get older. I’m Bob Hirshon and this is Science Update.

Contrary to popular belief, scientists have found that brains do add more brain cells as we get older. That's according to research in monkeys at Princeton University. Psychologist Charles Gross led the study.

Gross:
"For over a hundred years it's been assumed that there are no new neurons that are added to the brains of adults. Rather, it was assumed that we have all the neurons that we're ever gonna have, soon after birth."

But new research has stood that idea on its head. Earlier this year, scientists found new cells being added top the hippocampus, a primitive part of the brain. And now, Dr. Gross found new nerve cells being added to another part of the brain - the cerebral cortex.

Gross:
"The cerebral cortex is the highest area of the brain. // It's where the highest processes of perception, cognition, decision making and thinking occur."

And while Dr. Gross' work was done in monkeys, he says that it's almost certain that exactly the same thing is happening in humans.

Dr. Gross says that the finding does hold hope for possible treatments, someday, of brain diseases like Parkinson's disease and Alzheimer's. But for right now, just the fact that our brains put on more cells, is quite a breakthrough in itself.

For the American Association for the Advancement of Science, I’m Bob Hirshon.

Making Sense of the Research

The cells in most of our organs reproduce rapidly. Our hearts, livers and kidneys are constantly regenerating. But the brain grows while we're young, and then the cells stop reproducing. At least that's what scientists always thought. Now they're finding that some brain cells do reproduce. Understanding how and why could be important for treating brain disorders and injuries.

The Science Update you just heard sheds light on science as an on-going, self-corrective process, and on how animal models can reveal important information on humans, when human subjects can't be used.

Now try to answer the following questions:

1. What recent discovery about the brain have scientists made? Why is this discovery so important?
2. How does this finding relate to previous theories about the brain?
3. What are the implications of this finding?
4. What additional questions might this finding raise?
5. The idea that brain cells are constantly regenerating is contrary to commonly-held beliefs about the nature of the brain. Scientists have had to revise previous theories in light of this new research. Can you think of additional examples that show science as a self-corrective process?

Going Further

Go to Total Recall from the National Wildlife Federation website to explore how the regeneration of brain cells in chickadees helps them make decisions about where to store food and find it later.

For more information on the structure and development of the brain, visit Neuroscience for Kids.