Duke Forward News

Does immune system function influence brain structure? Can the adult brain grow new nerve cells?

April 05, 2013

The complexity of the brain—its inner pathways, neurons, and circuits—has made it one of the most challenging parts of the human body to study and understand. But because of advancements in technology and innovative collaborative efforts by faculty at the Duke Institute for Brain Sciences (DIBS), researchers are gaining new insights into how the body’s most important control system works and are revolutionizing our understanding of human behavior, emotion, and disease.

Professor Michael Platt, director of DIBS and the Center for Cognitive Neuroscience, gives us important facts about the brain that we didn’t know just 10 years ago, thanks to the hard work of neuroscientists at Duke and elsewhere.

Platt, along with his colleagues from DIBS will participate in the “Brain Science & Our Creative Culture” panel at Duke Forward in New York on April 26. This is one of an extraordinary series of “On the Road” events celebrating the launch of the $3.25 billion Duke Forward fundraising campaign and what it will mean for the university’s future. Learn more about ways the campaign will enrich the Duke experience at dukeforward.duke.edu.

1. Immune system function influences brain structure and operation. Researchers previously thought that the brain was mostly isolated from the body’s immune responses. Pioneering new studies by Duke neuroscientist Staci Bilbo demonstrate that infections early in life, even before birth, can affect the brain’s growth and development. And these changes impair learning and memory later in life. Similar immune-related responses may shape the impact maternal obesity has on offspring brain structure and function.

2. The adult brain can grow new nerve cells. Moreover, exercise and nutrition can enhance this new growth. Studies by Duke neuroscientist Christina Williams show that supplements with choline—a nutrient found in eggs—improve brain-cell growth and subsequent learning and memory. Exercise also betters the growth of new neurons as well as learning and memory.

3. We’re hardwired to learn—and also to be kind. Special brain cells known as "mirror neurons" underlie learning and empathetic kindness. Duke neuroscientist Rich Mooney has shown that mirror neurons in sparrows respond both when the bird hears another bird sing and when they sing the song themselves. These mirror neurons are critical for imitating other birds' songs. Platt’s recent work with monkeys has shown that when they decide to give a reward to another monkey, mirror neurons respond the same way they would respond if the monkey received a reward himself. This suggests that these cells play a role in empathy and shared reward.

4. Adult humans have a "number sense" that emerges early in life, before language or mathematics. This number sense is shared with nonverbal animals. Duke neuroscientist Elizabeth Brannon has shown that the number sense in animals and human adults and babies is remarkably similar. She and others have also found that babies who have a better number sense eventually perform better on standardized math tests in school, suggesting the number sense provides a scaffold for learning math. She's currently working on ways to improve the number sense in infants and toddlers as a way of improving their math skills later in life.

5. Economic constructs like value, utility, risk, and ambiguity are encoded in specific brain circuits. Platt and fellow Duke neuroscientist Scott Huettel have shown that these fundamental economic variables are encoded by brain cells in specific areas. Moreover, brain cell activity in these areas is different in people who make different kinds of decisions. People who are risk-averse, for example, have a different pattern of activity than people who are risk-seeking. Children who are more adult-like in their decisions also show more adult-like patterns of brain activity.

Photo by Scott Van Manen

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