A Rockefeller University scientist, speaking at a discussion hosted by the Mind/Brain/Behavior Initiative Tuesday, said that anxiety may have more negative health effects than commonly expected.
The discussion with professor Bruce McEwen, head of the Harold and Margaret Milliken Hatch Laboratory of Neuroendocrinology, was titled “The Brain on Stress: How the Social Environment ‘Gets Under the Skin.’”
McEwen spoke at Harvard a day after receiving the Edward M. Skolnick Prize in Neuroscience from MIT, described by professor Jack P. Shonkoff, director of the Center on the Developing Child at Harvard, as one of the highest honors in the field.
McEwen said that the best treatments for severe stress may be found, not in medication, but through confidence-building, a well-balanced diet, and routine exercise.
So for the overworked, under-slept college student, he said, a healthy lifestyle includes good time management, prioritizing important tasks, and not becoming overwhelmed.
McEwen explained that stress is caused by a variety of medical and experiential factors.
Experimentation has shown, he said, that brain structures have a certain degree of “plasticity,” meaning that their size and conformations can be modified over time in response to environmental cues.
He said that stress can act as a cue, and “molds” the brain by changing the way it processes anxiety, mood, and memory.
While this can help elicit the appropriate immediate response from the body, chronic brain moldings due to stress, in the long-term, can damage memory, learning ability, and social behaviors.
He said chronic stress may limit the formation of new nerve cells and lead to shrinkage of the hippocampus, a brain region fundamental to forming memories.
The good news though, McEwen said, is that much of the stress-induced brain remodeling is reversible.
Routine exercise stimulates growth in the hippocampus, and exercising in groups also fosters neuron development.
McEwen’s presentation was particularly appropriate for the sleep-deprived college student.
Sleep deprivation, he said, is a major cause and result of physiologic stress.
Poor sleeping habits have also been shown to increase the levels of brain chemicals that impair sociability.
James Herman, a professor of psychology at the University of Cincinnati and director of the Stress Neurobiology Laboratory, said his research has also demonstrated the negative impact stress can have on late adolescence, at least among animals.
“The forefront [of research] now is that the brain keeps its plasticity up until adolescence,” he said.
“Our group has shown that in late-adolescence animals that are given chronic stress exposure show a much greater physiological response ... than during early adolescence or when the animals are adults,” Herman said.
