A neuroscience conference in Washington, D.C. this week could stress you out all by itself. Lab rats put in stressful situations — like being immobilized and forced to listen to loud rock music — grow fewer fibers that connect neurons. Stress isn’t that great for people, either.

“Stress causes neurons (brain cells) to shrink or grow,” said Bruce McEwen, a neuroscientist at Rockefeller University in New York. “The wear and tear on the body from lots of stress changes the nervous system.”

He said that stress is “particularly worrying in the developing brain, which appears to be programmed by early stressful experience.”

Stress in early life, even in the womb, can later lead to undesirable changes in behavior and the ability to learn and remember. Other consequences may be substance abuse and psychiatric disorders, researchers said…

“Pre-natal stress can change the brain forever,” said Tallie Baram, a neurologist at the University of California, Irvine. “Stress changes how genes are expressed throughout life.”

[1899 drawing of pigeon neurons by Santiago Ramón y Cajal, Wikimedia Commons]