Stress on worms could give insight into human brain development
Worms and humans might have more in common neurologically than researchers ever thought, particularly when it comes to stress.
A recent study from the National Institute of Health put male worms under duress during their puberty to study how that stress affected their neurological wiring, interestingengineering.com wrote.
They discovered stress from developmental trauma plays a role in how neurons function.
Oliver Hobert, PHD, professor of biological sciences at Columbia University in New York City, said, “We found that environmental stress can permanently and profoundly impact the connectivity of a developing nervous system.”
Holbert served as a senior author of the study published in Nature.
Hobert and graduate student Emily Bayer studied the nervous systems of Caenorhabditis elegans, or C. elegan worms. Hobert’s lab is familiar with the tiny see-through worms; previous research teams with Hobert’s lab showed how sexual maturation in worms could reshape their neural circuits in male worms. This new research looked at the opposite effect. Graduate student Emily Bayer discovered that exposure to stress — namely starvation — before hitting sexual maturity interrupts the brain’s wiring processes. Bayer also suggested in her research that it’s controlled in part by serotonin, a neurotransmitter most humans associate with depression.
“I was totally surprised. In fact, I never thought stressing the worms out would matter,” said Bayer. “It wasn’t until I saw differences in their circuits that I realized that stress could remap their wiring diagrams.”
Bayer said the experiment was slightly accidental. She left several of the animals unattended for a few weeks. This led to the worms to completely pause in their developmental state and enter something called the ‘dauer state’.
“Basically, if immature worms sense stress of any kind they can temporarily halt their normal growth for months and then restart it when the stress passes. This temporary freeze in the growth process is the dauer state,” said Hobert.
Bayer put the worms back in their normal environment and they grew to full adulthood. But she noticed something unusual as she observed their nervous systems.
Typically, the neuronal connections in a male’s tail go away during sexual maturation in a process called ‘pruning’. However, Bayer noticed that unfinished connections in the stressed worms were still there. She also noticed that pruning is controlled by the opposite effects of both serotonin and octopamine — the ‘fight or flight’ neurotransmitter.
Stressed worms had problems mating; they spent less time in contact with the hermaphrodite worms than the mature males.
HOBERT LAB, COLUMBIA UNIVERSITY, NY.