Researchers at the University of Michigan Life Sciences Institute have found the cause of declining motor function in aging worms. The experts have identified a molecule that can be targeted to improve motor function, and they speculate that similar pathways may be involved in the aging process of mammals as well.
The deterioration of motor function is a natural part of aging among both humans and animals. The study was focused on the aging patterns of millimeter-long roundworms called nematodes, which only live for about three weeks.
“We previously observed that as worms age, they gradually lose physiological functions,” said study senior author Professor Shawn Xu. “Sometime around the middle of their adulthood, their motor function begins to decline. But what causes that decline?”
To investigate how the interactions between cells shifted as worms aged, the team examined the regions where motor neurons communicate with muscle tissue. The researchers found that a molecule called SLO-1 regulates these communications. The molecule slows down the signals from neurons to muscle tissue, which reduces motor function.
After manipulating SLO-1, the experts observed two major effects in the roundworms. They maintained motor function later into their lives, and they also lived longer than normal roundworms.
“It’s not necessarily ideal to have a longer lifespan without improvements in health or strength,” said Professor Xu. “But we found that the interventions improved both parameters – these worms are healthier and they live longer.”
The study also revealed that the timing of the interventions drastically changed the effects on both motor function and lifespan. When SLO-1 was manipulated during the early days of the worm’s’ life, there was no effect on lifespan, and there was even a detrimental effect on motor function in the young worms. On the other hand, when the activity of SLO-1 was blocked in mid-adulthood, both motor function and lifespan improved.
Professor Xu hopes these findings will lead to future research that examines the role of the SLO-1 channel in other organisms.
“Studying aging in organisms with longer lifespans is a major investment. But now we have identified a molecular target, a potential site and specific timing, which should facilitate further investigation.”
The study is published in the journal Science Advances.