Age-Related Decline in Motor Skills May Not be Inevitable

By Jane Farrell

Researchers have pinpointed a source of age-related motor decline, and that could lead to targeted treatments to deal with the condition.

The investigators, from the School of Medicine at The University of Texas Health Science Center at San Antonio, discovered evidence that so-called “set points” in the nervous system are not inevitably determined during development but can be “reset” with age.

“The body has a set point for temperature (98.6 degrees), a set point for salt level in the blood, and other…set points that are important for maintaining stable functions throughout life,” said study senior author Ben Eaton, Ph.D., assistant professor of physiology at the Health Science Center. “Evidence also points to the existence of set points in the nervous system, but it has never been observed that they change, until now.”

The discovery was published in The Journal of Neuroscience.

In their study, the investigators saw a set-point change that led to sharply diminished motor function in aging fruit flies.

Lead author Rebekah Mahoney, a graduate student, said, “We observed a change…indicating that the homeostatic mechanism had adjusted to maintain a new set point in the older animal.”

The change was nearly 200 percent, and the researchers predicted that it would leave muscles more vulnerable to exhaustion.

Besides impairing movement in aging animals, that new set point could increase the risk for developing neurodegeneration — the hallmark of disorders such as Alzheimer’s and Parkinson’s diseases.

A more comprehensive understanding of this phenomenon could lead to development of new therapies for those conditions.