A new study of the aging spine could inform therapeutic treatments for age-related motor deficits.
A new study led by researchers at Brown University’s Carney Institute for Brain Science offers a blueprint to help scientists prevent and reverse motor deficits that occur in old age.
As humans age, tasks that require coordinated motor skills, such as navigating stairs or writing a letter, become increasingly difficult to perform. Reduced mobility caused by aging is strongly associated with adverse health outcomes and a diminished quality of life.
Researchers at Brown led by Gregorio Valdez, PhD, the GLF Translational Associate Professor of Molecular Biology, Cell Biology, and Biochemistry, discovered that the loss of connectivity of motor neurons in the spinal cord—not the death of those neurons, as was previously thought—is what impairs voluntary movements during aging.
“This is an important fundamental discovery because it tells us that treatments are possible to prevent and reverse motor deficits that occur as we age,” says Valdez, who is affiliated with both the Center for Translational Neuroscience and the Center for Alzheimer’s Disease Research at the Carney Institute and Brown’s Center on the Biology of Aging. “The primary hardware, motor neurons, are spared by aging. If we can figure out how to keep synapses from degenerating, or mimic their actions using pharmacological interventions, we may be able to treat motor issues in the elderly that often lead to injuries due to falls.”
For the study, published in the Journal of Clinical Investigation Insight, researchers examined spinal motor neurons in three species, including humans, rhesus monkeys, and mice.
“These findings revealed that, as individuals age, motor neurons lose many of the connections that direct their function,” says Ryan Castro PhD’22, first author of the study.