Decoding why motor functions decline with age
Research has found a clue why muscles weaken with age.
According to scientists from University of Texas' health science center at San Antonio, 'set points' in the nervous system are not inalterably determined during development but instead can be reset with age.
They observed a change in 'set point' that resulted in significantly diminished motor function in aging fruit flies.
"The body has a set point for temperature (98.6 degrees Celsius), a set point for salt level in the blood, and other homeostatic (steady-state) set points that are important for maintaining stable functions throughout life," explained Ben Eaton, assistant professor of physiology at the health science center.
"Our study points towards the existence of 'set points' in the nervous system, but it has never been observed that they change, until now," Eaton added.
Eaton and team recorded changes in the neuro-muscular junction synapses of aging fruit flies.
These synapses are spaces where neurons exchange electrical signals to enable motor functions such as walking and smiling.
"We observed a change in the synapse, indicating that the homeostatic mechanism had adjusted to maintain a new 'set point' in the older animal," researchers said.
The change was nearly 200 percent and the researchers predicted that it would leave muscles more vulnerable to exhaustion.
It appears that a similar change could lead to effects on learning and memory in old age.
An understanding of this phenomenon would be invaluable and could lead to development of novel therapies for those issues as well, said the study published in The Journal of Neuroscience.
(Posted on 08-02-2014)