Although we generally accept aging as a necessary evil, nobody would pass up the chance to slow it down. Now researchers from the University of Michigan may have found a way to do just that – in worms at least. The team has identified a molecule in neurons that, when blocked, improves motor function in older worms and increases their lifespan and general health. Better yet, similar pathways might be at work inside humans too.
The worms in question belong to a species known as C. elegans, and they're often used as models of aging and health. That's because these little critters, barely one millimeter in length, age in a way very similar to other animals, including humans, but do so over a very short, easily-monitored lifespan of about three weeks. In the past, they've been used to study the role of the brain and gut in aging, examine the genetic reasons we haven't evolved immortality, and delve into what kind of drug cocktails could extend lifespan.
"We previously observed that as worms age, they gradually lose physiological functions," says Shawn Xu, senior author of the new study. "Sometime around the middle of their adulthood, their motor function begins to decline. But what causes that decline?"
To investigate, the researchers examined the junctions where motor neurons and muscle tissue connect in the worms. There, they identified a molecule known as slowpoke potassium channel family member 1 (SLO-1) regulates those communications, reducing the neurons' activity and over time, decreasing motor function.
The team then examined the effects of blocking SLO-1. In some animals they used genetic tools to do the job, and in another group they tried a drug called paxilline. Regardless of the method used, the treated worms were found to have improved motor function later in life, and enjoyed longer lifespans than the control group.
"It's not necessarily ideal to have a longer lifespan without improvements in health or strength," says Xu. "But we found that the interventions improved both parameters — these worms are healthier and they live longer."
Interestingly, it made a difference when in the worms' lives the team gave them the treatment. The most positive effects were seen when the worms were treated in their middle age. When SLO-1 was blocked in young worms, it didn't increase their lifespan at all and instead, actually deteriorated their motor function.
The potential good news is that SLO-1 is present in other animals too, so in the future the researchers plan to conduct similar experiments in other organisms to see if the results can be replicated.
The research was published in the journal Science Advances.
Source: University of Michigan