Breakthroughs in fluid dynamics are revealing new clues about how odd hours affect the removal of toxins in the brain.
Got the midnight watch again? Are you flying drones in the wee hours just because it’s daylight halfway around the world? A study published earlier this month in the journal Nature, and funded in part by the Army, has found that sleeping at off hours — like many in the military and intelligence fields, not to mention millions more in all sorts of jobs — can have bad neurological effects later.
You might think that getting seven to nine hours of sleep is all that’s necessary to preserve good neurological function. But researchers from the University of Rochester Medical Center found that shift work disturbs the biological processes that clear toxic proteins out of your brain.
In the same way that your body’s lymphatic system removes toxins from your bloodstream, your glymphatic system removes bad proteins from your brain. But very little is understood about the glymphatic system. It was only discovered in 2012 and it's very difficult to see and visualize because of the blood-brain barrier.
The Army Research Office, part of the U.S. Army Combat Capabilities Development Command’s Army Research Laboratory, is in a unique position to fund basic research into the area, said officials who spoke to Defense One. “We’re trying to de-risk the idea of even trying to address this system because there’s so little understood about it. There really wasn’t a lot of federal funding put behind this topic besides some at NIH that specifically focuses on the clinical issues,” said Frederick Gregory, program manager of neurophysiology of Cognition at the Army Research Office.
What the research has revealed is that the glymphatic system is deeply connected to circadian rhythms. Travel and shift work create what Gregory calls “circadian arrhythmia, for lack of a better term. It leads to some kind of desynchronization. We don’t even know what those processes are yet... Those are some of the fundamental questions that we are looking to address in this project.”
One of the promising new insights that the research has revealed: special star-shaped glial cells in the brain called astrocytes play an important role in fixing problems of circadian disruption. They may play a key role in meliorating those bad effects of odd-hour sleep.
New scientific breakthroughs in fluid dynamics are giving scientists for the first time a glimpse at the glymphs and how they work.
“In fluid dynamics, one of the things that’s become a standard tool is you see the flow with particles. You put a bunch of particles in the flow and you do that carefully so the particles don’t influence the flow.” said Matthew Munson, the program manager for fluid dynamics at the U.S. Army Research Office.
By taking images of the particles as they move, and using statistical correlations to figure out which particles moved where, scientists can map the displacement of those particles over time, which gives them what they call the velocity field.
““If you’ve got the velocity field, you can do all kinds of things to understand the physics of the flow. In a similar vein, maybe pun intended, the group we’re working with has adapted those kinds of ideas to work in the biological systems,” Munson said.
Munson says that continuing efforts on tracing and imaging will improve understanding of those only recently revealed processes.