Canines are clueing scientists into the science of dementia sleep.
When older dogs with cognitive difficulties were monitored in sleep clinics, scientists found that they experienced many of the same disturbances as people with cognitive impairment. alzheimer disease.
Our furry friends also suffer from shallow and interrupted sleep in old age.
When researchers at North Carolina State University (NCSU) and their colleagues from Argentina and Hungary recorded the brain waves of 28 senior dogs during a two-hour nap, they noticed intriguing sleep cycle activity.
Like people with Alzheimer’s, male and female dogs with marked cognitive impairments napped fewer and fewer than those without cognitive impairment.
Specifically, dogs with signs of dementia showed stronger beta wave activity during naps, which is bound to wakefulness.
Alejandra Mondino, NCSU veterinary neurologist says this means that dog brains are not really asleep, or at least not entirely asleep.
Additionally, dogs with signs of dementia appeared to experience significant loss of slow-wave sleep.
“In people, slow brain oscillations are characteristic of SWS and are linked to the activity of so-called glymphatic systema transport system that removes protein waste products from the cerebrospinal fluid,” Explain NCSU veterinary neurologist Natasha Olby.
“The reduction in slow oscillations in people with Alzheimer’s and the associated reduction in the elimination of these toxins has been linked to worse memory consolidation during deep sleep.”
Perhaps the same is true of our pets. More research is needed to confirm that hunch, but the gathering of evidence suggests that dogs may be a good model for Alzheimer’s disease research.
In 2002, scientists noticed that a dog’s daily sleep-wake pattern was “drastically altered” in older canines. However, previous studies like this one relied on the surgical implantation of electrodes into a dog’s brain.
The current experiment established a non-invasive and ethical alternative, all while using the gold standard technique for human sleep assessment.
This requires placing an electroencephalogram (EEG) on a dog’s head while it naps. The instrument then records brain waves from outside the skull.
Ultimately, the dogs that slept the longest were also the best problem solvers in a diversion task. This task involved a barrier in front of a path to a treat. The dogs were scored on how well they got around the barricade.
The findings confirm what dog owners have noticed for years: older pets with cognitive impairment tend to suffer more difficulty sleeping and daytime sleepiness.
It could be that these sleep disturbances are triggering the cognitive decline, but it could also be true that the cognitive decline is causing the sleep disturbances. In all likelihood, researchers suspect it’s a bit of both.
The researchers now plan to monitor this vicious cycle in younger dogs as they age. That way, they can look for early markers of cognitive decline in pets that might also be relevant to their owners.
“Hopefully, therapeutic trials in dogs will help direct our treatment development options for people.” says Olby.
The study was published in Frontiers in veterinary science.