Sleep Patterns of Australian Dragons Discovered

For a long time, scientists have long been puzzled over the nature of sleep across different animal species. A new study, however, cast a new light on how sleep occurs in a group of lizards known as Australian dragons. It seems that dreaming is not just a monopoly of mammals and birds. Apparently, lizards dream too.

In recently published study featured in the journal Science, German researchers studying five Australian bearded dragons seem to have uncovered startling evidence that reptiles actually dream which could trigger fundamental revamp of previously held notions about sleep.

For the first time, scientists discover that reptiles also experience phases of sleep similarly experienced by people- the rapid eye movement (REM) sleep and another stage known as slow-wave sleep.

Interestingly, dreaming occurs during the REM sleep stage which begs the question, what do lizards dream about when they sleep?

"If you forced me to speculate and to use a loose definition of dreaming, I'd speculate that those dreams are about recent notable events: insects, maybe a place where there are good insects, an aggressive male in the next terrarium, et cetera," said neuroscientist Gilles Laurent of the Max Planck Institute for Brain Research in Germany as quoted by ABC Australia.

He jokingly added saying, "If I were an Australian dragon living in Frankfurt, I'd be dreaming of a warm day in the sun."

Studying sleep was never the intended goal of the German scientists. Laurent and his team were more actually interested with how the cortex works using lizards as a lab example to study that part of the brain. Throughout their research, the scientists implanted electrodes in the brain of the Australian dragons and record the reptiles' brain activity.

"In the middle of some experiments we were doing, we decided to let the recordings go overnight after a day's work, just to see what would happen during the night," Laurent exclaimed as quoted by Live Science.

"And upon analyzing the results, there were interesting oscillations of activity that were very regular, that suggested the potential existence of sleep-related patterns of activity in the brain."

In the course of the study, the researchers discovered two distinct sleeping patterns among the lizards. One pattern is characterized by high-frequency wave forms of 20 cycles per second. The other one consisted of low-frequency wave forms of just less than 4 cycles per second.

What are the implications of the study?

From an evolutionary standpoint, this discovery could raise more questions than answers and undermine previously-held notions about sleep as well as its patterns and functions across the animal world.

While scientists admit that more studies are required to see any similarity of function of brain wave patterns across different animal species, the provocative results suggest that these REM and brainwave patterns during sleep can be traced all the way back to the pre-ancient common ancestor of all animal species.

"There is something that goes on during sleep that is important to the function of all animals," remarked neuroscientist Matt Wilson of the Massachusetts Institute of Technology in Cambridge as quoted by the Science Mag.