Evolution: We sleep like the fishes
Nature
July 11, 2019
Zebrafish experience similar sleep stages as mammals, birds and reptiles, according to a paper published this week in Nature. These findings suggest that sleep as humans experience it may have emerged as far back as 450 million years ago.
Sleep has been described in all branches of the animal kingdom using behavioural criteria and, in the case of humans, the main electrophysiological hallmarks have been identified: deep and rapid eye movement (REM) sleep. These sleep states have also been found in other mammals, birds and reptiles, but it has remained unclear whether fish and amphibians, earlier common ancestors of humans, experience these same states.
Philippe Mourrain and colleagues measured brain-wide activity along with eye movement, muscle dynamics and heart rate of two-week-old zebrafish larvae during sleep. Using these measurements, the authors were able to identify the first neuronal sleep signatures in this type of fish. They identified various sleep states - including slow-bursting, deep sleep and REM - coupled with characteristic muscle signatures, including in the heart and eye. The authors suggest that these findings are likely to mark ancestral sleep functions that are essential across vertebrates.
doi: 10.1038/s41586-019-1336-7
Research highlights
-
Jun 24
Palaeontology: It sucked to be the prey of ancient cephalopodsScientific Reports
-
Jun 24
Sport science: New wearable sensor to measure neck strain may detect potential concussionScientific Reports
-
Jun 23
Scientific community: Women credited less than men in scientific paper authorshipNature
-
Jun 17
Health technology: New cost-effective smartphone test for middle ear functionCommunications Medicine
-
Jun 17
Conservation: Feral cats pushing critically endangered marsupial further towards extinctionScientific Reports
-
Jun 16
Microbiology: DNA analysis indicates origins of the Black DeathNature