What meanders between obstacles? For example, a colorful robot snake? In fact not, but close. In this photo, an eel of engines and sensors winds ashore and not only reveals about the special skills of the slim fish, but also about the landing of the vertebrates about 400 million years ago.
Eale can not only swim in the water, but also move on land. Another special feature is the ability of the fish to continue moving themselves with damaged spinal cord – most other vertebrates would paralyze this. The reason for this is segments made of so -called “central sample generators”. These neuronal networks generate the rhythmic meandering movements typical of the eels and are controlled by pressure on the skin of the fish and the stretching of their muscles. Since the central sample generators work largely independently of the rest of the spinal cord, the eels can maintain their meandering movements even after a spinal cord injury.
So far, it was difficult to examine this interaction in living animals. That is why researchers around Kotaru Yasui from the University of Tōhoku have now developed a mathematical model for such a central model generator and installed it in the photo in the robot room. The tests on water and on land not only confirmed earlier studies on the movement sequences of healthy and spinal cord -damaged eels, but also that skin pressure and stretching of the muscles are used when moving. This indirectly reveals more about the first landing gear of our vertebrate ancestors.
“The discovery that a neuronal circuit for swimming also enables the locomotion on land indicate that the evolutionary transition of vertebrates from water to the country may not require completely new neuronal circuits,” explains Auke IJSpeer from the Federal University of Technology Lausanne. “Instead, existing aquatic circuits could have been converted – a principle that contributes to our understanding of the evolutionary origins of movement control.”
