Scientists have developed a new model to study the seemingly simple nervous system of the jellyfish.

Jellyfish can live without a brain, but at the same time, solve surprisingly complex problems using a simplified nervous system. By changing their genes, scientists have come up with a new way to monitor the internal structure of animals in real time

The researchers created a model using the tiny jellyfish species Clytia hemisphaerica. An adult grows up to 1 cm in diameter, so scientists easily placed the entire jellyfish under a microscope and observed its entire nervous system.

The human brain is the “control center of the body,” but jellyfish do not have such a structure in their nervous system. They have no head, and instead of a brain, they have a nerve ring with knots at the edge of an umbrella. From this ring branch off the processes of nerve cells, which give commands to the muscles – this is a diffuse “network” of nerves, which diverges symmetrically from the center of the body. According to a 2013 article in Current Biology, some jellyfish lack nerve networks and only have nerve rings, but Clytia hemisphaerica has both structures.

To learn more about the jellyfish’s nervous system, scientists altered the genes of C. hemisphaerica. They adjusted its luminescence using CRISPR for more visual observations, the scientists used CRISPR. The scientists then conducted some visual experiments to see which neurons light up in jellyfish during their typical feeding behavior. They found that when they clung to the shrimp or came into contact with a food supplement, a group of neurons that were physically close to the shrimp suddenly ignited. The research is published in the journal Cell.

According to biologists, they did not expect to see this level of organization within a seemingly unstructured neural network. In the future, they will study how jellyfish control other behaviors, not just feeding. Also, experiments will be carried out on different types of jellyfish.