Caltech researchers have created a genetic toolkit specifically for toying with Clytia hemisphaerica, a jellyfish species that grow to be roughly a centimeter in diameter when fully mature. The research findings have been shared by Caltech News Blog and were published in the journal Cell. The microscopic organisms have been genetically made to glow with fluorescent light when their neurons are stimulated using this toolset. Researchers can observe the glow of a jellyfish’s neuronal activity as it behaves naturally since it is transparent. To put it another way, the researchers can read a jellyfish’s mind as it feeds, swims, evades predators, and so on, in order to figure out how the animal’s relatively rudimentary brain coordinates its behaviors.
The experiment was carried out on a Clytia hemisphaerica, a jellyfish with a diameter of around one centimeter when fully developed. The jellyfish was genetically engineered such that when its neurons were stimulated, they all lit up. They were then able to observe the translucent creature’s neurological activity as it functioned organically.
Because jellyfish brain activity is an extreme outlier in laboratories, the researchers were interested in researching it. Worms, flies, fish, and mice are the most widely used since they are all genetically linked.
Unlike human brains, jellyfish brains are dispersed throughout their entire bodies, with each body part acting independently. Even if the remainder of the animal’s body is removed surgically, a jellyfish mouth can continue to “feed.” The researchers were puzzled as to how this dispersed nerve system coordinates and orchestrates behavior. They started by watching the jellyfish’s brain activity while it ate.
When a brine shrimp is caught, the jellyfish folds its body to bring the tentacle to its mouth while also bending its mouth towards the tentacle, posing the question of how it does this with an unstructured and radially symmetric brain.
The researchers plan to use the jellyfish as a platform for further research into neuroscience, including determining the extent of modularity inside the nervous system and how these modules interact with one another. The study’s purpose is to not only better understand jellyfish brains, but also to use them as a springboard for investigating mechanisms in more complicated systems. A jellyfish’s brain contains roughly 5,600 neurons, making it a comparatively simple organism.
